Alternative 2: East Yosemite Valley Utilities Improvement Plan with Merced River Crossing at Housekeeping Camp

Alternative 2 would implement the East Yosemite Valley Utilities Improvement Plan with a Merced River utility crossing at Housekeeping Camp. Under Alternative 2, the park would develop consolidated utility corridors following existing utility lines or existing or proposed transportation corridors. This alternative would also reduce utility infrastructure within the Merced River and its floodplain and from areas identified for ecological restoration in the Yosemite Valley Plan. Alternative 2 would also ensure efficient utility service to new facilities proposed under the Yosemite Valley Plan.

Alternative 2 also includes wastewater projects currently planned and required by the California Regional Water Quality Control Board to address recent wastewater releases. Those projects currently planned that could be eliminated by implementation of the East Yosemite Valley Utilities Improvement Plan (primarily in the Ecological Restoration and Camp 6/Cook’s Meadow areas) have been removed from the analysis of impacts for this alternative.

Natural Resources

Soils

Analysis

Alternative 2 would result in short-term, adverse effects on soils in Yosemite Valley due to construction activities; however, most of the areas proposed for utility corridor construction have been previously disturbed by utilities, transportation facilities, or other development. Implementation of Alternative 2 would remove utility infrastructure in environmentally sensitive areas such as wetlands, and would result in beneficial long-term effects on wetland soils by allowing for more natural subsurface water flows.  Impacts to soils associated with Alternative 2 are summarized in table IV-7 and described by subarea below.

Happy Isles. Construction of the utility corridor in the Happy Isles area is expected to require disturbance of 6.9 acres of soils classified as other, in addition to 0.6 acre disturbed by existing utility repairs described under Alternative 1. Soil excavation could result in disruption of the existing soil profile, thus interrupting the natural chemical, physical, and biological process in the soil. The localized removal of vegetation and use of heavy equipment could increase soil erosion and result in soil compaction in these areas.

The area proposed to be affected is within an existing water utility corridor and park operations access trail. The area has been previously disturbed by utility installation and maintenance, as well as access use by vehicles and park operations staff on horseback. There may be some additional disturbance adjacent to the existing water line and access trail to accommodate the new water line. Construction impacts would be mitigated through minimizing the area disturbed, salvaging the existing soils for use as backfill, implementing Best Management Practices during construction to reduce soil erosion and transport, regrading the area to its preconstruction contours, and revegetating the area with native plants when construction is complete. Impacts to soils in this area are expected to be local, long-term, minor, and adverse.

 

^{a   Includes repairs to existing wastewater lines as described in Alternative 1, as well as construction of proposed consolidated utility corridors.}

 

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Campgrounds. Construction activities in this area would include construction of multiple integrated utility corridors and removal of utility infrastructure from North Pines Campground. Utility corridor construction in this area would be coordinated with campground redevelopment activities in this area. The proposed corridors include replacement of the existing water utility crossing of the Merced River at Clark’s Bridge with a consolidated utility corridor to the proposed North Pines Amphitheater site. Construction of the integrated utility corridors is expected to require disturbance of approximately 32.2 acres of soils, including approximately 2.5 acres classified as highly valued, 26.8 acres classified as resilient, and 2.9 acres classified as other. Repairs to existing utilities within the area (discussed under Alternative 1) are expected to impact up to another 2.2 acres of soil, of which 1 acre is classified as highly valued, 0.9 acre as resilient, and 0.3 acre as other. Construction activities are expected to have local, long-term, minor adverse effects on highly valued soils and soils classified as other. Construction is expected to have local, long-term, moderate impacts on resilient soils. These can be mitigated to a minor level using mitigation measures discussed below.

Removal activities could temporarily disturb up to 19.6 acres of soils. Removal of utilities in the Campgrounds area would include excavation and removal of existing Tenaya Creek and Merced River utility crossings in this area, excavation and removal of utility lines in the former North Pines Campground, and removal of an electric transformer and lift station from the former North Pines Campground. The 19.6 acres that could be disturbed by utility removal actions include 15.8 acres of highly valued soils and 3.8 acres of resilient soils. These removals are planned to coincide with other ecological restoration activities proposed in the Yosemite Valley Plan.  The areas that would be disturbed are within and adjacent to existing utility corridors that have been previously disturbed, are currently developed as campground areas, and are proposed for redevelopment under the Yosemite Valley Plan (see Appendix H, Projects included in the Cumulative Impact Analysis). The utility removals would result in beneficial effects from allowing more natural subsurface water flows to resume within these highly valued and hydric soils. Over the long run, this should allow the restoration of soil profiles and enhancement of biological activity. Thus, removal activities are expected to result in local, short-term, moderate, adverse effects on highly valued soils in the removal areas, but are expected to have local, long-term, moderate, beneficial effects on soils in these areas.

Construction impacts would be mitigated as discussed for the Happy Isles area above, with particular attention to erosion control measures and bank stabilization during construction work within Tenaya Creek and Merced River.

Ecological Restoration Area. Activities proposed in this area under Alternative 2 include construction of an Ahwahnee Bridge Utility Corridor from the Lower Pines Lift Station. The proposed utility corridor construction could disturb approximately 6.4 acres of soils, of which 5.9 acres are classified as highly valued and 0.5 acre is classified as resilient. Soil disturbance could result in local, long-term, moderate, adverse impacts on highly valued soils and negligible impacts on resilient soils. Impacts to the highly valued soils can be mitigated by salvaging highly valued soils from excavations and reusing these soils as fill, and by using trench plugs where needed to ensure that construction does not create preferential groundwater pathways that would alter subsurface hydrology that supports hydric soils.

Utility removal activities in this area include excavation and removal of Merced River utility line crossings between the Ahwahnee and Stoneman Bridges, four electric transformers, and other utility infrastructure located throughout the area identified for ecological restoration in the Yosemite Valley Plan. The areas that would be affected are within existing corridors that have been previously disturbed and developed as campgrounds, but which are currently designated for ecological restoration. Removal activities in this area would be coordinated with ecological restoration plans currently under development, which are likely to propose removal of fill and restoration of natural conditions in these areas. Removal activities in this area could disturb up to 44.6 acres of soil, and would be coordinated with ecological restoration activities in the area. The 44.6 acres that could be disturbed by removal actions include 41.7 acres of highly valued soils, 0.5 acre of resilient soils, and 2.5 acres classified as other. These removals are expected to have local, short-term major adverse effects on previously disturbed highly valued soils, but are expected to result in local, long-term major benefits to soils from restoration of natural hydrologic and biological processes.

Construction impacts would be mitigated as described for the Campgrounds and Happy Isles areas above.

The Ahwahnee. Proposed utility corridor construction in The Ahwahnee area is expected to result in the disturbance of approximately 13.9 acres of soil, including 4.7 acres classified as resilient and 3.1 classified as other. Repairs to existing utility facilities (described under Alternative 1) in this area could impact up to another 3.6 acres, of which 1.8 acres are classified as highly valued, 1.5 acres are classified as resilient, and 0.3 acre is classified as other. Construction activities associated with the proposed corridors and repairs would have local, long-term, minor, adverse effects on highly valued, resilient, and other soils.

Existing wastewater lines through Ahwahnee Meadow are proposed to be pipe burst and abandoned in place. Electrical lines running through Ahwahnee Meadow would be excavated and removed to allow for natural groundwater movements through the meadow. Water lines to the southeast of The Ahwahnee would be pipe burst and abandoned in place. Pipe bursting and utility line removal activities are expected to impact up to 16.6 acres, including 7.7 acres classified as highly valued soils, 8 acres classified as resilient soils, and 0.9 acre classified as other. The pipe bursting, abandonment, and removal actions would have local, short-term, moderate, adverse effects on soils related to construction activities. This would be expected to result in local, long-term, moderate beneficial effects on highly valued soils related to restoration of more natural groundwater flows that could enhance soil restoration over time and reduce future impacts associated with maintenance of the utility facilities. Short-term effects on other soils are expected to be local, minor, and adverse and long-term effects from utility removals are expected to be local, minor, and beneficial.

The areas that would be affected are within existing corridors that have been previously disturbed and developed. Construction impacts would be similar to those identified for the Happy Isles and Campground areas above. Adverse construction effects such as soil erosion and compaction would be mitigated as discussed above.

Curry Village. Activities proposed in the Curry Village area under Alternative 2 include construction of integrated utility corridors along the main roadway and utility corridors into proposed facilities in Curry Village. A lift station and electric transformer are also proposed to be constructed in this area. Utility development activities are expected to disturb approximately 11.8 acres of soil, of which 0.3 acre is classified as highly valued soils, 7.4 acres are classified as resilient, and 4.1 acres are classified as other. Repairs to existing utilities in this area would be expected to disturb up to another 2 acres, including 1.2 acres of resilient soils and 0.8 acre of other soils. Construction associated with proposed utility corridors would have local, long-term, negligible to minor, adverse effects on the various soil types.

Removal activities in the Curry Village area include the excavation and removal of the existing water line that follows the existing road alignment. This road is identified for realignment and removal in the Yosemite Valley Plan, and removal of the water line would be coordinated with road removal. The water line removal is expected to affect approximately 4.6 acres; of the 4.6 acres, 1.8 acre is classified as highly valued, 0.9 acre is classified as resilient, and 1.9 acres are classified as other. Although removal of this water line is expected to have local, short-term, negligible to minor adverse effects on soils, it is expected to result in local, long-term, minor, beneficial effects related to restoration of natural hydrologic processes in Stoneman Meadow.

The areas that would be affected are within existing development areas, have been previously disturbed, and are currently proposed for redevelopment. Construction impacts would be similar to those described for the Happy Isles area and would be mitigated through activities described previously in that subsection.

Housekeeping Camp. Proposed utility construction in the Housekeeping Camp area under Alterantive 2 would result in the disturbance of approximately 5.1 acres of soil. Approximately 1.0 acre is classified as highly valued, 1.2 acres are classified as resilient, and 2.9 acres are classified as other. Required repairs to existing sewer lines in this area could disturb another 2.5 acres, of which 2.2 acres contain highly valued soils and 0.3 acre contains resilient soils. Construction of utility corridors and repairs would have local, long-term, negligible to minor, adverse effects on soils.

Utility removals in this area include the excavation and removal of an existing wastewater line that runs to the west from the Housekeeping Camp Lift Station. This removal is expected to affect 1.4 acres of highly valued soils. It is anticipated that this removal would occur along with the proposed removal of structures within the River Protection Overlay in this area.  The removal activities are expected to result in short-term, adverse effects on soils, but are expected to have long-term, beneficial effects associated with restoration of more natural subsurface flow patterns.

The areas that would be affected by this alternative within Housekeeping Camp are within an existing roadway and camping area that have been previously disturbed and developed. Construction impacts would be similar to those discussed under the Happy Isles area above and would be mitigated through mitigation measures discussed in that subsection.

Yosemite Village. Utility corridors proposed in the Yosemite Village area would result in the disturbance of approximately 17.2 acres of soil, including 6.4 acres classified as high valued, 9.5 acres classified as resilient, and 1.3 acres classified as other. Required sewer repairs in the area could impact another 8.7 acres, of which 0.5 acre is classified as highly valued, 6.5 acres are classified as resilient, and 1.7 acres are classified as other. These construction and repair activities would result in local, long-term, moderate, adverse effects to highly valued soils and local, long-term, negligible to minor, adverse effects on other soils. These impacts will occur primarily in areas that have been previously disturbed and can be mitigated through salvage and reuse of highly valued soils for fill and the use of trench plugs, as required, to reduce changes to subsurface flow patterns.

Removal activities proposed in this area include abandonment of existing gravity wastewater collection lines from west Yosemite Village to the existing gravity wastewater line along Northside Drive. These lines are proposed to be pipe burst and abandoned in place. Abandonment of these lines could disturb up to 3.8 acres of soils classified as resilient and 0.1 acre of soils classified as other.  This would have local, short-term, minor, adverse effects but would reduce the potential for future effects in the area related to utility repair and maintenance.

The areas that would be affected are within existing corridors that have been previously disturbed and developed. Construction impacts and mitigation of these impacts would be similar to the discussion above under Happy Isles.

Camp 6/Cook’s Meadow. Construction of proposed utility corridors in the Camp 6/Cook’s Meadow area would disturb approximately 9.2 acres of land in this area, including 7.7 acres of highly valued soils, 0.9 acre of resilient soils, and 0.6 acre of other soils. The areas that would be affected are within existing corridors that have been previously disturbed and developed. This would result in local, long-term, moderate, adverse effects on highly valued soils and negligible effects on other soils. These adverse effects can be mitigated by salvage and reuse of the soils and use of trench plugs, as required, to reduce the potential for changes to subsurface groundwater flow patterns.

If Route Option A is implemented, there would be no change in impact to highly valued soils.

Removal activities in this area would include the removal of the existing exposed wastewater line crossing in Yosemite Creek and the pipe bursting and abandonment of the wastewater lines in Cook’s Meadow west of Residence 1 and through Camp 6. The removal actions in this area could impact up to 8.7 acres of highly valued soils. The removal and abandonment actions would have local, short-term, moderate, adverse effects on highly valued soils, but would result in local, long-term, moderate beneficial effects on these soils through restoration of more natural subsurface water flows through the area.

Impacts to soils in construction and removal areas are expected to be similar to those described for Happy Isles and would be mitigated through use of measures discussed in that section.

Summary of Alternative 2 Impacts

As described under Alternative 1, approximately 407 acres of soil in the Valley are currently affected by some level of previous disturbance. Of this acreage, 120 acres are highly valued resource soils, 217 acres are resilient soils, and the remainder are classified as other. Implementation of Alternative 2 would result in short-term disturbance of up to 216 acres of soils, the vast majority of which have been previously disturbed.

Construction of utility repairs and proposed utility corridors would affect approximately 116 acres of soils, of which approximately 29 acres are highly valued soils, 61 acres are resilient soils, and 2.59 are classified as other soils. These activities under Alternative 2 would result in local, long-term, major, adverse impacts on highly valued soils; local, long-term, moderate, adverse impacts on resilient soils; and local, long-term, moderate, adverse impacts on other soils. These impacts would be mitigated through use of Best Management Practices to minimize spills, soil compaction, and soil erosion; soil salvage and reuse, particularly in highly valued soil areas; and, use of trench plugs where needed to minimize changes to subsurface water flows.  Implementation of these mitigation measures is expected to reduce impacts to soils to a minor level.

Utility removal or abandonment is expected to result in short-term disturbance of approximately 99 acres of soils. Of these, approximately 77 acres are highly valued, 17 acres are resilient, and 5 acres are classified as other. Removal of utilities from environmentally sensitive areas is expected to have local, long-term, major, beneficial effects on highly valued soils, and local, long-term, negligible to minor, beneficial effects on other soils.

Overall, implementation of Alternative 2 is expected to result in local, short-term and long-term, minor, adverse effects on highly valued soils, but local, long-term, major, beneficial effects on these previously disturbed highly valued soils. Effects on other types of soils are expected to be local, minor, and adverse in the short term, and local, negligible to minor, and beneficial in the long term.

Cumulative Impacts

Cumulative impacts to soils are based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley in combination with potential effects of this alternative. The projects identified below include only those projects that could affect soils within Yosemite Valley.

Certain development projects could result in increased degradation of soil resources, such as expansion of campgrounds and construction of lodging and employee housing in Yosemite Valley, as identified in the Yosemite Valley Plan. However, other Yosemite Valley Plan projects related to habitat restoration, such as removal of roads through Stoneman and Ahwahnee Meadows, and the Ecological Restoration of Flood-Damaged Campgrounds, which are designed to restore wet meadow habitat in areas previously developed as campgrounds (discussed earlier in the discussion of impacts), would have long-term, beneficial effects on soils. Although these types of projects may have slight site-specific, short-term, adverse effects (e.g., potential construction erosion and soil loss), the objective of these projects is to restore and manage natural resources and reduce soil degradation. For example, full implementation of the Yosemite Valley Plan would restore approximately 177 acres of soil, of which approximately 136 acres would be highly valued resource soils in Yosemite Valley.

The cumulative projects would result in local, long-term, minor, beneficial cumulative impacts to soil resources. Alternative 2 would enhance the cumulative soil benefits from ecological restoration activities by removing utility infrastructure from the riverbed, riverbanks, and wet meadow areas identified for ecological restoration and allowing natural process to redevelop highly valued soil resources over time.

Impairment

Alternative 2 would result in local, short-term, adverse effects on highly valued soils, but provide for local, long-term,  beneficial effects on highly valued soils related directly to the removal of utilities from highly sensitive areas.  Alterantive 2 would also facilitate the ecological restoration activities proposed in the Yosemite Valley Plan.  This alternative would not impair the soil resources of the park.

Hydrology, Floodplains, and Water Quality

Analysis

Alternative 2 proposes development of integrated utility corridors and removal of utilities within areas identified for ecological restoration. This alternative would result in a reduction in the total length of utility lines in the Valley and in particular, a reduction in the number of river and creek utility crossings, and a reduction in the amount of utility infrastructure within the floodplain. The reduction in utility crossings should allow for more natural river flow, less potential for adverse impacts on park facilities from flood events, and reduced potential for bank erosion and sedimentation from future utility line repairs. Proposed lift stations and electric transformers to be constructed under this alternative would be designed to be submersible and would be placed underground to reduce the potential for adverse effects from flood events.

Impacts to hydrology, floodplains, and water quality associated with Alternative 2 are described by subarea below.

Happy Isles. A new Happy Isles Utility Corridor is proposed within the existing utility and transportation corridor along the west side of the Merced River. Construction activity in this area would result in the temporary loss of vegetation and have the potential to increase soil erosion, which would result in localized, short-term impacts to water quality. The use of heavy equipment presents a potential for accidental releases of fuels or other hazardous substances that could impact local surface water or groundwater quality. The areas that would be excavated to construct the new corridor would be stabilized during construction and returned to the pre-existing grade when the repairs are complete.

A small portion of this area to be crossed by the new utility corridor is located within the floodplain, but this is not expected to adversely affect the area’s ability to accommodate flood flows.

Construction impacts would be mitigated through minimizing the area disturbed, salvaging the existing soils for use as fill, and implementing Best Management Practices during construction to reduce the potential for water quality impacts associated with soil erosion and construction equipment releases. Restoration of the pre-existing grade and revegetation upon completion would minimize the potential for adverse impacts to local hydrologic processes and water quality.

Campgrounds. New integrated utility corridors are proposed along major roadways and through the proposed redeveloped east Valley campground areas. Construction of these corridors would result in short-term construction effects related to loss of vegetation and soil erosion, as described for the Happy Isles area above. In addition, Alternative 2 proposes construction of a new utility corridor crossing of the Merced River at Clark’s Bridge and removal of existing utility crossings from Lower Pines Campground to North Pines Campground. Construction and removal of utility crossings within the Merced River would have short-term, adverse effects on river flow and water quality associated with the temporary diversion of water required during construction and the excavation of the riverbank and riverbed for replacement or removal of the utility line. The use of heavy equipment in the river could result in accidental releases of fuels or other hazardous substances impacting water quality.

Alternative 2 proposes the removal of existing utility infrastructure within the floodplain at North Pines Campground. Although a portion of the proposed Walk-in-Campground Utility Corridor is located in the floodplain, the other proposed utility corridors in this area would be outside the floodplain. These changes are not expected to adversely affect the area’s ability to accommodate flood flows.

Construction impacts would be minimized by limiting work within the river to low water periods, minimizing the disturbance area on the bank and creekbed, salvaging riverbed materials for replacement after construction, returning the riverbed to its pre-existing contour, and implementing Best Management Practices during construction to minimize the potential for water quality impacts associated with accidental spills or soil erosion.

Ecological Restoration Area. Alternative 2 proposes one new utility corridor in the Ecological Restoration area following an existing electric line crossing at the Ahwahnee Bridge. This electric line would be removed from the Merced River, and a consolidated utility corridor (Ahwahnee Bridge Utility Corridor) would be installed. All other utility infrastructure within the flooded campground areas that are designated for ecological restoration would be removed (including four electric transformers), as would four separate Merced River utility crossings between the Ahwahnee and Stoneman Bridges and the two Merced River utility crossings from Housekeeping Camp. These actions would likely have local, short-term, moderate, adverse impacts to river flow and water quality associated with the construction activities onshore and in the riverbed. Alternative 2 would result in a local, long-term, moderate, beneficial impact to river hydrology, water quality, and floodplains due to the reduction in utility river crossings and the removal of utility infrastructure from floodplain areas designated for ecological restoration.

The proposed Ahwahnee Bridge Utility Corridor is proposed within the floodplain, but the utility corridor would be designed and constructed in such a way as to be able to withstand flood damage by placing all of the facilities underground. Construction of this utility corridor would not adversely affect the ability of the floodplain to accommodate flood flows.

Construction impacts would be minimized as discussed under the Campgrounds subsection above.

The Ahwahnee. Alternative 2 proposes construction of a consolidated utility corridor along the Lower Tecoya Housing paved trail and along Ahwahnee Road, as well as a new lift station and associated wastewater utility lines in The Ahwahnee area. Alternative 2 also proposes the removal of existing wastewater and electrical lines that currently cut through Ahwahnee Meadow and areas to the southeast of The Ahwahnee.

The proposed utility corridors in The Ahwahnee area are located predominantly outside the floodplain and would not affect its ability to accommodate flood flows.

Construction impacts to hydrology, floodplains, and water quality would be similar to those discussed for the Happy Isles area. Alternative 2 would result in local, short-term, minor, adverse effects on water quality related to construction activities. Impacts on the floodplain would be negligible. In the long term, Alternative 2 would reduce utility infrastructure in Ahwahnee Meadow and could have long-term, minor, beneficial impacts on hydrology within the meadow.

Curry Village. The utility corridors proposed under Alternative 2 follow an existing road (Southside Drive) or proposed road realignment (Curry Village Utility Corridor). The Curry Village Utility Corridor is expected to be constructed in coordination with the proposed realignment of the road in this area. Alternative 2 also proposes removal of the existing water line that follows the existing road alignment near Curry Village.

Utility corridors and associated infrastructure (lift station and electric transformer) proposed for the Curry Village area in Alternative 2 lie outside of the floodplain and would not affect its ability to accommodate flood flows.

Alternative 2 would result in local, short-term, minor, adverse water quality impacts in the Curry Village area. These construction-related impacts would be minimized and mitigated as described for the Campgrounds area above.

Housekeeping Camp. Alternative 2 proposes construction of utility corridors along Southside Drive and from Southside Drive along the access road into Housekeeping Camp. These facilities, which would include a new lift station and electric transformer within Housekeeping Camp, would be constructed within the floodplain. The utility infrastructure is proposed to be placed underground and be designed to operate while submerged, which should not adversely affect the floodplain’s ability to accommodate flood flows.

Construction impacts associated with proposed activities in this area would include local, short-term, moderate, adverse effects from construction activities; local, long-term, negligible, adverse effects on floodplains; and local, long-term, beneficial effects on river flow and water quality associated with removal of the existing utility river crossings at Housekeeping Camp.

Yosemite Village. Proposed utility improvements under Alternative 2 in the Yosemite Village area include a major utility corridor along Northside Drive, smaller utility reroutes to move wastewater from the Village to a proposed new lift station, and associated infrastructure (lift station and electric transformer).

Portions of the utility corridor and the associated infrastructure would be located within the floodplain. As described above, these facilities would be designed to minimize adverse effects from flood events.

Construction impacts would be similar to those addressed under Housekeeping Camp above. Long-term effects on hydrology, floodplains, and water quality are expected to be negligible.

Camp 6/Cook’s Meadow. This area includes the Merced River crossing of the major utility corridor for the east Valley. Impacts from construction activities in the Merced River would be similar to those discussed for the Merced River crossing in the Campgrounds discussion above. These impacts would include local, short-term, moderate, adverse effects to river flow and water quality associated with the temporary diversion of water required during construction and the excavation of the riverbank and riverbed for construction of the utility corridor. The use of heavy equipment in the river could result in accidental releases of fuels or other hazardous substances.

Alternative 2 would have local, short-term, moderate, adverse effects from construction within the riverbank and -bed. Alternative 2 would also result in local, long-term, minor beneficial effects from pipe bursting of the wastewater utility line that travels completely across Cook’s Meadow and Camp 6. Pipe bursting of this line would result in restoration of more natural subsurface groundwater flows through Cook’s Meadow.

If Route Option A is implemented for the Yosemite Creek Utility Corridor in the Camp 6/Cook’s Meadow area, there would be no change in impacts to hydrology, floodplains, or water quality.

Although facilities in this area would be located within the floodplain, they are proposed to be constructed below ground and would not adversely affect the floodplain’s ability to accommodate flood flows.

Construction impacts would be mitigated as discussed for the Campgrounds area above.  In addition, the park will mitigate water quality and hydrology impacts related to the proposed new Merced River utility crossing by using directional drilling to construct the proposed new Merced River crossing, if found to be technically and economically feasible.

Summary of Alternative 2 Impacts

Alternative 2 proposes development of new integrated utility corridors and removal of utility lines in environmentally sensitive areas. This includes construction of a new integrated utility corridor proposed to cross the Merced River between Housekeeping Camp and Camp 6. Construction of utility repairs and new utility corridors is expected to result in local, short-term, minor to moderate, adverse effects on hydrology and water quality due to disturbance of areas within and adjacent to river- and creekbeds. Alternative 2 would also result in local, long-term, minor, beneficial effects on hydrology and water quality related to the reduced number of facilities within the river- and creekbeds and adjacent sensitive areas. Alternative 2 would have local, long-term, negligible effects on the floodplain.

Cumulative Impacts

Cumulative effects to hydrologic processes, floodplain, and water quality are based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley in combination with potential effects of Alternative 2.

The Merced River has been affected by a variety of projects over time that have introduced obstructions into the river channel, modified the floodplain, and adversely affected water quality. Alterations to hydrology have occurred through development and use within the Merced River corridor since Euro-American settlement. Examples of actions that have had adverse effects on the hydrologic processes of the Merced River include placement of riprap; removal of large woody debris; and construction of bridges, dikes, flood walls, impoundments, dams, and buildings. Conversely, more recent actions such as riverbank restoration projects, removal of impoundments and bridges, and limiting visitor use to particular areas help restore the natural river flow and reduce bank erosion.

Reasonably foreseeable future projects that would have beneficial impacts on hydrologic processes and water quality include restoration actions identified in the Yosemite Valley Plan. Elements of the Yosemite Valley Plan include removal of Sugar Pine Bridge, which constrains flows of the Merced River, rehabilitation of the Lower Yosemite Fall corridor, restoration of campgrounds within the floodplain to natural meadow conditions, and removal of facilities from the 100-year floodplain. Alternatively, construction of additional lodging, campsites, and a visitor transit center in the east Valley could have adverse impacts on hydrology, floodplains, and water quality. Overall, the effect of implementing projects identified in the Yosemite Valley Plan would have a long-term, beneficial effect on river hydrologic processes, floodplains, and water quality.

The Merced River Plan protects river-related natural resources through the application of management elements, including the River Protection Overlay, management zoning, protection and enhancement of Outstandingly Remarkable Values, Section 7 determination process, and implementation of a Visitor Experience Resource Protection framework (see Chapter V, Merced Wild and Scenic River). Implementation of the Merced River Plan is expected to have long-term, beneficial effects on hydrology, floodplains, and water quality in the Merced River corridor.

Cumulatively, the following proposed projects are anticipated to have beneficial impacts on hydrologic processes and water quality of the Merced River: The Lower Yosemite Fall Project, Cascades Dam Removal, Happy Isles Dam Removal, Happy Isles to Vernal Falls Trail Reconstruction, and the Eagle Creek Merced River Ecological Restoration (Yosemite Valley).

While some of the past, present, and reasonably foreseeable future projects along the Merced River in Yosemite Valley would ultimately remove constrictions to streamflows, enhance water quality, rehabilitate eroded streambanks, and reduce degradation of stream characteristics in the Merced River, others would result in adverse water quality impacts and bank erosion. Thus, the cumulative projects would result in a local, long-term, minor, beneficial impact to hydrologic processes and water quality. Alternative 2 would enhance this beneficial impact to some degree by removing existing utility infrastructure from within the floodplains, riverbanks, and ecological restoration areas, thus resulting in the potential for long-term, minor, beneficial impacts to hydrologic processes, floodplains, and water quality in Yosemite Valley.

Impairment

Alternative 2 would result in local, short-term, minor to moderate, adverse effects to hydrologic processes and water quality associated with construction and removal actions proposed under this alternative. Alternative 2 would have local, long-term, minor, beneficial effects on the free flow of the Merced River due to reduced utility infrastructure within the river and the floodplain. Since adverse effects are expected to be short-term, minor to moderate, and localized, Alternative 2 would not impair the hydrologic resources of Yosemite Valley.

Wetlands

Analysis

Alternative 2 would result in short-term, adverse effects on wetland and aquatic habitats in Yosemite Valley due to construction activities; however, most of the areas proposed for utility corridor construction have been previously disturbed by utilities, transportation facilities, or other development. Implementation of Alternative 2 would remove utility infrastructure in sensitive wetland areas proposed for ecological restoration in the Yosemite Valley Plan, and allow for the restoration of more natural subsurface water flows through the wetland areas and between the wetlands and the river.  Impacts associated with Alternative 2 are summarized in table IV-8 and described by subarea below.

Happy Isles. In the Happy Isles area, there are no wetland or aquatic habitats within the areas to be affected by construction activities. Therefore, there would be no direct impacts to wetland or aquatic habitats in this area. Indirect impacts to wetland or aquatic habitats in the immediate vicinity of construction activities (e.g., the Merced River) may include the addition of silt and the introduction of pollutants (i.e., fuels or lubricants). The application of mitigation measures described in Chapter II, specifically those related to stormwater management measures and spill prevention and pollutant control, would reduce the localized, short-term, adverse, construction-related impacts to wetland and aquatic habitats in the Happy Isles area to a negligible intensity.

Campgrounds. There would be no permanent reduction in the size of wetland and aquatic habitats in the Campgrounds area related to implementation of Alternative 2. Wetland habitats that may be affected in the Campgrounds area are predominately associated with the Merced River as well as several creeks that cross through the area. The areas that would be disturbed are within and adjacent to existing utility corridors that have been previously disturbed, are currently developed as campground areas, and are proposed for redevelopment. Construction impacts to wetland and aquatic habitats would be related to heavy equipment and construction activities and could include soil disturbance and compaction, dust, vegetation removal, root damage, erosion, and introduction and spread of non-native species. The addition of silt, the resuspension of sediment, or the introduction of pollutants (i.e., fuels or lubricants) related to construction activities could degrade the quality of native wetland and aquatic habitats in the immediate vicinity of construction activities.

Wetland and Aquatic Habitats Potentially Affected by Alternative 2

 

^{a   Includes repairs to existing wastewater lines as described in Alternative 1, as well as construction of proposed consolidated utility corridors.}

Construction of the integrated utility corridors and repairs to existing utilities within the Campgrounds area are expected to have localized, short-term, minor, adverse impacts to 1.00 acre of wetland and aquatic habitats, which include riverine upper perennial, palustrine forest, palustrine scrub shrub, and palustrine emergent. Construction activities may also have localized, long-term, minor, adverse impacts on palustrine forest wetland habitat if the removal of trees are necessary within these areas. These short-term and long-term impacts can be mitigated using mitigation measures discussed below. The construction of and continued presence of utility infrastructure within wetland and aquatic habitats in the Campgrounds area could have long-term, minor, adverse effects on the hydrology of these habitats by impeding the natural subsurface water flows within wetland areas and between the river and adjacent wetlands.

Utility removals would affect approximately 2.04 acres, which include riverine upper perennial, palustrine forest, palustrine scrub shrub, and palustrine emergent. The removal of utilities in the Campgrounds area is planned to coincide with other ecological restoration activities in the former campground areas, identified in the Yosemite Valley Plan.  The proposed utility removals are expected to have long-term beneficial effects on wetland and aquatic habitats by restoring more natural subsurface water flows throughout the wetlands and between the wetlands and the river. Thus, removal activities are expected to result in localized, short-term, minor, adverse effects on wetland and aquatic habitats in removal areas, but are expected to have local, long-term, moderate, beneficial effects on wetland and aquatic habitats in these areas. Removal activities may also have localized, long-term, minor, adverse impacts on palustrine forest wetland habitat due to the potential for a limited loss of trees within the areas.

The application of mitigation measures described in Chapter II, specifically those related to protection of wetland areas, minimization of disturbance areas, stormwater management measures, and spill prevention and pollutant control would reduce the local, short and long-term, adverse impacts to wetland and aquatic habitats to a minor intensity.

Ecological Restoration Area. There would be no permanent reduction in the size of wetland and aquatic habitats in the Ecological Restoration area related to implementation of Alternative 2. Wetland habitats that may be affected in the Ecological Restoration area are predominately associated with the Merced River corridor. The areas that would be affected are within existing corridors that have been previously disturbed and developed as campgrounds, but which are currently identified for ecological restoration in the Yosemite Valley Plan. Effects to wetland and aquatic habitats related to construction activities would be similar to those discussed for the Campgrounds area. Construction impacts would be mitigated as described for the Campgrounds area above.

Construction of the Ahwahnee Bridge Utility Corridor is expected to have localized, short-term, minor, adverse, construction-related impacts to 0.70 acre of wetland and aquatic habitats, which includes riverine upper perennial, palustrine forest, and palustrine emergent. Construction activities may also have localized, long-term, adverse impacts on palustrine forest wetland habitat if the removal of trees is necessary within this area. These short-term and long-term impacts can be mitigated to a minor level using mitigation measures as discussed for the Campgrounds area. The construction of and the continued presence of utility infrastructure within wetland and aquatic habitats could have local, long-term, minor, adverse effects on the hydrology of these habitats by impeding the natural subsurface water flows within wetland areas and between the river and adjacent wetlands.

Utility removals would affect approximately 7.85 acres of wetland and aquatic habitats, which include riverine upper perennial, palustrine forest, and palustrine emergent. Removal activities in this area would be coordinated with ecological restoration plans, which propose removal of fill and restoration of natural conditions in these areas. These removals are expected to have local, short-term, minor to moderate, adverse effects on wetland and aquatic habitats, but are expected to result in local, long-term, minor benefits to wetland and aquatic habitats from restoration of natural hydrologic and biological processes. Removal activities may also have localized, long-term, minor, adverse impacts on palustrine forest wetland habitat due to the potential for a limited loss of trees within the areas.

The Ahwahnee. There would be no permanent reduction in the size of wetland and aquatic habitats in The Ahwahnee area related to construction or removal and abandonment activities. The areas that would be affected are within existing corridors that have been previously disturbed and developed. Construction of the integrated utility corridor is expected to have localized, short-term, minor, adverse, construction-related impacts to 1.03 acres of palustrine emergent wetland habitat. The wetland habitat potentially impacted in The Ahwahnee area is associated with the Ahwahnee meadow. These impacts can be mitigated to a minor intensity using mitigation measures as discussed for the Campgrounds area. The construction of and the continued presence of utility infrastructure within wetland and aquatic habitats could have long-term, minor, adverse effects on the hydrology of these habitats by impeding the natural subsurface water flows within wetland areas and between the river and adjacent wetlands.

In The Ahwahnee area, 7.33 acres of palustrine emergent wetland habitat would be affected by pipe bursting and abandonment activities. This would have localized, short-term, minor to moderate, adverse effects to wetlands and would result in local, long-term, minor beneficial effects to the wetland related to the elimination of future utility repair and maintenance activities in the area.

Construction impacts and mitigation of these impacts would be similar to the discussion above under Campgrounds.

Curry Village. There would be no permanent reduction in the size of wetland and aquatic habitats in the Curry Village area related to implementation of Altenative 2. The areas that would be affected are within existing development areas, have been previously disturbed, and are currently proposed for redevelopment. Effects to wetland and aquatic habitats related to construction activities would be similar to those discussed for the Campgrounds area. Construction of the proposed utility corridors and repairs to existing utilities within the area are expected to have localized, short-term, minor, adverse, construction-related impacts to 0.14 acre of wetland habitat, which includes palustrine forest and palustrine emergent. Construction activities may also have localized, long-term, negligible to minor, adverse impacts on palustrine forest wetland habitat due to the potential for a limited loss of trees within the area. These short-term and long-term impacts can be mitigated to a negligible to minor intensity using mitigation measures as discussed for the Campgrounds area. The construction of and the continued presence of utility infrastructure within wetland and aquatic habitats could have long-term, minor, adverse effects on the hydrology of these habitats by impeding the natural subsurface water flows within wetland areas and between the river and adjacent wetlands.

The removal of the existing water line would affect approximately 1.08 acres of wetland habitat, which includes palustrine forest and palustrine emergent. Although removal activities are expected to have local, short-term, minor, adverse effects on wetland and aquatic habitats, they are expected to result in local, long-term, minor, beneficial effects related to restoration of natural hydrologic processes in Stoneman Meadow. Removal activities may also have localized, long-term, minor, adverse impacts on palustrine forest wetland habitat due to the potential for a limited loss of trees within the area.

Construction impacts would be mitigated as described for the Campgrounds area above.

Housekeeping Camp. There would be no permanent reduction in the size of wetland and aquatic habitats in the Housekeeping Camp area related to construction or removal activities. The areas that would be affected are within an existing roadway and camping area that have been previously disturbed and developed. Effects to wetland and aquatic habitats related to construction activities would be similar to those discussed for the Campgrounds area. Construction of the integrated utility corridor and existing utility repairs are expected to have localized, short-term, adverse, construction-related impacts to 0.20 acre of wetland and aquatic habitats, which includes riverine upper perennial and palustrine emergent. These can be mitigated to a negligible to minor intensity using mitigation measures as discussed for the Campgrounds area. The construction of and the continued presence of utility infrastructure within wetland and aquatic habitats could have long-term, minor, adverse effects on the hydrology of these habitats by impeding the natural subsurface water flows within wetland areas and between the river and adjacent wetlands.

In the Housekeeping Camp area, there are no wetland or aquatic habitats present within the areas to be affected by the proposed utility removal. Therefore, direct impacts to wetland or aquatic habitats are not anticipated. Indirect impacts to wetland or aquatic habitats in the vicinity of removal activities (e.g., the Merced River) would be similar to those discussed under Happy Isles. The application of mitigation measures discussed above for the Happy Isles area would reduce localized, short-term, adverse, construction-related impacts to wetland and aquatic habitats to a negligible intensity.

Construction impacts would be mitigated as described for the Campgrounds area above.

Yosemite Village. There would be no permanent reduction in the size of wetland and aquatic habitats in the Yosemite Village area related to construction or removal and abandonment activities. The areas that would be affected are within existing corridors that have been previously disturbed and developed. Construction of the integrated utility corridor is expected to have localized, short-term, adverse, construction-related impacts to 0.99 acre of palustrine emergent wetland habitat. The wetland habitat potentially impacted in the Yosemite Village area is located within a narrow band along Northside Drive. These impacts can be mitigated to a negligible to minor intensity using mitigation measures as discussed for the Campgrounds area. The construction of and the continued presence of utility infrastructure within wetland and aquatic habitats could have long-term, minor, adverse effects on the hydrology of these habitats by impeding the natural subsurface water flows within wetland areas and between the river and adjacent wetlands.

In the Yosemite Village area, less than 0.01 acre of palustrine emergent wetland habitat would be affected by pipe bursting and abandonment activities. This would have localized, short-term, negligible, adverse effects to wetlands and would result in local, long-term, minor beneficial effects to the wetland related to the elimination of future utility repair and maintenance activities in the area.

Construction impacts and mitigation of these impacts would be similar to the discussion above under Campgrounds.

Camp 6/Cook’s Meadow. There would be no permanent reduction in the size of wetland and aquatic habitats in the Camp 6/Cook's Meadow area related to construction or removal activities. The areas that would be affected are within existing corridors that have been previously disturbed and developed. Effects to wetland and aquatic habitats related to construction activities would be similar to those discussed for the Campgrounds area. Construction of the Merced River Crossing Utility Corridor is expected to have localized, short-term, adverse, construction-related impacts to 1.82 acres of wetland and aquatic habitats, which include riverine upper perennial, palustrine forest, and palustrine emergent. Construction activities may also have localized, long-term, adverse impacts on palustrine forest wetland habitat if the removal of trees are necessary within these areas. These short-term and long-term impacts can be mitigated to a minor level using mitigation measures as discussed for the Campgrounds area. The construction of and the continued presence of utility infrastructure within wetland and aquatic habitats could have long-term, minor, adverse effects on the hydrology of these habitats by impeding the natural subsurface water flows within wetland areas and between the river and adjacent wetlands.

If Route Option A is implemented, there would be slightly less emergent wetland habitat affected by construction in the Camp 6/Cook’s Meadow area.  Route Option A would not result in a substantial change to the overall level of impacts to wetland resources in this area. 

In the Camp 6/Cook's Meadow area, approximately 1.82 acres of wetland and aquatic habitats, including riverine upper perennial, palustrine forest, and palustrine emergent, would be affected by utility pipe bursting and abandonment activities. These activities are expected to have localized, short-term, minor, adverse effects on wetland and aquatic habitats, but are expected to result in local, long-term, minor benefits to wetland and aquatic habitats through restoration of more natural subsurface water flows through the Cook’s Meadow area. Removal activities may also have localized, long-term, minor, adverse impacts on palustrine forest wetland habitat due to the potential for a limited loss of trees within the areas.

Construction impacts would be mitigated as described for the Campgrounds area above.

Summary of Alternative 2 Impacts

There would be no permanent reduction in the size of wetland and aquatic habitats related to construction or removal activities associated with Alternative 2. Under Alternative 2, construction of integrated utility corridors and existing utility repairs are expected to have localized, short-term, adverse, construction-related impacts to 5.88 acres of wetland and aquatic habitats. Removal and abandonment activities are expected to have localized, short-term, adverse, construction-related impacts to 20.12 acres of wetland and aquatic habitats.  These removals are expected to have localized, long-term, minor, beneficial effects related to the restoration of more natural subsurface water flows. With the exception of the Merced River Crossing Utility Corridor, the areas that would be affected are within existing corridors that have been previously disturbed and developed.

The combined impact to wetland resources over the entire project area may result in short-term impacts of minor to moderate intensity. The construction of and the continued presence of utility infrastructure within wetland and aquatic habitats could have long-term, minor, adverse effects on the hydrology of these habitats by impeding the natural subsurface water flows within wetland areas and between the river and adjacent wetlands. Construction activities may also have localized, long-term, minor, adverse impacts on palustrine forest wetland habitat if the removal of trees are necessary within these areas.

Construction impacts would be mitigated through the application of mitigation measures described in Chapter II, specifically those related to protection of wetland areas, minimization of disturbance areas, and prevention of spills. Consolidation of utility infrastructure in major developed corridors, removal of utilities from environmentally sensitive areas, and restoration of more natural subsurface water flows in wetland areas are expected to have local, long-term, minor to moderate, beneficial effects on wetland resources.

Cumulative Impacts

Cumulative effects to wetland and aquatic resources are based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley in combination with potential effects of this alternative. The projects identified below include those projects that have the potential to affect local wetland patterns.

Wetland and riparian systems of the Merced River corridor have been substantially altered by development and visitor activities. These changes have negatively influenced the size, form, and function of wetlands and the plants, wildlife, and aquatic species that inhabit them. Cumulative effects would be mixed, combining both adverse and beneficial effects. Cumulative beneficial effects on wetlands would include wetland restoration, rehabilitation projects, and ecosystem management. Cumulative adverse effects would be related to increased facilities, regional growth, and visitor demand.

Reasonably foreseeable future actions within Yosemite Valley are considered to have an overall beneficial effect on wetlands. For example, the Merced River Plan protects river-related natural resources through the application of management elements, including the River Protection Overlay, management zoning, protection and enhancement of Outstandingly Remarkable Values, and implementation of a Visitor Experience Resource Protection framework (refer to Chapter V, Merced Wild and Scenic River).

Full implementation of the Yosemite Valley Plan would result in a net gain of 118 acres of wetlands in Yosemite Valley through actions such as restoration of the former Upper River Campground and a portion of Lower Pines Campground to natural conditions; removal of roads through Stoneman and Ahwahnee Meadow; and removal of other bridges (i.e., Sugar Pine and possibly Stoneman) affecting the natural flow of the Merced River. Farther downstream, removal of the Cascades Diversion Dam would remove an unnatural constriction to the free flow of the Merced River, thereby enhancing natural river dynamics including wetlands and aquatic systems below Yosemite Valley. Some Yosemite Valley Plan projects, such as construction of a replacement footbridge at the Happy Isles area, construction of a vehicle bridge across Yosemite Creek near Yosemite Lodge, and expansion of some campgrounds in the east Valley, have the potential to adversely affect local wetlands. These projects would be designed to ensure the long-term protection of wetlands consistent with the Merced River Plan, the Clean Water Act, and Executive Order 11990: Protection of Wetlands.

Cumulative actions would have a local, long-term, moderate, beneficial cumulative effect on wetlands within Yosemite Valley due to wetland restoration efforts. Over the long term, Alternative 2 would enhance the cumulative benefits from ecological restoration activities by removing utility infrastructure from the riverbed, riverbanks, and wet meadow areas identified for ecological restoration.

Impairment

Alternative 2 would result in local, short-term, minor, adverse effects on wetlands and aquatic resources from construction activities and local, long-term, minor to moderate, beneficial effects on wetland and aquatic resources due to the removal of utilities from highly sensitive areas and the restoration of more natural subsurface water flow patterns in those areas. This alternative would not impair the wetland and aquatic resources of the park.

Vegetation

Analysis

Alternative 2 would result in short-term, adverse effects on vegetation in Yosemite Valley due to construction activities; however, most of the areas proposed for utility corridor construction have been previously disturbed by utilities, transportation facilities, or other development. Implementation of Alternative 2 would remove utility infrastructure in areas where ecological restoration is proposed, facilitating the ecological restoration proposed in the Yosemite Valley Plan.

Impacts associated with Alternative 2 are summarized in table IV-9 and area described by subarea below.

Vegetation Community Types Potentially Affected by Alternative 2

 

^{a   Includes repairs to existing wastewater lines as described in Alternative 1, as well as construction of proposed consolidated utility corridors.}

Happy Isles. Construction activities related to the proposed Happy Isles Utility Corridor and existing utility repairs would result in the disturbance and localized removal of vegetation over approximately 7.5 acres, which include 0.5 acre of riparian, a highly valued resource. The area proposed to be affected is within and adjacent to an existing water utility corridor and park operations access stock trail. The vegetation or cover types that would be affected by the localized removal of vegetation include mixed riparian-conifer corridor forest, developed ponderosa pine forest, white fir-Douglas fir forest, and developed open area-sparse vegetation. Construction-related activities planned in this area would have short-term and potentially long-term, minor to moderate, adverse effects to vegetation, due to the limited localized loss of mature trees. Effects would be related to heavy equipment and construction activities. Effects could include soil disturbance and compaction, dust generation, vegetation removal, root damage, erosion, introduction and spread of non-native species, and spread of annosus root disease. The addition of pollutants (i.e., fuels or lubricants) related to construction activities could degrade the quality of native vegetation. Localized, long-term, minor loss of vegetation due to routine clearance of vegetation at utility access manholes may also occur as a result of Alternative 2.

The application of mitigation measures described in Chapter II, particularly those designed to address revegetation, minimization of disturbance areas and loss of mature trees, non-native species, and annosus root disease, would reduce these potential local, long-term and short-term, adverse impacts to vegetation to a minor intensity.

Campgrounds. Construction activities related to the proposed utility corridors and existing utility repairs in the Campgrounds area would result in the disturbance and localized removal of vegetation over approximately 34.4 acres, which include 0.1 acre of meadow, 8.1 acres of riparian, and 0.1 acre of oak, all highly valued resources. The areas that would be disturbed are within and adjacent to existing utility corridors that have been previously disturbed, are currently developed as campground areas, and are proposed for redevelopment. The vegetation or cover types that would be affected by the localized removal of vegetation include Carex senta wet meadow border, fen, oxbow and cutoff channels, white alder riparian forest, mixed riparian-conifer corridor forest, impacted mixed riparian-conifer corridor forest, open ponderosa pine-California black oak woodland, developed open ponderosa pine-California black oak woodland, ponderosa pine forest, developed ponderosa pine forest, sparse ponderosa pine scrub, dense mixed coniferous forest, and river. Construction and removal activities planned in this area would have short-term and potentially long-term, minor to moderate, adverse effects to vegetation, due to the limited loss of mature trees. Localized, long-term, minor loss of vegetation due to routine clearance of vegetation at utility access manholes may also occur as a result of Alternative 2.

Removal of utilities would affect approximately 19.6 acres, which include 5.3 acres of riparian, a highly valued resource. Removal of utilities in the Campgrounds area is planned to coincide with other ecological restoration activities in the former campground areas. Removal of utilities in the Campgrounds area would result in local, short-term, minor, adverse effects from removal activities, but would also result in local, long-term, minor beneficial effects from removal of utilities and restoration of more natural subsurface hyrologic processes in riparian areas.

The application of mitigation measures as described above for the Happy Isles area would reduce these local, short-term and long-term, adverse impacts to vegetation to a minor intensity.

Ecological Restoration Area. Construction activities related to the proposed Ahwahnee Bridge Utility Corridor through the Ecological Restoration area would result in the disturbance and localized removal of vegetation over approximately 6.4 acres, which include 0.6 acre of riparian, a highly valued resource. The areas that would be affected are within existing corridors that have been previously disturbed and developed for campground utilities, but which are currently identified for ecological restoration in the Yosemite Valley Plan. The vegetation or cover types that would be affected by the localized removal of vegetation include bunch-grass meadow, Carex vesicaria wet meadow, grass-sedge meadow, grass meadow, dense black cottonwood-willow riparian forest, oxbow and cutoff channels, sandbar willow riparian woodland, impacted mixed riparian-conifer corridor forest, California black oak woodland with encroaching conifers, open ponderosa pine-California black oak woodland, developed open ponderosa pine-California black oak woodland, ponderosa pine forest, developed ponderosa pine forest, dense mixed coniferous forest, river, and bare. Construction and removal activities planned in this area would have short-term and potentially long-term, minor, adverse effects to vegetation due to the limited localized loss of mature trees. Localized, long-term, minor loss of vegetation due to routine clearance of vegetation at utility access manholes may also occur as a result of Alternative 2.

Utilities would be removed and natural areas restored over approximately 44.7 acres, which include 5.4 acres of meadow, 2.6 acres of riparian, and 1.3 acres of oak, all highly valued resources. Removal activities in this area would be coordinated with ecological restoration plans, which propose removal of fill and restoration of natural conditions in these areas. Although the utility removals would have local, short-term, minor, adverse effects on vegetation,  removal of utilities and restoration of more natural subsurface hyrologic processes in riparian and meadow areas are expected to result in local, long-term, minor, beneficial effects to native vegetation.

Effects to vegetation related to construction and removal activities would be similar to those discussed for the Happy Isles area. The application of mitigation measures as described above for the Happy Isles area would reduce these local, short-term and long-term, adverse construction-related impacts to vegetation to a minor intensity.

The Ahwahnee. Construction activities related to the proposed Ahwahnee Road Utility Corridor and existing utility repairs would result in the disturbance and localized removal of vegetation over approximately 11.3 acres, which include 2.6 acres of meadow, 0.2 acre of riparian, and 1.3 acres of oak, all highly valued resources. The areas that would be affected are within existing corridors that have been previously disturbed and developed. Effects to vegetation related to construction activities would be similar to those discussed for the Happy Isles area. The vegetation or cover types that would be affected by the localized removal of vegetation include bracken fern meadow, bunch-grass meadow, Carex senta wet meadow border, grass-sedge meadow, grass meadow, mixed low meadow, muhlenbergia meadow, impacted mixed riparian-conifer corridor forest, California black oak woodland, canyon live oak, open ponderosa pine-California black oak woodland, developed open ponderosa pine-California black oak woodland, ponderosa pine forest, developed ponderosa pine forest, sparse ponderosa pine scrub, dense mixed coniferous forest, river, developed open area-sparse vegetation, watered lawn, and bare. Construction activities planned in The Ahwahnee area would have short-term and potentially long-term, minor, adverse effects to vegetation due to the limited localized loss of mature trees. Localized, long-term, minor loss of vegetation due to routine clearance of vegetation at utility access manholes may also occur as a result of Alternative 2.

Pipe bursting and utility line removal activities would occur over approximately 16.6 acres, which include 7.3 acres of meadow and 0.7 acre of oak, both highly valued resources. Pipe bursting and removal of utilities in The Ahwahnee area would result in local, short-term, adverse effects but are expected to also result in local, long-term, minor, beneficial effects associated with the restoration of more natural subsurface water flows in the meadow areas. The application of mitigation measures as described above for the Happy Isles area would reduce local, short-term and long-term, adverse construction-related impacts to vegetation to a minor intensity.

Curry Village. Construction activities related to proposed utility corridors and existing utility repairs would result in the disturbance and localized removal of vegetation over approximately 13.8 acres, which include 0.1 acre of riparian and 2.2 acres of oak, both highly valued resources. The areas that would be affected are within existing development areas, have been previously disturbed, and are currently proposed for redevelopment. Effects to vegetation related to construction and removal activities would be similar to those discussed for the Happy Isles area. The vegetation or cover types that would be affected by the localized removal of vegetation include Carex senta wet meadow border, grass-sedge meadow, mixed low meadow, montane-alpine riparian scrub, oxbow and cutoff channels, California black oak woodland with encroaching conifers, ponderosa pine forest, developed ponderosa pine forest, dense mixed coniferous forest, developed open area-sparse vegetation, watered lawn, and bare. Construction and activities planned in this area would have short-term and potentially long-term, adverse effects to vegetation due to the limited localized loss of mature trees. Localized, long-term, minor loss of vegetation due to routine clearance of vegetation at utility access manholes may also occur as a result of Alternative 2.

Utility removals would affect approximately 4.6 acres, which include 1.9 acres of meadow, 0.3 acre of riparian, and 0.4 acre of oak, all highly valued resources. Removal of utilities in the Curry Village area would result in local, short-term, minor, adverse effects on vegetation, but would also result in long-term, minor, beneficial effects on meadow areasfrom restoration of more natural subsurface hydrologic processes.

The application of mitigation measures as described above for the Happy Isles area would reduce these local, short-term and long-term, adverse construction-related impacts to vegetation to a minor intensity.

Housekeeping Camp. Construction activities related to proposed utility corridors and existing utility repairs would result in the disturbance and localized removal of vegetation over approximately 7.6 acres, which include 0.1 acre of riparian, a highly valued resource. The areas that would be affected are within existing utility and transportation corridors and campground areas that have been previously disturbed and developed. Effects to vegetation related to construction and removal activities would be similar to those discussed for the Happy Isles area. The vegetation or cover types that would be affected by the localized removal of vegetation include impacted mixed riparian-conifer corridor forest, developed open ponderosa pine-California black oak woodland, dense mixed coniferous forest, white fir-Douglas fir forest, and river. However, California black oak, a highly valued resource, may be adversely affected by construction activities when present within mixed conifer vegetation communities. Construction activities planned in this area would have short-term and potentially long-term, minor to moderate, adverse effects to vegetation depending on the type of vegetation (e.g., tree, shrub, or herbaceous) and number, size, and species of trees removed. Localized, long-term, minor loss of vegetation due to routine clearance of vegetation at utility access manholes may occur as a result of Alternative 2.

Removal of utilities within the Housekeeping Camp area would occur over approximately 1.4 acres and would not be anticipated to affect highly valued resources. Removal of utilities in the Housekeeping area would result in local, short-term, minor, adverse effects on vegetation, but also local, long-term, minor beneficial effects associated with restoration of more natural subsurface hydrologic processes in the riparian area.

The application of mitigation measures as described above for the Happy Isles area would reduce these local, short-term and long-term, adverse construction-related impacts to vegetation to a minor intensity.

Yosemite Village. Construction activities related to proposed utility corridors and existing utility repairs would result in the disturbance and localized removal of vegetation over approximately 25.9 acres, which include 2.8 acres of meadow, 0.2 acre of riparian, and 9.4 acres of oak, all highly valued resources. The areas that would be affected are within existing corridors that have been previously disturbed and developed. Effects to vegetation related to construction activities would be similar to those discussed for the Happy Isles area. Construction and removal activities planned in this area would have short-term and potentially long-term, minor to moderate, adverse effects to vegetation depending on the type of vegetation (e.g., tree, shrub, or herbaceous) and number, size, and species of trees removed. The vegetation or cover types that would be affected by the localized removal of vegetation include bracken fern meadow, Carex senta wet meadow border, Carex vesicaria wet meadow, grass-sedge meadow, grass meadow, oxbow and cutoff channels, white alder riparian forest, California black oak woodland, developed California black oak woodland, open ponderosa pine-California black oak woodland, developed open ponderosa pine-California black oak woodland, ponderosa pine forest, developed ponderosa pine forest, dense mixed coniferous forest, apple orchard, developed open area-sparse vegetation, watered lawn, and bare. Localized, long-term, minor loss of vegetation due to routine clearance of vegetation at access manholes and access points adjacent to road corridors may occur as a result of Alternative 2.

Pipe bursting and abandonment of utilities within the Yosemite Village area would occur over approximately 3.9 acres, which include 0.2 acre of meadow and 2.3 acres of oak, both highly valued resources. Pipe bursting and abandonment in the Yosemite Village area would reduce the potential for future effects in the area related to utility repair and maintenance and would have local, short-term, minor, adverse effects, but local, long-term, negligible to minor, beneficial effects in the riparian and meadow areas from a reduction in future disturbance for utility maintenance.

The application of mitigation measures as described above for the Happy Isles area would reduce these local, short-term and long-term, adverse construction-related impacts to vegetation to a minor intensity.

Camp 6/Cook’s Meadow. Construction activities related to the proposed Merced River Utility Corridor would result in the disturbance and localized removal of vegetation over approximately 9.2 acres, which include 0.8 acre of meadow and 2.6 acres of riparian, both highly valued resources. With the exception of the Merced River Crossing Utility Corridor, the areas that would be affected are within existing corridors that have been previously disturbed and developed. Effects to vegetation related to construction and removal/abandonment activities would be similar to those discussed for the Happy Isles area. The vegetation or cover types that would be affected by the localized removal of vegetation include Carex senta wet meadow border, Carex vesicaria wet meadow, grass-sedge meadow, grass meadow, dense black cottonwood-willow riparian forest, oxbow and cutoff channels, mixed riparian-conifer corridor forest, impacted mixed riparian-conifer corridor forest, California black oak woodland, open ponderosa pine-California black oak woodland, developed open ponderosa pine-California black oak woodland, ponderosa pine forest, dense mixed coniferous forest, white fir-Douglas fir forest, river, developed open area-sparse vegetation, and bare. Construction activities planned in this area would have short-term and potentially long-term, minor to moderate, adverse effects to vegetation depending on the type of vegetation (e.g., tree, shrub, or herbaceous) and number, size, and species of trees removed. Localized, long-term, minor loss of vegetation due to routine clearance of vegetation at access manholes and access points adjacent to road corridors may occur as a result of Alternative 2.

Route Option A would not result in a change to the overall impacts to vegetation resources in the Camp 6/Cook’s Meadow area. However, if Route Option A is implemented, there would be more acreage of meadow and oak vegetation communities and less acreage of riparian vegetation community affected by Alternative 2. However, acreages of vegetation communities are based upon vegetation mapping performed by NPS in 1994 (NPS 1994b) and reconnaissance-level field surveys performed in 2003 found that fewer well developed oak trees would be affected by Route Option A, and most of this route segment crosses an open transitional area between meadow and oak woodland vegetation.

Removal and abandonment of utilities within the Camp 6/Cook's Meadow area would occur over approximately 8.7 acres, which include 1.6 acres of meadow, 2.2 acres of riparian, and 0.5 acre of oak, all highly valued resources. Utility abandonment actions in the Camp 6/Cook's Meadow area would have local, short-term, minor, adverse effects to vegetation, but are also expected to result in local, long-term, minor to moderate, beneficial effects on meadow and riparian areas through restoration of more natural subsurface water flows through Cook’s Meadow and riparian areas.

The application of mitigation measures as described above for the Happy Isles area would reduce these local, short-term and long-term, adverse construction-related impacts to vegetation to a minor intensity.

Summary of Alternative 2 Impacts

Under Alternative 2, construction of integrated utility corridors and existing utility repairs are expected to have localized, short-term and potentially long-term, minor to moderate, adverse, construction-related impacts to approximately 116 acres of vegetation, which include 6.3 acres of meadow, 12.4 acres of riparian, and 13.6 acres of oak, all highly valued resources. Removal and abandonment activities are expected to have localized, short-term, minor, adverse effects but local, long-term, minor, beneficial effects on approximately 99.5 acres of vegetation, which include 16.4 acres of meadow, 10.4 acres of riparian, and 5.2 acres of oak, all highly valued resources. The potential for long-term, adverse effects to vegetation depend upon the type of vegetation (e.g., tree, shrub, or herbaceous) and number, size, and species of trees removed. The areas that would be affected are predominately within existing corridors that have previously been disturbed and developed, with the exception of the Merced River Crossing Utility Corridor. Vegetation impacts over the project area are expected to be localized, short-term and potentially long-term, minor, and adverse.

Construction impacts would be mitigated through the application of mitigation measures described in Chapter II, which call for minimizing the area disturbed, revegetation, preventing the spread of invasive and non-native species, and preventing the spread of annosus root disease. Consolidation of utility infrastructure in major developed corridors, removal of utilities from environmentally sensitive areas, and restoration of more natural subsurface water flows are expected to have local, long-term, minor to moderate, beneficial effects on meadow and riparian resources.

Cumulative Impacts

Cumulative effects to vegetation are based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley in combination with potential effects of this alternative. The projects identified below include those projects that have the potential to affect local vegetation patterns.

Vegetation in Yosemite Valley has been substantially altered by development and visitor activities. These changes have negatively influenced the size, form, and function of vegetation communities and the plants and wildlife that inhabit them. Cumulative effects from future actions would be mixed, combining both adverse and beneficial effects. Cumulative beneficial effects on vegetation include restoration, rehabilitation projects, and ecosystem management. Cumulative adverse effects would be related to increased facilities and visitor demand.

Reasonably foreseeable future actions within Yosemite Valley are considered to have an overall net benefit to vegetation. For example, the Merced River Plan protects river-related natural resources through the application of management elements, including the River Protection Overlay, management zoning, protection and enhancement of Outstandingly Remarkable Values, and implementation of a Visitor Experience Resource Protection framework.

Full implementation of the Yosemite Valley Plan would restore approximately 175 acres, of which approximately 160 acres would be highly valued resource vegetation in Yosemite Valley. Such proposed actions include removal and restoration of several campgrounds, removal of roads through Stoneman and Ahwahnee Meadows, and natural vegetation restoration actions in several areas. Although certain Yosemite Valley Plan projects (such as construction of new parking and lodging facilities, and expansion of campgrounds in Yosemite Valley) have the potential to adversely affect local vegetation, these projects would be designed to ensure the long-term protection of sensitive vegetation communities consistent with the Merced River Plan and the park’s Vegetation Management Plan.

Cumulative actions could have a long-term, minor, beneficial cumulative effect on vegetation within Yosemite Valley due to the significant restoration efforts identified in the Yosemite Valley Plan. Alternative 2 would enhance the cumulative benefits from ecological restoration activities by removing utility infrastructure from the riverbanks and wet meadow areas identified for ecological restoration, thus enhancing restoration of natural hydrologic and vegetative processes.

Impairment

Alternative 2 would result in local, short-term and potentially long-term, minor to moderate, adverse effects on vegetation resources but provide for local, long-term, minor to moderate, beneficial effects on vegetation related to the removal of utilities from highly sensitive areas and the restoration of more natural subsurface water flows in meadows and riparian areas. Alternative 2 would also facilitate implementation of ecological restoration activities proposed in the Yosemite Valley Plan. This alternative would not impair the vegetation resources of the park.

Wildlife

Analysis

Implementation of Alternative 2 could disturb wildlife in the vicinity of construction activities. Effects would be related to heavy equipment and human intrusion and could include noise, dust generation, vegetation removal, trench excavation, or decreased oxygen levels in aquatic habitats. These actions could result in direct losses of nests, burrows, and wildlife, and indirect effects through the disturbance of nesting birds or roosting bats. The addition of pollutants (i.e., fuels or lubricants) related to equipment operations in these areas could degrade the quality of the environment and the wildlife habitat it provides. In addition, localized, long-term, adverse effects to wildlife due to routine clearance of vegetation at utility access manholes may also occur as a result of Alternative 2.

Most of the areas proposed for utility corridor construction have been previously disturbed by utilities, transportation facilities, or other development. Implementation of Alternative 2 would remove utility infrastructure in areas where ecological restoration is proposed.  Removal of utility infrastructure is expected to allow for the restoration of more natural subsurface hydrologic processes, enhancing meadow, riparian, and other wetland and aquatic habitats.  These three habitat types are considered among the highest valued habitats in the Valley.

Impacts to wildlife associated with Alternative 2 are described by area below. Table IV-9 provides the acreage by subarea of vegetation community types potentially affected by Alternative 2.

Happy Isles.  Localized, minor, short-term, adverse effects on native fish and wildlife could occur during construction activities in the Happy Isles area. Construction activities would have local, short-term, adverse, effects on up to 7.5 acres, which include 0.5 acre of riparian, a high value wildlife habitat. The wildlife habitat types that would be affected include montane riparian, ponderosa pine, sierra mixed conifer, and urban. Effects would be related to heavy equipment use and human intrusion and could include noise, dust, soil disturbance and compaction, vegetation removal, trench excavation, sedimentation, elevated turbidity, and decreased oxygen levels in aquatic habitats. These actions could result in direct losses of nests, burrows, wildlife, and reproductive habitat for aquatic organisms and indirect effects through the disturbance of nesting birds or roosting bats. The addition of pollutants (i.e., fuels, lubricants) related to equipment operations in these areas could degrade the quality of the environment and the wildlife habitat it provides. Some trees and shrubs that could provide roosts, perches, or nest sites may need to be removed to accommodate construction activities. In addition, localized, long-term, minor, adverse effects to wildlife due to routine clearance of vegetation at utility access manholes may also occur as a result of Alternative 2.

The application of mitigation measures described in Chapter II, particularly minimizing disturbance areas; installing fencing and signs to protect high value wildlife habitats; preserving, where possible, natural features with obvious high value to wildlife, such as tree snags; scheduling disruptive activities of construction in nesting habitat or hibernacula and maternity colony roosting habitat to occur outside the nesting season of birds and when bats are neither hibernating nor have young (e.g., birds breed from March to August, bats hibernate from September 1 to February 15, and bat young are nursing and unable to fly from May to mid August); instituting controls to prevent impacts to wildlife from excavations; limiting all work within the bed or banks of the Merced River to seasonal low water periods; developing and implementing a Stormwater Pollution Prevention Plan to control erosion, sedimentation, and compaction; and spill prevention; would reduce the potential for adverse impacts to native fish and wildlife to a minor intensity. Additional mitigation is described under the wetland and vegetation resource areas, as it relates to wildlife habitat avoidance, the minimization of impacts to wildlife habitat, and revegetation of disturbed portions of the project area. With the application of the mitigation measures, the size, continuity, and integrity of wildlife habitat as well as the abundance, diversity, and distribution of wildlife species would not be permanently impacted by construction activities associated with Alternative 2.

Campgrounds. Localized, minor, short-term, adverse effects on native fish and wildlife could occur during utility repair and construction activities. Construction activities in the Campgrounds area could potentially affect up to 34.4 acres, which specifically includes 0.1 acre meadow, 8.1 acres of riparian, and 1.00 acre of wetland and aquatic habitats, all high value wildlife habitats. The wildlife habitat types that would be affected include wet meadow, fresh emergent wetland, montane riparian, montane hardwood conifer, ponderosa pine, sierra mixed conifer, and riverine. Effects to native fish and wildlife related to construction activities would be similar to those discussed for the Happy Isles area. Localized, long-term, minor, adverse effects to wildlife due to routine clearance of vegetation at utility access manholes may also occur as a result of Alternative 2.

Utility removals would affect approximately 19.6 acres, which include 5.3 acres of riparian and 2.04 acres of wetland and aquatic habitats, both high value wildlife habitats. These removals would be expected to have local, short-term, minor adverse effects on wildlife, but the removals would also allow the restoration of more natural subsurface hydrologic processes in meadow, riparian, and other wetland and aquatic habitats, resulting in local, long-term, negligible to minor beneficial effects on wildlife.

The application of mitigation measures as discussed above for the Happy Isles area would reduce the potential adverse impacts to native fish and wildlife to a minor intensity.

Ecological Restoration Area. Localized, minor, short-term, adverse effects on native fish and wildlife could occur during construction and removal activities. Construction activities in the Ecological Restoration area could potentially affect up to 6.4 acres, which include 0.6 acre of riparian and 0.70 acre of wetland and aquatic habitats, both high value wildlife habitats. The wildlife habitat types that would be affected include wet meadow, montane riparian, montane hardwood conifer, ponderosa pine, sierra mixed conifer, riverine, and urban. Effects to native fish and wildlife related to construction activities would be similar to those discussed for the Happy Isles area. Localized, long-term, minor, adverse effects to wildlife due to routine clearance of vegetation at utility access manholes may also occur as a result of Alternative 2.

Utilities would be permanently removed and habitats restored over approximately 44.6 acres, which include 5.4 acres of meadow, 2.6 acres of riparian, and 7.85 acres of wetland and aquatic habitats, all high value wildlife habitats. These removals would be expected to have local, short-term, minor adverse effects on wildlife, but would also be expected to result in a local, long-term, negligible to minor, beneficial effects on wildlife from enhancing hydrologic processes in meadow, riparian, and other wetland and aquatic habitats.

The application of mitigation measures as discussed above for the Happy Isles area would reduce the potential adverse impacts to native fish and wildlife to a minor intensity.

The Ahwahnee. Localized, minor, short-term, adverse effects on native fish and wildlife could occur during construction and removal/abandonment activities. Construction activities in The Ahwahnee area could potentially affect up to 11.3 acres, which include 2.6 acres of meadow, 0.2 acre of riparian, and 1.03 acres of wetland habitat. The wildlife habitat types that would be affected include wet meadow, montane riparian, black oak woodland, montane hardwood, montane hardwood conifer, ponderosa pine, sierra mixed conifer, riverine, and urban. Effects to native fish and wildlife related to construction activities would be similar to those discussed for the Happy Isles area. Localized, long-term, minor, adverse effects to wildlife due to routine clearance of vegetation at utility access manholes may also occur as a result of Alternative 2.

Pipe bursting and utility line removal activities would occur over approximately 16.5 acres, which include 7.3 acres of meadow and 7.33 acres of wetland habitat, both highly valued resources. The utility removal and abandonment would be expected to have local, short-term, minor, adverse effects on wildlife, but enhancement of hydrologic processes in riparian and meadow habitats is expected to result in a local, long-term, negligible to minor, beneficial effect on wildlife.

The application of mitigation measures as discussed above for the Happy Isles area would reduce the potential adverse impacts to native fish and wildlife to a minor intensity.

Curry Village. Localized, minor, short-term, adverse effects on native fish and wildlife could occur during construction and removal activities. Construction activities in the Curry Village area could potentially affect up to 13.8 acres, which include 0.1 acre of riparian and 0.14 acre of wetland and aquatic habitats, both high value wildlife habitats. The wildlife habitat types that would be affected include wet meadow, montane riparian, montane hardwood conifer, ponderosa pine, sierra mixed conifer, and urban. Effects to native fish and wildlife related to construction activities would be similar to those discussed for the Happy Isles area. Localized, long-term, minor, adverse effects to wildlife due to routine clearance of vegetation at utility access manholes may also occur as a result of Alternative 2.

Removal of the water line would affect approximately 4.6 acres, which include specifically 1.9 acres of meadow, 0.3 acre of riparian, and 0.21 acre of wetland and aquatic habitats. These removals would be expected to have local, short-term, minor, adverse effects on wildlife, but enhancement of hydrological processes in riparian, meadow, wetland and other aquatic habitats isexpected to result in a local, long-term, negligible to minor, beneficial effect on wildlife.

The application of mitigation measures as discussed above for the Happy Isles area would reduce the potential adverse impacts to native fish and wildlife to a minor intensity.

Housekeeping Camp. Localized, minor, short-term, adverse effects on native fish and wildlife could occur during utility construction and removal. Construction activities in the Housekeeping Camp area could potentially affect up to 7.6 acres, which include 0.1 acre of riparian and 0.2 acre of wetland and aquatic habitats. The wildlife habitat types that would be affected include montane riparian, montane hardwood conifer, sierra mixed conifer, and riverine. Effects to native fish and wildlife related to construction activities would be similar to those discussed for the Happy Isles area. Localized, long-term, minor, adverse effects to wildlife due to routine clearance of vegetation at utility access manholes may also occur as a result of Alternative 2.

Utility removals within the Housekeeping Camp area would occur over approximately 1.4 acres and would not be anticipated to affect high value wildlife habitat. These removals would be expected to have local, short-term, minor, adverse effects on wildlife, but enhancement of hydrological processes in riparian and wetland and aquatic habitats is expected to result in a local, long-term, negligible to minor, beneficial effect on wildlife.

The application of mitigation measures as discussed above for the Happy Isles area would reduce the potential adverse impacts to native fish and wildlife to a minor intensity

Yosemite Village. Localized, minor, short-term, adverse effects on native fish and wildlife could occur during construction and removal/abandonment activities. Construction activities in the Yosemite Village area could potentially affect up to 25.8 acres, which include 2.8 acres of meadow, 0.2 acre of riparian, and 0.99 acre of wetland habitat. The wildlife habitat types that would be affected include wet meadow, montane riparian, California black oak woodland, montane hardwood conifer, ponderosa pine, sierra mixed conifer, and urban. Effects to native fish and wildlife related to construction activities would be similar to those discussed for the Happy Isles area. Localized, long-term, minor, adverse effects to wildlife due to routine clearance of vegetation at utility access manholes may also occur as a result of Alternative 2.

Abandonment of utilities within the Yosemite Village area would occur over approximately 3.9 acres, which include 0.2 acre of meadow and less than 0.01 acre of wetland habitat. These removals would be expected to have local, short-term, minor, adverse effects on wildlife, but enhancement of hydrological processes in meadow, riparian and other wetland habitats is expected to result in is expected to result in a local, long-term, negligible to minor, beneficial effect on wildlife.

The application of mitigation measures as discussed above for the Happy Isles area would reduce the potential adverse impacts to native fish and wildlife to a minor intensity.

Camp 6/Cook’s Meadow. Localized, minor, short-term, adverse effects on native fish and wildlife could occur during construction and removal/abandonment activities. Construction activities in the Camp 6/Cook's Meadow area could potentially affect up to 9.2 acres, which include 0.8 acre of meadow, 2.6 acres of riparian, and 1.82 acres of wetland and aquatic habitats, which are considered high value wildlife habitats. The wildlife habitat types that would be affected include wet meadow, montane riparian, California black oak woodland, montane hardwood conifer, ponderosa pine, sierra mixed conifer, riverine, and urban. Effects to native fish and wildlife related to construction activities would be similar to those discussed for the Happy Isles area. Localized, long-term, minor, adverse effects to wildlife due to routine clearance of vegetation at utility access manholes may also occur as a result of Alternative 2.

If Route Option A is implemented, there would be more acreage of meadow and oak wildlife habitats and less acreage of riparian wildlife habitat affected by Alternative 2. However, acreages of wildlife habitats are based upon vegetation mapping performed by NPS in 1994 (NPS 1994b) and reconnaissance-level field surveys performed in 2003 found that fewer well developed oak trees would be affected by Route Option A, and most of this segment is located in an open transitional area between meadow and oak woodland wildlife habitats. Route Option A would not result in a change to the overall intensity of impacts to wildlife resources in the Camp 6/Cook’s Meadow area.

Pipe bursting and abandonment of utilities within the Camp 6/Cook's Meadow area would occur over approximately 8.7 acres, which include 1.6 acres of meadow, 2.2 acres of riparian, and 1.82 acres of wetland and aquatic habitats. These removals would be expected to have local, short-term, minor, adverse effects on wildlife, but enhancement of hydrologic processes in riparian, meadow, and other wetland and aquatic habitats is  expected to result in a local, long-term, negligible to minor, beneficial effect on wildlife. The application of mitigation measures as discussed above for the Happy Isles area, and the use of directional drilling for the proposed Merced River crossing near Housekeeping Camp, if feasible, would reduce the potential adverse impacts to native fish and wildlife to a minor intensity.

Summary of Alternative 2 Impacts

Under Alternative 2, construction of integrated utility corridors and existing utility repairs are expected to have localized, short-term, adverse, construction-related impacts to approximately 116 acres, which include 6.3 acres of meadow, 12.4 acres of riparian, and 5.88 acres of wetland and aquatic habitats, all highly valued resources. There would also be localized, long-term, minor, adverse effects to wildlife due to routine clearance of vegetation at utility access manholes. The areas that would be affected are predominately within existing corridors that have previously been disturbed and developed, with the exception of the Merced River Crossing Utility Corridor.

Removal and abandonment activities are expected to have localized, short-term, adverse construction-related impacts to approximately 99 acres, which include 16.4 acres of meadow, 10.4 acres of riparian, and 20.12 acres of wetland and aquatic habitats, all highly valued resources. Removal of utilities in these areas is expected to restore more natural subsurface hydrological processes in riparian,  meadow, and other wetland and aquatic habitats, resulting in local, long-term, negligible to minor, beneficial effects to wildlife.

The combined impact to wildlife resources over the entire project area may result in short- and long-term, adverse impacts of minor intensity. Construction impacts would be mitigated through the application of mitigation measures described in Chapter II. Specifically, minimizing disturbance areas; installing fencing and signs to protect high value wildlife habitats; preserving, where possible, natural features with obvious high value to wildlife, such as tree snags; scheduling disruptive activities of construction in nesting habitat or hibernacula and maternity colony roosting habitat to occur outside the nesting season of birds and when bats are neither hibernating nor have young (e.g., birds breed from March to August, bats hibernate from September 1 to February 15, and bat young are nursing and unable to fly from May to mid August); instituting controls to prevent impacts to wildlife from excavations; limiting all work within the bed or banks of the Merced River to seasonal low water periods; developing and implementing a Stormwater Pollution Prevention Plan to control erosion, sedimentation, and compaction; and implementing spill prevention measures. With the application of the mitigation measures, the size, continuity, and integrity of wildlife habitat as well as the abundance, diversity, and distribution of wildlife species would not be permanently impacted by construction activities associated with Alternative 2.

Cumulative Impacts

Cumulative impacts to wildlife are based on analysis of past, present, and reasonably foreseeable future actions within Yosemite Valley in combination with potential effects of this alternative. The projects identified below include those projects that have the potential to affect local wildlife patterns.

Wildlife communities have been manipulated almost since the inception of the park. Regional wildlife has been historically affected by logging, fire suppression, rangeland clearing, grazing, mining, draining, damming and/or water diversions, and the introduction of non-native species. Park rangers trapped fur-bearing mammals until 1925; mountain lions were considered dangerous predators and controlled through the 1920s; and black bears were artificially fed as a tourist attraction until 1940. Natural wildland fires, with their generally beneficial effects on wildlife habitat, were routinely suppressed until 1972. Past and ongoing activities include recreational use and construction of bridges, diversion walls, roads, pipelines, riprap, buildings, campgrounds, and other recreational features.

Reasonably foreseeable future actions within Yosemite Valley are considered to have an overall net benefit to wildlife. For example, the Merced River Plan protects river-related natural resources through the application of management elements, including the River Protection Overlay, management zoning, protection and enhancement of Outstandingly Remarkable Values, and implementation of a Visitor Experience Resource Protection framework. Full implementation of the Yosemite Valley Plan would increase the size, continuity, and integrity of wildlife habitat in Yosemite Valley. Although certain Yosemite Valley Plan projects (such as construction or redevelopment of facilities in Curry Village or campground areas in the east Valley) have the potential to adversely affect local wildlife, these projects must be designed to ensure the long-term protection of sensitive vegetation communities consistent with the Merced River Plan and the Vegetation Management Plan. In addition, implementation of the Visitor Experience and Resource Protection framework (included in both the Merced River Plan and Yosemite Valley Plan) will help reduce adverse effects of visitor use on wildlife habitat and patterns.

Cumulative actions would have a local, long-term, minor to moderate, beneficial cumulative effect on wildlife within Yosemite Valley. Alternative 2 would reduce benefits in the short term, but would enhance the cumulative benefits from ecological restoration activities in the long-term by removing utility infrastructure from the riverbed, riverbanks, and wet meadow areas identified for ecological restoration.

Impairment

Alternative 2 would result in local, short and long-term, minor, adverse effects on wildlife resources but provide for local, long-term, minor, beneficial effects on wildlife resources related to the removal of utilities from highly sensitive habitat areas and restoration of more natural subsurface hydrologic processes in highly valued habitats. This alternative would not impair the wildlife resources of the park.

Special-Status Species

Analysis

Special-status species known or likely to occur in the immediate vicinity of Alternative 2 activities include the Wawona riffle beetle, Mariposa sideband snail, Sierra pygmy grasshopper, western pond turtle, 10 species of birds, 10 species of bats, and 14 species of plants. The following subsections discuss impacts that Alternative 2 would have on these species and their habitat. Implementation of Alternative 2 would require construction that could adversely affect special-status species in some areas, but also proposes removal of utility infrastructure in areas where ecological restoration is proposed. 

Impacts associated with Alternative 2 are described below.

Wawona Riffle Beetle. Construction activities and removal and abandonment activities in the vicinity of the Merced River may have localized, short-term, minor to moderate, adverse effects on the Wawona riffle beetle. Effects would be related to heavy equipment and human intrusion, and could include vegetation removal, decreased oxygen levels, the addition of silt, resuspension of sediment, or the introduction of pollutants (i.e., fuels or lubricants). These actions could result in direct losses of individuals or habitat for Wawona riffle beetle downstream of river crossings.

Alternative 2 would result in a local, long-term, minor, beneficial impact to Wawona riffle beetle habitat by enhancing river hydrology, water quality, and floodplains due to the reduction in utility river crossings, the removal of utility infrastructure from floodplain areas designated for ecological restoration, and restoration of more natural subsurface flows between the river and adjacent wetlands and floodplains.

If Route Option A is implemented, there would be no change in impacts to the Wawona riffle beetle.

The application of mitigation measures, as described in Chapter II, would reduce the potential short-term adverse impacts to Wawona riffle beetle to a minor intensity. Specifically, these measures would involve minimizing the area disturbed and implementing Best Management Practices during construction and restoration to reduce the potential for water quality impacts associated with soil erosion and construction equipment fuel releases. Directional drilling, if found to be technically and economically feasible, would be used to construct the proposed Merced River crossing at Housekeeping Camp, further reducing water quality and aquatic habitat impacts associated with the Wawona riffle bettle.

Mariposa Sideband Snail. Construction activities and removal and abandonment activities within rockslide habitat may have localized, short-term, minor to moderate, adverse effects on the Mariposa sideband snail. Effects would be related to heavy equipment and human intrusion and could include vegetation removal, direct disturbance of rockslide habitat, or the introduction of pollutants (i.e., fuels or lubricants). These actions could result in direct losses of individuals or habitat for the Mariposa sideband snail in rockslide areas.

If Route Option A is implemented, there would be no change in impacts to the Mariposa sideband snail.

The application of mitigation measures described in Chapter II, specifically minimizing the area disturbed, installing fencing and signs to protect sensitive habitat, and implementing spill prevention, would reduce the potential adverse impacts to the Mariposa sideband snail to a minor intensity.

Sierra Pygmy Grasshopper. Construction activities and removal and abandonment activities within riparian habitat may have localized, short-term, minor to moderate, adverse effects on the Sierra pygmy grasshopper. Effects would be related to heavy equipment and human intrusion and could include vegetation removal or the introduction of pollutants (i.e., fuels or lubricants). These actions could result in direct losses of individuals or habitat for the Sierra pygmy grasshopper.

Route Option A would not result in a change to the overall impacts to the Sierra pygmy grasshopper. However, if Route Option A is implemented, there would be less potential for impacts to the Sierra pygmy grasshopper due to the slight reduction in riparian habitat affected by Alternative 2.

Utility removals activities associated with Alternative 2 would result in local, short-term, minor, adverse effects on the Sierra pygmy grasshopper. The application of mitigation measures described in Chapter II, specifically minimizing the area disturbed, timing construction in riparian habitat outside the Sierra pygmy grasshopper's active period (e.g., schedule construction for the fall or winter), and implementing pollution prevention measures, would reduce the potential adverse impacts to the Sierra pygmy grasshopper to a minor intensity.

Western Pond Turtle. Construction activities and removal and abandonment activities in the vicinity of aquatic habitats may have localized, short-term, minor to moderate, adverse effects to the western pond turtle. Effects would be related to heavy equipment and human intrusion and could include vegetation removal, decreased oxygen levels, the addition of silt, resuspension of sediment, or the introduction of pollutants (i.e., fuels or lubricants). These actions could result in direct losses of individuals or habitat for the western pond turtle within aquatic habitats.

If Route Option A is implemented, there would be no change in impacts to the western pond turtle.

Utility removals activities associated with Alternative 2 would result in local, short-term, minor, adverse effects on the western pond turtle. The application of mitigation measures described in Chapter II would reduce the potential adverse impacts to western pond turtle to a minor intensity. Specifically, these measures would involve minimizing the area disturbed and implementing Best Management Practices during construction. Directional drilling, if found to be technically and economically feasible, would be used to construct the proposed Merced River crossing at Housekeeping Camp, further reducing water quality and aquatic habitat impacts associated with the Wawona riffle bettle.

Special-Status Species of Birds. Construction activities and removal and abandonment activities may have localized, short-term, minor to moderate, adverse effects on special-status birds in the immediate vicinity of these activities. Effects would be related to heavy equipment and human intrusion and could include disruption of breeding activities or the possible direct destruction or removal of nesting habitat or sites (e.g., snags and trees). Localized, long-term, minor, adverse effects to special-status bird species and their habitat may occur as a result of routine clearance of vegetation at utility access manholes.

Route Option A would not result in a change to the overall impacts to special-status species of birds. However, if Route Option A is implemented, there would be less potential for impacts to special-status species of birds due to the slight reduction in riparian habitat and the reduction of well developed oaks affected by construction.

Utility removals activities associated with Alternative 2 would result in local, short-term, minor, adverse effects., The application of mitigation measures described in Chapter II, specifically, implementing Best Management Practices, limiting construction activities to outside the breeding season for special-status bird species (e.g., birds breed from March through August), and conducting pre-construction surveys in appropriate habitats if construction activities during the breeding season cannot be avoided, would reduce the potential adverse impacts to special-status bird species to a minor intensity.

Special-Status Species of Bats. Construction activities and removal and abandonment activities may have localized, short-term, minor to moderate, adverse effects to special-status bat species in the immediate vicinity of these activities. Effects would be related to heavy equipment and human intrusion and could include disruption of breeding activities or the possible direct destruction or removal of bat roosts (e.g., snags and trees). Localized, long-term, minor, adverse effects to special-status bat species and their habitat may occur as a result of routine clearance of vegetation at utility access manholes.

Route Option A would not result in a change to the overall impacts to special-status species of bats. However, if Route Option A is implemented, there would be less potential for impacts to special-status species of bats due to the slight reduction in riparian habitat and the reduction of well developed oaks affected by construction.

Utility removals activities associated with Alternative 2 would result in local, short-term, minor, adverse effects on special-status bat species. The application of mitigation measures described in Chapter II, specifically, conducting preconstruction surveys in appropriate habitats if construction activities during hibernation and nursing periods cannot be avoided, minimizing removal of large oak trees and large snags, and scheduling disruptive activities of construction in hibernacula and maternity colony roosting habitat to occur when bats are neither hibernating nor have young (e.g., bats hibernate from September 1 to February 15 and bat young are nursing and unable to fly from May to mid August), would reduce the potential adverse impacts to special-status bat species to a minor intensity.

Special-Status Species of Plants. Construction activities and removal and abandonment activities may have localized, short-term, minor, adverse effects on special-status plant species in the immediate vicinity of these activities. Effects would be related to the use of heavy equipment during excavation and repair activities and could include soil disturbance and compaction, dust generation, vegetation removal, root damage, erosion, introduction and spread of non-native species, or the introduction of pollutants (i.e., fuels or lubricants).

If Route Option A is implemented, there would be no change in impacts to special-status species of plants.

Utility removals activities associated with Alternative 2 could result in local, short-term, minor, adverse effects on special-status species of plants. The application of mitigation measures described in Chapter II, particularly performing rare plant surveys prior to construction in appropriate habitats and at appropriate times (e.g., during plant species flowering periods), avoiding special-status species of plants to the extent possible, minimization of disturbance areas, and implementing a noxious weed abatement program, would reduce the potential adverse impacts to special-status plant species to a minor intensity. Localized, long-term, minor, adverse effects to special-status plant species may occur as a result of routine clearance of vegetation at utility access manholes.

Summary of Alternative 2 Impacts

Impacts to special-status species under Alternative 2 would be local, short-term and long-term, minor to moderate, and adverse during construction and removal activities. With implementation of mitigation measures identified to reduce adverse effects, the overall effect from Alternative 2 would be local, short and long-term, minor, and adverse.  No critical habitat for special-status species would be affected.

Cumulative Impacts

Cumulative effects to special-status species are based on analysis of past, present, and reasonably foreseeable future actions within Yosemite Valley in combination with potential effects of this alternative. The projects identified below include those projects that have the potential to affect local special-status species.

Natural habitats in Yosemite Valley have been manipulated since the inception of Yosemite National Park. Regional wildlife and vegetation patterns have been historically affected by logging, fire suppression, rangeland clearing, grazing, mining, draining, damming and diversions, and the introduction of non-native species. Past and ongoing activities that affect special-status species include recreational use and construction of bridges, diversion walls, roads, pipelines, riprap, buildings, campgrounds, and other recreational features.

Reasonably foreseeable future actions within Yosemite Valley are considered to have an overall net benefit to special-status species. For example, the Merced River Plan protects river-related natural resources through the application of management elements, including the River Protection Overlay, management zoning, protection and enhancement of Outstandingly Remarkable Values, and implementation of a Visitor Experience Resource Protection framework.

Full implementation of the Yosemite Valley Plan would increase the size, continuity, and integrity of habitats, especially meadow, riparian, California black oak, and upland habitats, for special-status species in Yosemite Valley. Although certain Yosemite Valley Plan projects, such as construction of new lodging and parking facilities, and expansion of campgrounds in Yosemite Valley, have the potential to adversely affect local special-status species, these projects must be designed to ensure the long-term protection of special-status species consistent with the Merced River Plan and the Endangered Species Act. In addition, implementation of the Visitor Experience and Resource Protection framework (included in both the Merced River Plan and Yosemite Valley Plan) will help reduce adverse effects of visitor use on special-status species.

Cumulative actions would have a local, long-term, moderate, beneficial cumulative effect on special-status species within Yosemite Valley. Alternative 2 would enhance the cumulative benefits from ecological restoration activities by removing utility infrastructure from the riverbed, riverbanks, and wet meadow areas identified for ecological restoration, thus enhancing habitat for special-status species.

Impairment

Alternative 2 would result in local, short-term, minor, adverse impacts to special-status species in the immediate vicinity of construction activities, but would also provide for local, long-term, minor, beneficial effects on special-status species related to the removal of utilities from highly sensitive areas and restoration of more natural subsurface water flows in those areas. Therefore, Alternative 2 would not impair park resources for future generations.

Air Quality

Analysis

Alternative 2 would include use of construction equipment to develop new integrated utility corridors and remove most utility infrastructure from environmentally sensitive areas. Air quality effects from this alternative would relate primarily to construction equipment emissions and dust generated during construction activities. Emissions from construction equipment would occur in the vicinity of construction activities and could result in mildly unpleasant odors that could be noticeable to park visitors in nearby areas. Construction activities in each area are expected to be of relatively short duration, and many repairs would be timed during the fall and winter when visitor levels are lowest. Use of Best Management Practices (e.g., site watering, covering stockpiles, covering haul trucks, and vehicle emission controls) to reduce both tailpipe and fugitive dust emissions would be made a condition of construction contractor agreements.

Alternative 2 would result in an increase in air emissions related to utility operations through the addition of four additional lift stations in Yosemite Valley. Although the addition of these lift stations is not expected to substantially change electric power demand for Valley utilities, emergency generators would also be included in new lift stations to ensure safe utility operations in the event of an electric power failure. This alternative calls for the addition of four emergency generators to the existing seven emergency generators currently associated with utility facilities in Yosemite Valley. Emergency generators are only run for short durations for testing purposes twice a month. Therefore, the additional emissions from these generators are expected to be negligible. Alternative 2 would have a regional, long-term, negligible, adverse effect on air quality.

If Route Option A is implemented, there would be no change in impacts to air quality.

Summary of Alternative 2 Impacts

Alternative 2 would result in local, short-term, minor, adverse impacts to air quality from construction as well as local, long-term, negligible, adverse effects on air quality from operations.

Cumulative Impacts

Cumulative effects to air quality are based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley in combination with potential effects of Alternative 2. The projects identified below include those projects within Yosemite Valley that could affect air quality or that could be affected by air pollutant sources within Yosemite Valley.

Since 1950, the population of California has tripled, and the rate of increase in vehicle-miles-traveled has increased six-fold. Air quality conditions within the park have been influenced by this surge in population growth and associated emissions from industrial, commercial, and vehicular sources in upwind areas. Since the 1970s, emissions sources operating within the park, as well as California as a whole, have been subject to local stationary-source controls and state and federal mobile-source controls. With the passage of time, such controls have been applied to an increasing number of sources, and the associated requirements have become dramatically more stringent and complex. In the 1980s, a Restricted Access Plan was developed for use when traffic and parking conditions in Yosemite Valley become congested. The plan has the effect of reducing the number of incoming vehicles and their related emissions until the traffic volume and parking demand in Yosemite Valley decrease sufficiently (as visitors leave the Valley) to stabilize traffic conditions.

YARTS is a multi-agency effort to provide transportation options, reduce reliance on automobiles, and improve regional air quality. Efforts underway under this project are expected to result in long-term, beneficial impacts on air quality throughout the region.

The Yosemite Valley Plan proposes to enhance the quality of the visitor experience in Yosemite Valley by reducing automobile congestion and limiting crowding. It also proposes traffic management systems and options for the size and placement of parking lots, both within and outside of Yosemite Valley. Parking lot(s) outside the Valley could be used to intercept day visitors and shift those visitors to Valley-bound shuttle buses. The Yosemite Valley Plan would have a long-term, moderate, adverse impact on nitrogen oxide emissions from the use of diesel buses through 2015, but long-term, minor to major, beneficial impacts to volatile organic compounds, carbon monoxide, and particulate matter emissions.

The purpose of the Merced River Plan is to protect and enhance the Outstandingly Remarkable Values and free-flowing condition of the river for the benefit and enjoyment of present and future generations. The protection of natural resources under this plan would benefit air quality.

Reasonably foreseeable future actions proposed for Yosemite Valley could have beneficial or adverse impacts on air quality. For example the National Park Service’s Shuttle Bus Replacement Project could have a net beneficial effect on air quality by improving the attractiveness of alternative modes of transportation and thereby reducing private automobile trips. Although the Shuttle Bus Replacement Project would have localized, short-term, adverse air quality effects, the general goal of the project is to relieve congestion and provide for alternative means of transportation. As such, this project would encourage travel to the park by alternative (nonprivate vehicle) modes and would have a long-term, beneficial effect on air quality.

Other reasonably foreseeable future National Park Service projects, such as the Eagle Creek Merced River Ecological Restoration Project and Trail Reconstruction from Happy Isles to Vernal Fall, are not anticipated to have a net adverse or beneficial effect on air quality except for short-term, localized impacts during construction.

Although cumulative growth in the region will tend to adversely affect air quality, implementation of ongoing state and federal mobile-source control programs would ameliorate this effect to a degree. With respect to particulate matter, conditions in the Valley would be determined by both regional sources and local sources and could be beneficial or adverse. Considered with the adverse impacts associated with regional air quality influences, the cumulative projects would have a local, long-term, moderate, beneficial effect on air quality in Yosemite Valley.

Alternative 2 and the cumulative projects discussed above would result in local, long-term, moderate, beneficial impacts on air quality. The local, short-term, minor adverse effects associated with construction emissions and the regional, long-term, negligible, adverse effects from new utility equipment would not offset the long-term, beneficial effects of the cumulative projects.

Impairment

Implementation of Alternative 2 is expected to result in local, short-term, minor, adverse air quality impacts from construction activities and regional, long-term, negligible adverse air quality impacts from operations. These minor short-term and negligible, long-term impacts are not expected to impair park resources for future generations.

Noise

Analysis

Alternative 2 would involve operation of heavy-duty construction equipment to construct utility corridors and to remove utility infrastructure from areas identified for ecological restoration. Since utility infrastructure is proposed to follow existing roadways and be located in developed areas, park visitors and residents could be impacted during construction activities. As described under Alternative 1, construction noise levels would vary depending on a number of factors, such as the number and type of equipment in operation on a given day, usage rates, the level of background noise in the area, and the distance between sensitive uses and the construction site.

Happy Isles. Construction of the proposed utility corridor in the Happy Isles area would occur across the Merced River from the Mist Trail, and park visitors hiking on this trail or visiting the Happy Isles Nature Center could be impacted during construction activities. This alternative would result in local, short-term, moderate to major, adverse noise impacts on park visitors.

Campgrounds. Construction of utility corridors within the Campgrounds area is proposed to be coordinated with campground redevelopment and road realignment. It is expected that park visitors would be directed away from these construction areas during these activities. However, construction-related noise could impact park visitors traveling through the area to access trails along the Merced River or Tenaya Creek. Noise impacts in this area would be local, short-term, moderate to major, and adverse.

Ecological Restoration Area. Utility corridor construction and utility line removal actions in the Ecological Restoration area could result in local, short-term, minor to moderate, adverse noise impacts to visitors in the vicinity of Housekeeping Camp, Ahwahnee Meadow, and Stoneman Bridge. Removal actions in this area are expected to be coordinated with additional construction activities associated with the ecological restoration of these areas. Construction noise impacts are expected to be local, short-term, moderate to major in intensity, and adverse.

The Ahwahnee. Alternative 2 proposes construction of utility corridors along the edge of Lower Tecoya Housing and along Ahwahnee Road to The Ahwahnee. Construction noise impacts to park visitors and residents would be adverse, local, moderate to major in intensity, and short-term in duration.

Curry Village. Utility infrastructure construction activities in the Curry Village area are expected to be coordinated with other construction activities in Curry Village, such as the construction of the Curry Village Dormitory. Construction-related noise impacts in this area would have the potential to affect employees housed in this area as well as park visitors. Although these adverse impacts could be moderate to major in intensity, the impacts would be local and short-term in duration.

Housekeeping Camp. Construction of proposed utility infrastructure within Housekeeping Camp could impact park visitors and contractors in the vicinity of Housekeeping Camp. These construction-related impacts would be adverse, local, moderate to major in intensity, and short-term in duration.

Yosemite Village. Proposed utility facility construction within the Yosemite Village area would occur primarily along the major roadways in the area. Although park visitors would likely be routed away from construction areas during construction activities, construction noise is likely to have local, short-term, moderate to major impacts on park visitors and residents.

Camp 6/Cook’s Meadow. Construction of the utility corridor across the Merced River near Housekeeping Camp is likely to result in adverse noise impacts to park visitors, particularly those accessing the Sentinel Bridge area. These construction impacts are expected to be local, short-term, moderate to major, and adverse.

If Route Option A is implemented, there would be no change in noise-related impacts.

Summary of Alternative 2 Impacts

Construction of utility corridors and associated infrastructure is expected to result in local, short-term, moderate to major, adverse impacts to park visitors, residents, and contractors. Alternative 2 is not expected to have any long-term impacts on ambient noise levels in Yosemite Valley.

Cumulative Impacts

Cumulative effects to the ambient noise environment are based on the analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley in combination with potential effects of this alternative. The projects identified below include those projects within Yosemite Valley that could affect noise within the east Valley.

The Yosemite Valley Plan proposes to enhance the quality of the visitor experience in Yosemite Valley by reducing automobile congestion, limiting crowding, and expanding orientation and interpretation services. It also proposes traffic management systems and options for the size and placement of parking lots, both within and outside of Yosemite Valley. Parking lots outside the Valley could be used to intercept day visitors and shift those visitors to Valley-bound shuttle buses. Overall, general sound levels associated with traffic along most roadways in the Valley would be reduced, representing a long-term beneficial impact.

The purpose of the Merced River Plan is to protect and enhance the Outstandingly Remarkable Values and free-flowing condition of the river for the benefit and enjoyment of present and future generations. The protection of natural resources and maintenance of visitor-intensive uses in the appropriate management zones under this plan would have beneficial effects on the noise environment.

Reasonably foreseeable future actions proposed for Yosemite Valley could have beneficial or adverse impacts on noise. For example, the National Park Service’s Shuttle Bus Replacement Project could have a net beneficial effect on the ambient noise environment by improving the attractiveness of alternative modes of transportation, thereby reducing private automobile trips. Although the Shuttle Bus Replacement Project would increase the frequency of bus trips and related localized, short-term, adverse noise effects, noise levels generated by individual buses will decrease. The general goal of the project is to relieve congestion and provide for alternative means of transportation. As such, this project would encourage travel to the park by alternative (nonprivate vehicle) modes and would have a long-term, beneficial effect on noise. To the extent that transportation-related projects would replace automobile trips in the Valley with bus trips, the anticipated beneficial effect would depend on ridership levels (and the corresponding number of automobile trips that would be avoided) and the technology selected for the buses.

Other reasonably foreseeable future National Park Service projects, such as Eagle Creek Merced River Ecological Restoration and Happy Isles to Vernal Fall Trail Reconstruction, are not anticipated to have a net adverse or beneficial effect on the ambient noise environment except for short-term, localized impacts during construction.

The gradual increase in annual visitation to the park would likely offset the beneficial effects of cumulative actions that would tend to reduce vehicle trips and their associated noise, resulting in a local, long-term, minor, adverse effect on the noise environment.

Alternative 2 would contribute to the cumulative minor, adverse effect in the short term due to construction noise associated with implementation of the alternative.

Impairment

Alternative 2 would result in local, short-term, moderate to major, adverse noise effects on park visitors and residents during construction activities. Alternative 2 is not expected to have any long-term, adverse effects on noise and is not expected to impair park resources for future generations.

Cultural Resources

Archeological Resources

Analysis

The actions proposed in Alternative 2 have the potential to affect archeological sites recorded within the Area of Potential Effect of existing or proposed utility corridors, associated facilities (e.g., lift stations), and utility removal or abandonment actions. Impacts would be associated with construction activities such as clearing, excavating, filling, and grading. These activities may impact unrecorded buried cultural resources as well; this is particularly true in areas proposed for new corridors or facilities, but also may occur along existing corridors where previous excavations were not observed by archeologists. The park’s standard procedure of having ground-disturbing activities monitored by an archeologist would reduce potential impacts to cultural resources uncovered during construction. Potential indirect impacts on cultural resources from changes in traffic patterns discussed under Alternative 1 apply to Alternative 2 as well.

Impacts associated with Alternative 2 are described by subarea below.

Happy Isles. Potential impacts in this area would be similar to those noted for Alternative 1. There are no recorded sites in the Happy Isles project area. Minimizing the area disturbed and monitoring excavation will reduce the potential for destruction of unrecorded buried cultural material.

Campgrounds. Intact sediments at up to seven archeological sites in the Campgrounds area would be disturbed by grading, trenching, and earthmoving activities necessary to install new or redevelop existing utility corridors under Alternative 2.  These sites consist of prehistoric and historic American Indian habitation sites ranging in estimated data potential from low to high. None of the sites have been subject to test excavations to determine their nature, extent, integrity and specific data potential, so the boundaries are based only on surface observations and their potential eligibility for inclusion in the National Register of Historic Places is unknown. These sites will be evaluated through test excavations and where utility line construction would result in further loss of important archeological information, data recovery to retrieve important information, carried out in accordance with the 1999 Programmatic Agreement, would reduce the intensity of permanent adverse impacts from moderate to minor.  

Previous testing and data recovery excavations at one of these sites focused on the southeast portion of the site where a comfort station was constructed. The north and west boundaries of the site, in the direction of proposed actions under Alternative 2, have not been firmly delineated. Further testing will occur in this area, and data recovery, if important deposits are identified, would be carried out in accordance with the 1999 Programmatic Agreement to mitigate for the adverse effect and to reduce the impact from moderate to minor.

A known burial occurs within one of the sites near the proposed Tenaya Creek Campground Utility Corridor.  Additional burials may be present in the area, therefore, construction activities proposed under this alternative would result in an adverse effect and permanent, major, adverse impacts. To mitigate these impacts, a testing plan that includes a human remains discovery plan will be developed and implemented in consultation with the State Historic Preservation Officer and culturally affiliated tribes. Construction at this site will not proceed until potential impacts of trenching identified by the testing are appropriately mitigated to a minor level.    

Ecological Restoration Area. Potential impacts in this area would be similar to those noted in the Alternative 1 discussion earlier in the chapter. There are no recorded sites in the Ecological Restoration area.  Minimizing the area disturbed and monitoring excavation would reduce the potential for destruction of unrecorded buried cultural material.

The Ahwahnee.  Important deposits at five sites in The Ahwahnee area may be impacted by grading, trenching, and earthmoving activities under Alternative 2. These sites consist of prehistoric and historic American Indian habitation sites and historic Euroamerican habitation and recreation sites ranging in estimated data potential from moderate to high.  As noted for Alternative 1, The Ahwahnee is recorded as a single historic property with an archeological site. The boundaries of this site fully encompass the hotel and extend varying distances from it in all directions. Proposed actions under Alternative 2, including installation of a new lift station west of the hotel, would require excavation south and west of the hotel in areas where the archeological site boundaries are not firmly delineated. These areas will be evaluated through test excavations and where utility line construction would result in loss of important archeological information, data recovery to retrieve important information, carried out in accordance with the 1999 Programmatic Agreement, would reduce the intensity of permanent adverse impacts from major to minor.

The currently understood boundaries of a second site in this area encompass The Ahwahnee Bungalows and extend well north of the access road north of the bungalows. Testing of this large site in response to the proposed utility corridor construction and utility removals may be limited to the parts of the site that would be impacted by these activities. If determined to be required based upon testing results, data recovery would be carried out in accordance with the 1999 Programmatic Agreement to mitigate for the adverse effect.and reduce the impact from moderate to minor.

Work in this area also has the potential to impact a third site, which may be associated with the traditional American Indian habitation site of Wiskalah (Bibby 1994). This site will be evaluated through test excavations and where utility line construction would result in loss of important archeological information, data recovery to retrieve important information, carried out in accordance with the 1999 Programmatic Agreement, would reduce the intensity of permanent adverse impacts from moderate to minor.

Two other sites will be evaluated through test excavations and where utility line construction would result in loss of important archeological information, data recovery to retrieve important information, carried out in accordance with the 1999 Programmatic Agreement, would reduce the intensity of permanent adverse impacts from moderate to minor. 

Replacement of several lines by pipe bursting is proposed in the vicinity of several recorded sites in The Ahwahnee area, which would require excavation at existing manhole locations. These excavations would be limited to the previously disturbed sediments in each of these locations and is not expected to result in further disturbance of these sites.

Alternative 2 also proposes to remove utilities in the southern (meadow) and eastern portions of The Ahwahnee area. It is recommended that these utilities be abandoned in place rather than removed. If abandonment is not possible, subsurface inventory would be conducted prior to construction activities to verify that subsurface cultural materials would not be disturbed. In the vicinity of utility work southeast of the hotel, subsurface inventory also would need to establish the southern boundaries of a known site. If subsurface inventory reveals the presence of intact deposits, the site will be evaluated through test excavations and where utility line construction would result in loss of important archeological information, data recovery to retrieve important information, carried out in accordance with the 1999 Programmatic Agreement, would reduce the intensity of permanent adverse impacts from moderate to minor.

Curry Village. Two areas of construction-related activity in the Curry Village area have the potential to impact cultural resources. A new lift station and the proposed wastewater line replacement may impact one unevaluated site. This site is judged to be of moderate data potential.  The site will be evaluated through test excavations and, where construction would result in loss of important archeological information, data recovery to retrieve important information, carried out in accordance with the 1999 Programmatic Agreement, would reduce the intensity of permanent adverse impacts from moderate to minor or negligible.

Pipe bursting repairs proposed in this area have the potential to impact a site recorded directly to the south of the wastewater line that is thought to be of low data potential. While the boundaries of the site have not been determined by testing, potential impacts to the site would be avoided by limiting excavation at the three manholes to the area of the original installation excavation. These excavations would be monitored as discussed earlier.

Housekeeping Camp. Intact sediments at two archeological sites in the Housekeeping Camp area would be disturbed by grading, trenching, and earthmoving activities necessary to install new or redevelop existing utility corridors under Alternative 2.  One site, associated with the Native American historic habitation site of Holow (Bibby 1994), has been determined eligible for the National Register of Historic Places by previous archeological excavations and is considered of high data potential. Construction would likely encounter additional significant cultural materials, especially north of Southside Drive, and data recovery to retrieve important information, carried out in accordance with the 1999 Programmatic Agreement, would reduce the intensity of permanent adverse impacts from moderate to minor.

A burial was also found in this area during previous construction work (Danziger 1980). The boundaries of this site, judged to be of low data potential, have never been determined through testing and may be impacted by proposed construction activities. Testing will be conducted to determine site boundaries and subsurface contents under a scope of work that includes a discovery plan for human remains. When this site’s boundaries have been established and its contents understood, consultation with the State Historic Preservation Officer and culturally associated American Indian groups would occur in compliance with Stipulation VIIIB of the 1999 Programmatic Agreement if evidence of the presence of human remains was found.  If this consultation cannot resolve the potential adverse effect, than the utility corridor would be re-routed to avoid the area with human remains.  If evidence of human remains is not found by the site evaluation work, but other important deposits are identified, data recovery would be carried out in accordance with the 1999 Programmatic Agreement to reduce the intensity of permanent adverse impacts from moderate to minor.

Yosemite Village. Intact sediments at up to four archeological sites in the Yosemite Village area would be disturbed by grading, trenching, and earthmoving activities necessary to install new or redevelop existing utility corridors under Alternative 2.  The four sites range in data potential from low to high.  As noted in the discussion of Alternative 1, the area encompassed by Yosemite Village includes multiple archeological sites now considered as a single site area, portions of which would be affected under Alternative 2. The following recommendations are based on previous work that has occurred in different parts of this site complex.

Construction activities in the vicinity of the Village Store may impact the area originally recorded as the approximate boundary between two sites. The data potential of this area is considered to be low. Construction activities would stay within the road prism to avoid impacting important cultural materials in this area and would be monitored according to the 1999 Programmatic Agreement.

The work proposed in the southwest portion of Yosemite Village and along Northside Drive is of particular concern because it occurs within two associated sites. These sites have been demonstrated through previous testing and data recovery projects to possess important cultural materials that have a high potential for additional information important to understanding the prehistory of the area. Data recovery excavations would be carried out in accordance with the 1999 Programmatic Agreement to mitigate for the adverse effect on these sites. The combined results of these mitigation measures would reduce the intensity of impacts from moderate to minor.

In addition, two existing wastewater lines in this area are proposed for pipe bursting and abandonment. Care would be taken in moving equipment or any other potentially ground-disturbing activities in this area to avoid important deposits that may be associated with another archeological site recorded just to the west in this area.

The other two sites in the Yosemite Village area have only been recorded based on surface observations. These sites would be tested prior to construction to verify whether proposed activities would impact subsurface cultural materials.  Data recovery, if required based on testing results, would be carried out in accordance with the 1999 Programmatic Agreement to mitigate for the adverse effect and to reduce the intensity of permanent adverse impacts from moderate to minor.

Camp 6/Cook’s Meadow. Intact sediments at two archeological sites in the Camp 6/Cook’s Meadow area may be disturbed by grading, trenching, and earthmoving activities necessary to install new or redevelop existing utility corridors under Alternative 2.

The Yosemite Creek Utility Corridor west of Residence 1 utility corridor would affect a known site. This site has been evaluated and found to contain important cultural deposits.  Data recovery excavations have previously been conducted to mitigate impacts of construction in the northeast portion of the site.  The data potential for the balance of the site is considered high, and data recovery excavations will be conducted in the portion of the site to retrieve important information prior to ground-disturbing activities in this area.  These excavations, carried out in accordance with the 1999 Programmatic Agreement, would reduce the intensity of permanent adverse impacts from moderate to minor.

A site on the north side of the Merced River near Sentinel Bridge also could be impacted by the proposed pipe bursting and abandonment of the existing wastewater line that runs east to west through this area. This site has been investigated in the past, including data recovery excavations. Further testing is not needed, but ground disturbance at manhole locations would still be restricted to areas that have been previously disturbed.

Construction of Route Option A at the west end of the Camp 6/Cook’s Meadow area has the potential to impact the same archeological site as discussed in relation to Alternative 2.  Route Option A would not result in a change to the overall impacts to archeological resources in the area. 

Summary of Alternative 2 Impacts

Alternative 2 has the potential to affect 22 known archeological sites. Of these sites, six have low data potential, seven have moderate data potential, and nine have high data potential.  Impacts to three sites can be mitigated through avoidance.  Data recovery will be required at three sites.  Sixteen sites would be tested to determine if the impacts at these locations would produce adverse effects. If testing determines that the sites are National Register of Historic Places-eligible, data recovery excavations would be carried out in accordance with the 1999 Programmatic Agreement to mitigate for the adverse effect. Adverse effects to three previously evaluated, National Register of Historic Places-eligible sites would also be mitigated by data recovery excavation in accordance with the Programmatic Agreement, thus mitigating the National Historic Preservation Act adverse effect and reducing the major to moderate impacts under NEPA to minor.

Cumulative Impacts

Cumulative impacts to archeological resources are based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley in combination with potential effects of this alternative. Assessment of cumulative effects is hampered by a lack of information for untested sites throughout the Valley. Development of facilities within Yosemite Valley has disturbed or destroyed numerous archeological resources and compromised the integrity of numerous other such resources, which has had an adverse cumulative effect on archeological resources.

Reasonably foreseeable future actions proposed in the region that could have an adverse cumulative effect on archeological resources in Yosemite include any development-related projects that include excavation, such as Curry Village Employee Housing, Eagle Creek Merced River Ecological Restoration, Ecological Restoration of Flood-Damaged Campgrounds, Lower Yosemite Fall Project, and Curry Village and East Yosemite Valley Campground Improvements. Excavations and other construction activities related to these cumulative projects could disturb individual archeological resources, which are located throughout the Valley. The Yosemite Valley Plan would have a local, long-term, adverse cumulative effect on cultural resources in Yosemite Valley due to possible disturbance associated with earth-moving, construction, and demolition projects. The National Park Service would follow guidelines of the 1999 Programmatic Agreement and avoid adverse effects to archeological resources to the greatest extent feasible.

The Merced River Plan provides a framework for decision-making on future management actions within the Merced River corridor through the application of a consistent set of decision-making criteria and considerations composed of seven management elements: boundaries, classifications, Outstandingly Remarkable Values, the Section 7 determination process, management zoning, the River Protection Overlay, and the Visitor Experience and Resource Protection framework. The Merced River Plan calls for protection of cultural resources and would have a local, long-term, minor, beneficial cumulative effect on archeological resources.

The cumulative projects within and in the vicinity of the Yosemite Valley would result in a local, long-term, negligible to minor, adverse impact on archeological resources due to the potential disturbance of such resources during subsurface excavations associated with development projects. Alternative 2 would contribute to the local, long-term, negligible to minor, cumulative adverse effects on these resources. Potential adverse effects from Alternative 2 and the other cumulative projects would be mitigated through data recovery where required to resolve potential adverse effects.

Impairment

Potential adverse effects associated with activities under Alternative 2 are expected to be mitigated through investigation and data recovery, where appropriate, and would not impair the park’s archeological resources for future generations.

Traditional Cultural Resources

Analysis

The potential effects of actions under Alternative 2 would be similar to but more widespread than those discussed under Alternative 1. All of the historic American Indian habitation sites and traditional cultural resource areas discussed under Alternative 1 would also be impacted by Alternative 2. The potential effects are discussed for each area below.

Happy Isles. Although no specific, known traditional cultural resources have been identified within the Area of Potential Effect for Alternative 2 in this area, it is likely that traditionally used plants occur in the area. Construction activities in this area would be expected to have local, short-term, minor, adverse effects on the availability and use of these resources. Consultation with culturally associated American Indian tribes has resulted in a number of mitigation measures designed to reduce potential impacts to traditional cultural resources, including minimizing disturbance of areas that have not been previously disturbed; soil salvage, storage, and disposal measures; pre-construction site reconnaissance for plants to be salvaged; tribal participation in development and implementation of revegetation plans; and other measures as described in the mitigation measures discussion in Chapter II.

Campgrounds. As discussed under Alternative 1, activities proposed in this area could affect a historic American Indian habitation sites (Ummataw) and two gathering areas for mushrooms. Proposed activities in the Lower Pines Campground could affect an additional mushroom gathering area. Construction activities in this area would likely result in local, short-term, minor to moderate, adverse impacts. Consultation has identified mitigation measures to minimize adverse effects as discussed above under the Happy Isles subarea and in the mitigation measures discussion in Chapter II.

Ecological Restoration Area. Although no specific traditional cultural resources have been identified within the Area of Potential Effects for Alternative 2 in the Ecological Restoration area, it is likely that some traditionally utilized plant resources are present. Construction activities in this area would likely result in local, short-term, minor to moderate, adverse impacts. Consultation has identified mitigation measures to minimize adverse effects as discussed above for the Happy Isles area and in the mitigation measures discussion in Chapter II.

The Ahwahnee. In addition to the historic American Indian habitation area of Wiskalah discussed under Alternative 1, construction activities in this area could impact a deergrass gathering area at the north end of Ahwahnee Meadow. Construction activities in this area would likely result in local, short-term, minor to moderate, adverse impacts. Consultation has identified mitigation measures to minimize adverse effects as discussed above for the Happy Isles area and in the mitigation measures discussion in Chapter II.

Curry Village. Proposed utility corridor construction in the Curry Village area could affect a historic American Indian habitation area (Toolahka).  Construction activities in this area would likely result in local, short-term, minor to moderate, adverse impacts. Consultation has identified mitigation measures to minimize adverse effects, as discussed above for the Happy Isles area and in the mitigation measures discussion in Chapter II.

Housekeeping Camp. Proposed activities in the Housekeeping Camp area could affect a historic American Indian habitation area (Holow/Tuyuyuyu), as discussed under Alternative 1. Construction activities in this area would likely result in local, short-term, minor to moderate, adverse impacts. Consultation has identified mitigation measures to minimize adverse effects, as discussed above for the Happy Isles area and in the mitigation measures discussion in Chapter II. 

Yosemite Village. Alternative 2 could affect the Ahwahnee and Yowatchke historic American Indian habitation areas and traditional California black oak use areas. Construction activities in this area would likely result in local, short-term, minor to moderate, adverse impacts. Consultation has identified mitigation measures to minimize adverse effects, as discussed above for the Happy Isles area and in the mitigation measures discussion in Chapter II.

Camp 6/Cook’s Meadow. Activities proposed under Alternative 2 in this area could affect a traditional strawberry gathering area, a sedge and bracken fern gathering area, and a mushroom gathering area. Construction activities in this area would likely result in local, short-term, minor to moderate, adverse impacts. Consultation has identified mitigation measures to minimize adverse effects, as discussed above for the Happy Isles area and in the mitigation measures discussion in Chapter II.

If Route Option A is implemented, less traditional cultural resources (large, well-developed
Black Oak trees, mushrooms, and bracken fern) would be impacted by construction in the
Camp 6/Cook’s Meadow area.  This would reduce the overall level of impacts to traditional cultural resources in this area. 

Summary of Alternative 2 Impacts

Construction activities associated with Alternative 2 would likely result in local, short-term, minor to moderate, adverse impacts to traditional cultural resources, including eight traditional gathering areas and six historic Native American habitation sites. The park has initiated consultation with culturally associated American Indian tribes regarding the potential impacts on traditional cultural resources and has through consultation developed mitigation measures to minimize these impacts. Implementation of these mitigation measures would reduce the intensity of long-term, adverse impacts to minor under NEPA.

Cumulative Impacts

Cumulative impacts to traditional cultural resources discussed herein are based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley in combination with potential effects of this alternative. Development, operation, and maintenance of facilities in the Valley has disturbed, destroyed, or impacted the integrity of numerous traditional cultural resources, which has had an adverse cumulative effect. Nevertheless, Yosemite Valley retains many sites and resources of significance to local and culturally associated American Indians.

Reasonably foreseeable future actions proposed in the region, including development and maintenance projects under the Yosemite Valley Plan, could have an adverse cumulative effect on traditional cultural resources. Projects proposed under the Yosemite Valley Plan would result in expanded development and disturbance of traditional gathering areas and historic American Indian habitation sites. In recognition of the potential for future impacts to traditional cultural resources, the park entered into an agreement with the American Indian Council of Mariposa County, Inc. in 1997 regarding the conducting of traditional activities in Yosemite National Park, and committed to consultation with all culturally associated American Indian entities under the 1999 Programmatic Agreement.

The Merced River Plan was developed to guide decision-making on proposed actions within the Merced River corridor by applying consistent decision-making criteria and management zone policies to development in this area. Although these guidelines include protection of cultural resources, they do allow for development that could result in adverse effects on traditional cultural resources.

Other planned projects (such as the Ecological Restoration of Flood-Damaged Campgrounds and the Eagle Creek Merced River Ecological Restoration) call for restoration of native vegetation, which could have a long-term, beneficial effect on traditional cultural resources.

Cumulatively, all of the projects would be expected to have a local, long-term, minor, adverse effect on traditional cultural resources. Alternative 2 would contribute to this minor adverse effect.

Impairment

Potential adverse effects associated with Alternative 2 are expected to be mitigated through mitigation measures developed in consultation with the culturally associated tribes in accordance with the 1997 Traditional Cultural Activities agreement and the 1999 Programmatic Agreement. This alternative would not impair park resources for future generations.

Cultural Landscape Resources, Including Historic Sites and Structures

Analysis

Because of the narrow Area of Potential Effect associated with the proposed activities, Alternative 2 would have little potential to adversely affect historic structures. There is a potential for direct and indirect impacts to specific elements of the Valley Loop Trail, which includes numerous historic bridges and other built features for non-motorized traffic. In particular, Alternative 2 proposes utility corridor development where segments of the Valley Loop Trail pass through the North Pines/Tenaya Creek area (along the proposed Tenaya Creek Campground Utility Corridor), Upper Pines Campground, Happy Isles area, and near Housekeeping Camp. It should be possible to avoid adverse impacts to these historic elements of the trail by marking them in advance of construction and making equipment operators aware of their presence and importance.

Potential impacts to the historic utility infrastructure of Yosemite Valley were discussed under Alternative 1. Direct impacts on the cultural landscape under Alternative 2 would be short-term and adequately addressed by the construction mitigation measures discussed in Chapter II.

Potential direct effects to cultural landscape resources (including historic sites and structures) are limited to The Ahwahnee area. 

The Ahwahnee. Construction of a new lift station directly west of The Ahwahnee may intrude on the visual elements of the hotel from vantage points to the west and south of the building. Similarly, the lift station may constitute an impact to the viewshed of the hotel, especially from the west doors of the Great Lounge, the windows in the Mural Room and the Solarium, and the second floor balcony above the Mural Room, as well as from the southwest facing windows of the dining room. These visual impacts may be both short- and long-term and potentially of moderate intensity. This impact will be mitigated by placing the lift station pumps and piping underground and screening the generator housing structure and lift station contols from these vantage points using vegetation or other means in keeping with the historic character of the area. The generator housing structure will be designed in compliance with the Ahwahnee area recommendations in the draft Design Guidelines for Yosemite Valley to ensure that the structure maintains the appropriate character of the area.

Camp 6/Cook’s Meadow.  Construction of either the originally proposed Alternative 2 or Route Option A would not affect cultural landscape resources in this area. 

Summary of Alternative 2 Impacts

Construction activities associated with Alternative 2 could result in direct and indirect effects to the Valley Loop Trail and The Ahwahnee. These adverse effects are expected to be local, short-term, and minor and should be appropriately mitigated through mitigation measures discussed in Chapter II.

Cumulative Impacts

Cumulative impacts to cultural landscape resources, including historic sites and structures, are based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley in combination with potential effects of this alternative. Past development, visitor use, and natural events have resulted in adverse cumulative impacts to historic resources and the cultural landscape. Over time, structures and sites such as homestead cabins, barns, road and trail segments, bridges, sawmill facilities, historic tourist facilities, blazes, and campsites have been affected. These resources are reminders of the Valley’s homesteading, grazing, and lumbering history as well as early tourism.

Reasonably foreseeable future actions that could affect historic and cultural landscape resources in the Valley include several proposals within the Yosemite Valley Plan. The Yosemite Valley Plan would result in the removal, relocation, or modification of historic buildings and structures, and the introduction of modern facilities and development within historic districts and contributing portions of the cultural landscape. The Yosemite Valley Plan also would restore native vegetation communities to patterns more in keeping with the cultural landscape and historic setting of the Valley. Overall, implementation of the Yosemite Valley Plan would adversely affect the cultural landscape.

Protection of cultural resources is an integral component of the Merced River Plan. The plan provides a framework for decision-making on future management actions within the Merced River corridor through the application of a consistent set of decision-making criteria and consideration of specific management elements. The plan would have a beneficial cumulative effect on cultural landscape resources, including historic sites and structures.

The cumulative projects in Yosemite Valley would result in a local, long-term, minor, adverse impact on historic resources and the cultural landscape due to the disturbance of such resources from planned development projects. Alternative 2 is not expected to substantially change the effect of cumulative projects, which are expected to result in local, long-term, negligible to minor, adverse impacts on these resources.

Impairment

Impacts associated with Alternative 2 are expected to be negligible to minor and are not expected to impair the park’s historic sites and structures or cultural landscape resources for future generations.

Section 106 Summary for Alternative 2

Under regulations of the Advisory Council on Historic Preservation (36 CFR 800.9) addressing the criteria of effect and adverse effect, the National Park Service finds that actions under this alternative would have the potential to adversely affect significant historic properties.  Some archeological sites may be at risk of disturbance during construction of proposed utility corridors and removal or abandonment of utilities in areas proposed for ecological restoration.  If archeological sites could not be avoided, monitoring and data recovery carried out in accordance with the 1999 Programmatic Agreement would retrieve important information from the disturbed resources, thereby avoiding adverse effects on most sites.  Proposed activities in the Tenaya Creek Campground Utility Corridor, however, have the potential to affect a large site that includes an area where human remains have been discovered.  Therefore, activities in this area could have an adverse effect.  To mitigate this adverse effect, a testing plan and discovery plan would be implemented in consultation with the State Historic Preservation Officer and the culturally associated American Indian groups. Construction of the Tenaya Creek Campground Utility Corridor will not proceed until the potential effects of activities in this area are appropriately mitigated.  Traditional cultural resources may also be disturbed during construction activities associated with utility corridor construction and utility removal and abandonment.  The park has developed mitigation measures through consultation with culturally associated American Indians to address adverse effects on these resources.  Activities proposed under Alternative 2 could also adversely affect cultural landscape resources, including historic sites, by construction activities near sites or the addition of a new facility.  Above ground structures will be minimized by placing transformers, pumps and piping underground.  New facilities will be sited and designed to screen the structures from important vantage points. 

In accordance with National Park Service policies and procedures, the park would continue to protect cultural resources to the greatest extent possible.  Disturbance of significant cultural resources would be avoided wherever possible, but in instances where avoidance or preservation could not be achieved, appropriate mitigation would be carried out under provisions of the 1999 Programmatic Agreement.

Social Resources

Scenic Resources

Analysis

Under Alternative 2, integrated utility corridors and associated infrastructure would be constructed in Yosemite Valley. This alternative also includes the reduction of utility crossings of the Merced River and its tributaries, and removal of utility infrastructure in areas identified for ecological restoration. The Merced River and adjacent meadows are included in the A scenic category, and most of the east Valley is within the A or B scenic categories, so construction activities would likely have short-term adverse effects on scenic resources. Alternative 2 would not impact landscape character, access to important viewpoints, or visibility of viewpoints in the long term. Because proposed utility corridors and related infrastructure would primarily be developed in areas that are already impacted by transportation or other facilities, this alternative is not expected to substantially change the amount of development visible from popular vantage points.

Construction activities would have localized, short-term, minor to moderate, adverse impacts on scenic Valley views from various vantage points. Although views of scenic features would not be obstructed, there is a potential for the visual intrusion of construction activities into the view.

Happy Isles. Construction of the utility corridor in the Happy Isles area is expected to have short-term, local, minor, adverse impacts to Valley views and views of scenic features due to the visual intrusion of construction activity. This alternative would not result in any long-term impact on the scenic resources of Yosemite Valley.

Campgrounds. Substantial utility construction is proposed in the Campgrounds area, primarily along roadways and within campground areas proposed for redevelopment. Construction activities in this area could have short-term, minor, adverse impacts to Valley views from some popular vantage points, such as Upper Yosemite Fall, Glacier Point, and Columbia Point. Construction activity in this area could also have effects on views of some scenic features, such as Half Dome, through intrusion of construction activity into the foreground or intermediate ground view. This would result in short-term, local, minor to moderate, adverse impacts to scenic resources.

Ecological Restoration Area. Substantial utility removals are proposed in the Ecological Restoration area. Construction activities would be visible from some popular vantage points and could have adverse effects on views of some scenic features, as discussed above. These impacts would be adverse and could be of moderate intensity but would be short-term related to construction activities.

The Ahwahnee. Construction of utility infrastructure proposed in The Ahwahnee area under Alternative 2 could be visible from some popular vantage points and could have adverse effects on views of some scenic features through intrusion of construction activity into the view.  In addition, a generator housing structure would be constructed in this area.  This structure will be sited and designed to minimize its visibility from roads, pathways, and other public areas, including from important vantage points around The Ahwahnee.  The structure will also be designed in accordance with the draft Design Guidelines for Yosemite Valley to ensure that it is in character with this historic area. Alternative 2 would result in short-term, local, minor to moderate, adverse impacts and long-term, local, minor, adverse impacts to scenic resources in this area.

Curry Village. Construction of the proposed corridors and related utility infrastructure in the Curry Village area could impact some Valley views in the short-term. These impacts would be expected to be local, short-term, minor, and adverse.

Housekeeping Camp. Construction of utility corridors and related infrastructure in this area would be visible from some popular vantage points (such as Sentinel Bridge) and have adverse effects on views of some scenic features through intrusion of construction activity into the view. This would result in short-term, local, moderate, adverse impacts to scenic resources.

Yosemite Village. Construction of proposed utility corridors and related infrastructure in the Yosemite Village area could also be visible from some popular vantage points and could have adverse effects on views of some scenic features through intrusion of construction activity into the view. In addition, a generator housing structure would be constructed to support the proposed Yosemite Village Transit Center Lift Station.  This structure would be sited and designed to minimize visibility from roads, trails, and other public areas, and would comply with the design recommendations in the draft Design Guidelines for Yosemite Valley.  This would result in short-term and long-term, local, minor, adverse impacts to scenic resources.

Camp 6/Cook’s Meadow. Alternative 2 proposes construction activities within the Camp 6/Cook’s Meadow area, including construction of a Merced River utility crossing. Construction of the utility corridor through this area could result in the removal of vegetation along the corridor. This loss of vegetation may be visible from high vantage points. Construction activities in this area could also be visible from some popular vantage points, including Sentinel Bridge, and could have adverse effects on views of some scenic features through intrusion of construction activity into the view. This would result in short-term, local, minor to moderate, adverse impacts to scenic resources.

Route Option A would not result in a change to the overall intensity of impacts to scenic resources in the Camp 6/Cook’s Meadow area. However, if Route Option A is implemented, there would be less of an impact to scenic resources due to the reduction of the number of mature oak trees affected by construction.

Summary of Alternative 2 Impacts

Alternative 2 would result in local, short-term, moderate, adverse impacts to highly valued scenic resources and local, long-term, minor, adverse impacts. Alternative 2 would not result in any long-term, adverse impact to scenic resources.

Cumulative Impacts

Cumulative impacts to scenic resources are based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley, in combination with potential effects of this alternative. The projects identified below include only those projects that could affect scenic resources within the Merced River corridor or the east Valley.

Scenic resources have been affected by numerous past actions since the inception of the park. Primary among these is the alteration of natural communities caused by Euro-American settlers who lived in the park. For example, agricultural activities and the development of tourism resulted in the drying out of the Valley by breaching the moraine and controlling naturally occurring fires, which affected vegetation patterns along the Merced River. Broad-leaved trees along the riverbanks were replaced by the comparatively dense stands of conifers that exist today. These events have resulted in a local, long-term, adverse effect on scenic resources, as the conifers now block views of visually important landscape features that were visible throughout the Valley before the vegetation patterns were changed.

Reasonably foreseeable future actions that would have a net beneficial cumulative effect on scenic resources include those that improve the general health of ecosystems along the Merced River corridor and within Yosemite Valley. The Merced River Plan prescribes the restoration of degraded areas of the Merced River corridor, resulting in beneficial impacts on A category scenic resources. Implementation of the Yosemite Valley Plan would restore riverside meadow areas and result in a net decrease in development within Yosemite Valley. These projects are expected to have a long-term, major, beneficial effect on the scenic resources in Yosemite Valley.

Reasonably foreseeable projects that would have an adverse effect on scenic resources include those Yosemite Valley Plan projects that would result in additional structures and infrastructure within the Valley, including Curry Village Employee Housing, Curry Village and East Yosemite Valley Campground Improvements, and Yosemite Lodge Area Redevelopment. The local, long-term, moderate, adverse effects of these reasonably foreseeable projects would be related to an increase in the amount of development visible in Valley views from popular vantage points, and the potential intrusion of new development areas into views of scenic resources within the Valley. For example, new development at Curry Village could increase the development density in the vicinity of the river and reduce the vegetative screening of the existing Curry Village complex.

The cumulative projects within the Valley would result in a local, long-term, major, beneficial cumulative impact on scenic resources in Yosemite Valley because of the overall emphasis on restoring disturbed or developed land to natural conditions within A category scenic areas and improving the health of ecosystems within Yosemite Valley.

Alternative 2 and the cumulative projects in Yosemite Valley would result in a local, long-term, major, beneficial impact on scenic resources in Yosemite Valley. This is due to the overall emphasis on restoring disturbed or developed land to natural conditions and improving the health of ecosystems within Yosemite Valley. The long-term beneficial effects on highly valued scenic resources associated with the restoration projects proposed in the Yosemite Valley Plan would outweigh the short-term, adverse effects associated with construction activities associated with Alternative 2.

Impairment

Alternative 2 would result in short-term, minor to moderate, adverse impacts to scenic resources due to the visual intrusion of construction activities into scenic views. No long-term impacts to scenic resources are anticipated and the park’s highly valued scenic resources would not be impaired for future generations.

Visitor Experience and Recreational Resources

Analysis

Alternative 2 is not expected to result in any long-term effects to recreational resources or visitor experiences. Access to recreation areas for hiking, swimming, fishing, and other activities may be impacted temporarily during construction activities. Sightseeing by car or bus could be affected by temporary changes in traffic circulation and access. Passive recreation activities could also be disrupted by the noise and visual intrusion of construction activities.

Recreational impacts would be minimized by developing a Visitor Communication and Protection Plan to ensure that visitors are safely and efficiently routed around construction areas. This plan would include means for communicating construction and closure schedules to the public, adequate barriers to keep visitors clear of active construction areas, and clear signage to direct visitors to open park destinations during construction. Construction activities would have a local, short-term, minor to moderate, adverse effect on recreation activities and visitor experience near construction sites.

Happy Isles. Construction of the proposed utility corridor in this area could result in short-term access changes to the Happy Isles Nature Center and nearby areas. Since construction activities in this area would occur on the west side of the Merced River, it would not be expected to limit access to the main trails on the east side of the Merced River. However, if the Happy Isles Footbridge is replaced to provide access to the John Muir Trail from Happy Isles, construction activity in this area could have a short-term impact on access to this trail. Construction activity on the western side of the river could also have a short-term, adverse effect on the recreational experience of park visitors using the trails on the east side of the river. In addition, construction may result in short-term changes to roadway circulation and access that could adversely affect sightseeing by bus. Overall, construction is expected to result in a local, short-term, minor to moderate, adverse effect on visitor experience and recreation in this area.

Campgrounds. Construction of utility corridors within the east Valley campgrounds would result in short-term, local, moderate, adverse effects on the recreation experience in the areas adjacent to the campgrounds, including Stoneman Meadow and trails near Tenaya Creek. Construction in these areas would be coordinated with redevelopment of flooded campgrounds in the east Valley. Construction activities in these areas could have local, short-term, moderate, adverse effects on camping and could have local, short-term, moderate effects on visitor experience for visitors hiking in the vicinity. Construction of the new utility corridor along the Happy Isles Loop Road could also have a short-term impact on visitor sightseeing by bus due to temporary road closures. Overall, construction in this area is expected to have a local, short-term, moderate, adverse effect on visitor experience and recreation.

Ecological Restoration Area. Construction and utility removal activities in this area would be coordinated with proposed ecological restoration activities. Construction activities in this area could impact visitor experiences associated with hiking and sightseeing along local trails and near Stoneman Bridge. Construction activities could result in local, adverse effects on the recreation experience for sightseers traveling by bus or car, particularly during the removal of Merced River utility crossings near Stoneman Bridge. Overall, construction in this area is expected to have a local, short-term, moderate, adverse effect on visitor experience and recreation

The Ahwahnee. Proposed utility corridor and utility infrastructure construction in The Ahwahnee area, including removal actions in Ahwahnee Meadow, could result in local, short-term, minor to moderate, adverse effects on visitor experience and recreation for visitors staying at The Ahwahnee or traveling by foot or vehicle through this area.

Curry Village. Construction of proposed utility infrastructure in the Curry Village area would have a local, short-term, minor to moderate, adverse effect on visitor experience and recreation for visitors trying to access facilities in Curry Village during construction of these corridors.

Housekeeping Camp. Utility infrastructure construction and removals in Housekeeping Camp could result in local, short-term, minor, adverse effects related to access along Southside Drive for sightseeing by vehicle. In addition, construction noise and activity is likely to adversely affect recreational experiences for other visitors in the general vicinity. Overall, construction in this area is expected to have a local, short-term, minor to moderate, adverse effect on visitor experience and recreation.

Yosemite Village. Construction of utility corridors and infrastructure in this area could have local, short-term, moderate, adverse effects on sightseers due to potential changes in traffic circulation within Yosemite Village and on Northside Drive. Noise and other construction impacts would be expected to result in local, short-term, moderate, adverse effects on visitor experience and recreation in this area.

Camp 6/Cook’s Meadow. Construction activities in this area could result in short-term restrictions on traffic circulation as repairs are constructed along Southside Drive and near the northern portion of Sentinel Drive. Noise and other construction impacts would be expected to result in short-term, adverse effects on visitor experiences in this area. Overall, construction in this area is expected to have a local, short-term, moderate, adverse effect on visitor experience and recreation.

Route Option A would not result in a change to the overall impacts to visitor experience and recreation resources in the Camp 6/Cook’s Meadow area.

Summary of Alternative 2 Impacts

Alternative 2 would result in local, short-term, minor to moderate, adverse impacts on recreational activities and the quality of visitor experiences near construction sites. Alternative 2 would not result in any long-term, adverse effects on recreational resources or visitor experiences.

Cumulative Impacts

Cumulative impacts on visitor experience and recreation are determined based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley in combination with potential effects of this alternative. The projects identified include only those actions that could affect visitor experience and recreation in Yosemite Valley.

Examples of reasonably foreseeable future actions that could have a beneficial cumulative effect on visitor experience and recreational opportunities include projects proposed under the Yosemite Valley Plan, such as development of a new visitor center in Yosemite Village, expanded transit service distributing visitors to more park destinations, and expansion of campgrounds in Yosemite Valley. Other reasonably foreseeable projects that could have a beneficial cumulative effect on recreation include the following: Happy Isles to Vernal Fall Trail Reconstruction, Discovery View Scenic Overlook Vault Toilet Installation, Rehabilitate Yosemite Valley Campground Restrooms, Eagle Creek Merced River Ecological Restoration (Yosemite Valley), Lower Yosemite Fall Project, and the Shuttle Bus Replacement Project. These projects could result in short-term disruptions of recreational activities due to construction, but in the long-term, they would provide expanded recreational opportunities in Yosemite Valley and improved transit service distributing visitors to more park destinations.

The Merced River Plan would have a beneficial cumulative effect on visitor experience and recreation in Yosemite Valley by protecting and enhancing a spectrum of recreational opportunities available in the Valley. In addition, the management zoning prescribed under the Merced River Plan provides for various types of recreation, from opportunities for solitude to interactive and group-based recreational activities.

The cumulative projects would have a local, long-term, moderate, beneficial effect on visitor experience and recreation due to expanded recreational opportunities in Yosemite Valley and improved transit service distributing visitors to more park destinations. Alternative 2 would reduce these beneficial effects in the short-term but should not have any long-term effect on visitor experience and recreation. Therefore, the cumulative projects combined with Alternative 2 are still expected to have a local, long-term, moderate, beneficial effect on visitor experience and recreation.

Conclusions

Construction activities related to Alternative 2 would result in local, short-term, minor to moderate, adverse impacts to recreational activities and visitor experiences. No long-term adverse impacts on recreational resources or visitor experiences are expected.

Impairment

Alternative 2 would result in local, short-term, minor to moderate, adverse impacts on recreation activities near construction areas. Alternative 2 is not expected to impact the diversity or quality of recreational opportunities in Yosemite Valley for the long term. Therefore, Alternative 2 would not impair the park’s recreational resources for future generations.

Park Operations and Facilities

Transportation

Analysis. Alternative 2 would not result in any long-term effects on roadways, traffic volume and circulation, or traffic safety. Traffic volumes on access roads to the Valley could experience temporary increases in volume related to movement of construction workers and materials to construction sites. Construction of proposed utility corridors and associated utility infrastructure in various areas would also require temporary closures of various roads and trails. Road closures associated with construction activity would affect traffic circulation and could result in traffic delays. A Visitor Communication and Protection Plan would be required to ensure that visitors are safely and efficiently routed around construction areas. Alternative 2 is expected to have local, short-term impacts on traffic volumes, circulation, and safety related to construction activities.

Happy Isles. Construction of the proposed utility corridor in the Happy Isles area would primarily affect a park access road to the water storage tank. Construction of the portion of the corridor that crosses Happy Isles Loop Road could result in local, short-term, minor, adverse impacts to traffic circulation in that area. Since the transportation facilities that would be affected are not major public roadways, the adverse effects on transportation in this area are expected to be local, short-term, and minor.

Campgrounds. Alternative 2 construction activities in the Campgrounds area would affect Happy Isles Loop Road and access roads within the Upper and Lower Pines Campgrounds. Construction of these improvements is planned to be coordinated with redevelopment of these campground areas. Construction efforts in this area would impact public access to these campgrounds. The adverse effects on traffic circulation and safety in this area are expected to be local, short-term, and minor during the construction period.

Ecological Restoration Area. Proposed construction and removal actions within this area are proposed to be coordinated with proposed ecological restoration activities. These restoration efforts are expected to include removal of Northside Drive from Upper and Lower River Campgrounds and Ahwahnee Meadow. It is expected that traffic circulation changes proposed in the Yosemite Valley Plan to allow two-way traffic on Southside Drive to Curry Village will have been implemented prior to the construction activities in this area proposed under Alterantive 2. Based on this assumption, construction associated with Alternative 2 would have local, short-term, negligible, adverse impacts to traffic circulation and safety in this area.

The Ahwahnee. Construction of the Ahwahnee Road Utility Corridor would require excavation of the existing road and would likely result in having only one lane available for traffic to access The Ahwahnee area during the construction period. This would result in local, short-term, moderate, adverse effects on traffic circulation and safety in The Ahwahnee area.

Curry Village. Proposed utility corridor and utility infrastructure development in the Curry Village area could affect traffic circulation during construction activities. Construction of the Southside Drive Utility Corridor under Southside Drive would result in temporary closure of Southside Drive. Traffic would be routed to the Curry Village area by converting Northside Drive to two-way traffic between Sentinel Road and Stoneman Bridge. This would result in short-term, moderate, adverse effects on traffic circulation, delays, and safety. The Curry Village Utility Corridor and removal of the existing water corridor in this area are expected to be coordinated with other proposed construction efforts related to realignment of Curry Village Road from Southside Drive to the east Valley campgrounds, and removal of Southside Drive from Stoneman Meadow, as proposed in the Yosemite Valley Plan. Overall, these construction activities would be expected to have local, short-term, moderate effects on transportation circulation, delays, and safety.

Housekeeping Camp. Construction of the portion of Southside Drive Utility Corridor within the Housekeeping Camp area would have the same short-term, adverse effects on traffic circulation and safety as discussed above for Curry Village. Construction of the facilities within Housekeeping Camp itself would have a local, short-term, minor, adverse effect on traffic circulation, delays, and safety in this area.

Yosemite Village. Construction of the Northside Drive Utility Corridor would require a temporary closure of Northside Drive with traffic routed into and out of Yosemite Valley on Southside Drive. Construction of other utility corridors in the Yosemite Village area would also temporarily impact traffic circulation, delays, and safety on Yosemite Village Drive and other local Village roads. The effects of the temporary traffic circulation changes in this area would be local, short-term, moderate, and adverse.

Camp 6/Cook’s Meadow. Construction of the Merced River Crossing Utility Corridor could require temporary closures on Southside Drive near Housekeeping Camp and on Sentinel Drive. These closures would result in short-term, local, minor to moderate, adverse impacts on traffic circulation, delays, and safety in Yosemite Valley.

Route Option A would not result in a change to the overall impacts to transportation in the Camp 6/Cook’s Meadow area.

Summary of Alternative 2 Impacts. Alternative 2 is expected to result in local, short-term, minor to moderate, adverse effects on transportation volume, circulation, delays, and safety within Yosemite Valley during construction activities. These impacts would be minimized and mitigated through development of a Visitor Communication and Protection Plan prior to start of construction.

Cumulative Impacts. Cumulative effects on transportation facilities, traffic circulation, and safety are based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley in combination with the potential effects of this alternative. The extent to which past, present, or reasonably foreseeable future projects could have a cumulative effect, when combined with this alternative, is determined largely by whether such projects would affect transportation facilities or traffic circulation within Yosemite Valley.

Past, present, and reasonably foreseeable projects that could have a long-term beneficial effect on transportation include implementation of the Yosemite Valley Plan and YARTS. Since 1950 the population of California has tripled, and the rate of increase in vehicle-miles-traveled has increased six-fold. Transportation conditions within the park have been influenced by this surge in population growth. In the 1980s, a Restricted Access Plan was developed for use when traffic and parking conditions in Yosemite Valley are overcongested. The plan has the effect of reducing the number of incoming vehicles until the traffic volume and parking demand in Yosemite Valley decrease sufficiently (as visitors leave the Valley) to stabilize traffic conditions, resulting in a long-term, major, beneficial impact to traffic flow on El Portal Road and Big Oak Flat Road.

The Yosemite Valley Plan proposes to enhance the quality of the visitor experience in Yosemite Valley by reducing automobile congestion and limiting crowding. It also proposes traffic management systems and options for the sizing and placement of parking lots, both within and outside of Yosemite Valley. Parking lot(s) outside the Valley could be used to intercept day visitors and shift those visitors to Valley-bound shuttle buses. Implementation of the Yosemite Valley Plan would result in a substantial decrease in traffic volumes and a major improvement in traffic flow within Yosemite Valley and particularly on El Portal Road between its intersection with Big Oak Flat Road and Pohono Bridge. Therefore, the Yosemite Valley Plan would result in a local, long-term, major, beneficial impact to traffic flow, access and circulation, and transportation safety conditions along the Merced River corridor and in Yosemite Valley.

Construction of some of the reasonably foreseeable future projects planned or approved within the Merced River corridor, such as the Curry Village Employee Housing, Lower Yosemite Fall Project, and Yosemite Lodge Area Redevelopment projects, could result in short-term, adverse impacts on transportation. The adverse effects of these projects would be localized and short-term in nature, and primarily related to construction-generated traffic on roadways serving the project sites. Construction activities would increase traffic on local roadways, both from equipment and material haul trips and commute trips by construction workers. Some construction projects could also result in trip delays. The intensity of the adverse effects from the construction-related traffic would range from minor to moderate, depending on which, if any, of the construction projects occurred simultaneously. Activities related to the construction of the reasonably foreseeable projects would result in a local, short-term, minor to moderate, adverse impact to traffic flow.

Collectively, the cumulative projects discussed above would have a local, long-term, major, beneficial impact on transportation conditions along the Merced River corridor. Construction activities associated with the development of cumulative projects, however, would reduce the intensity of this beneficial impact to a minor or moderate level in the short term. Alternative 1 and the cumulative projects would result in a local, long-term, moderate, beneficial impact on transportation conditions along the Merced River corridor. Construction activities associated with the development of cumulative projects, however, would reduce the intensity of this beneficial impact to a minor or moderate level in the short term. Construction impacts to traffic circulation under Alternative 2 would contribute to reducing the beneficial effects on transportation to a negligible level in the short term.

Conclusions. Alternative 2 would result in local, short-term, minor to moderate, adverse impacts to traffic volumes, circulation, delays, and safety. No long-term, adverse impacts on traffic volume, circulation, delays, or safety are expected.

Impairment. Alternative 2 would not have a long-term, adverse effect on traffic volume, circulation, or safety in Yosemite Valley and is not expected to impair park resources for future generations.

Park Operations

Analysis. Alternative 2 proposes consolidation of utility infrastructure into integrated corridors primarily located outside of floodplains, riverbanks, and other sensitive areas. Consolidation of utility infrastructure and the reduction of Merced River crossings would have a minor, beneficial effect on park operations. Alternative 2 would, however, result in an increased number of lift stations and electric transformers, which could result in increased operations and maintenance costs for the park. Overall, Alternative 2 would result in a local, long-term, negligible to minor, adverse effect on park operations from increased costs.

If Route Option A is implemented, there would be no change in impacts to park operations.

Summary of Alternative 2 Impacts. Alternative 2 would have local, long-term, negligible to minor, adverse impacts on park operations.

Cumulative Impacts. Cumulative effects on park operations and facilities are based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley in combination with potential effects of this alternative. The extent to which past, present, or reasonably foreseeable future projects could have a cumulative effect, when combined with this alternative, is determined largely by whether such projects would affect park facilities or the demand for park operations services and facilities. Projects that affect park facilities themselves or the demand for facilities management, resource management, and maintenance of utility systems services in particular would have the potential for cumulative effects with the proposed project.

Park operations and facilities have been affected by numerous past National Park Service management decisions and projects since the inception of the park. Recent past projects include Cook’s Meadow Ecological Restoration, Happy Isles Gauging Station Bridge Removal, the Merced River Plan, and implementation of the Yosemite Valley Plan. Overall, there is no net adverse or beneficial effect of these past actions on park operations and facilities.

Reasonably foreseeable future actions that would have a beneficial cumulative effect on park operations and facilities are those that could reduce the number of visitors entering the park, reduce the number or amount of facilities within the park, or reduce long-term maintenance activities. An example is the Replacement/Rehabilitation of the Yosemite Valley Main Sewer Line. Although this project would have short-term, adverse effects associated with planning, construction, replacement, and rehabilitation, its overall effect would be to reduce long-term maintenance. Therefore, this project would have a long-term, beneficial cumulative impact on park operations and facilities.

Examples of reasonably foreseeable projects that would have an adverse effect on park operations and facilities are the Merced Wild River Plan and the Yosemite Valley Plan. Implementation of these plans would substantially increase demand on park operations and facilities in the short term during planning, repair, rehabilitation, construction/demolition, and replacement of facilities (e.g., removal of the road through Stoneman Meadow, construction of new campsites, and restoration of large areas of Yosemite Valley to natural conditions). Implementation of these plans is expected to have local, short- and long-term, moderate to major, adverse impacts on park operations and facilities.

Overall, the past, present, and reasonably foreseeable future actions would have local, moderate, adverse cumulative impacts because of the increased demand on park operations, services, and facilities over both the short and long term. Alternative 2 is not expected to substantially change this cumulative effect.

Conclusions. Alternative 2 would result in local, long-term, negligible to minor, adverse impacts on park operations and facilities, related to increased utility infrastructure. These costs may be offset somewhat by reduced costs associated with fewer river and creek utility crossings to be maintained.

Impairment. Although implementation of Alternative 2 would result in local, long-term, negligible to minor, adverse effects on park operations, the expected increase in costs would not be expected to impair park resources for future generations.

Socioeconomics

Analysis

Alternative 2 calls for the development of consolidated utility corridors and utility facilities, as well as the removal of utility infrastructure in areas identified for ecological restoration. It also includes most of the immediate repairs required to comply with the California Regional Water Quality Control Board Cleanup and Abatement Order. Alternative 2 would result in $75.8 million in direct spending on materials, labor, and equipment. Typically, design and engineering costs are spent outside of the region and can account for up to 25% of the total estimated project cost. In addition, a significant portion of construction costs also may be spent outside the region. It was estimated that approximately 50% of the total $75.8 million would be spent within the three-county region of Mariposa, Madera, and Tuolumne Counties.

In addition to the expected $37.9 million in direct expenditures within the region, the construction expenditures would result in secondary and induced effects within the economy as the construction dollars are spent by businesses and households. Secondary and induced impacts for this alternative were estimated at $89.3 million of economic output in the region, including $28.8 million in earnings to households and creation of 815 jobs in the regional economy. Based on 2000 economic data presented in Chapter III, the changes in economic output and employment would represent an increase of 1% over existing conditions. This would not likely result in any discernible effect on the social and economic environment of the region. Therefore, construction expenditures related to this alternative would have a short-term, negligible, beneficial impact on the regional economy.

If Route Option A is implemented, there would be no change in impacts to socioeconomics.

Summary of Alternative 2 Impacts

Alternative 2 would result in regional, short-term, negligible, beneficial effects on the regional economy due to direct expenditures and the secondary benefits associated with increased construction expenditures.

Cumulative Impacts

Cumulative socioeconomic impacts discussed herein are based on analysis of reasonably foreseeable future actions in the region in combination with potential effects of this alternative. The cumulative projects that follow are those relevant to the regional economy.

Reasonably foreseeable future projects at Yosemite National Park that could have a beneficial cumulative effect on the regional economy are related to construction activity, including the Curry Village Employee Housing, Eagle Creek Merced River Ecological Restoration, Ecological Restoration of Flood-Damaged Campgrounds, the El Portal Road Improvement Project (from Cascades Diversion Dam to Pohono Bridge), Cascades Dam Removal, Happy Isles Fen Habitat Reclamation Project, Happy Isles Gauging Station Bridge Removal, Happy Isles to Vernal Falls Trail Reconstruction, Curry Village and East Yosemite Valley Campground Improvements, Lower Yosemite Fall Project, Replacement/Rehabilitation of Yosemite Valley Main Sewer Line, Yosemite Lodge Area Redevelopment, and Yosemite Valley Shuttle Bus Stop Improvements. Private development projects such as the Yosemite Motels Expansion just outside of the park entrance at El Portal and other facilities constructed under the Mariposa County General Plan Update would also result in short-term spending in the construction sector.

The cumulative planning, transportation, facility improvement, and development-related projects identified would generate construction-related output, employment, and income in the regional economy. Construction spending associated with the cumulative projects would also generate secondary output impacts as a result of local spending on materials and wages. Some of this construction-related spending would be expected to occur outside of the affected region.

The total construction-related spending in the affected region associated with the cumulative projects would have a short-term, major, beneficial impact on the regional economy resulting from the substantial and highly noticeable increase in construction output, income, and employment in the three-county region. The increase in construction-related output would be highly noticeable when compared with the total output of the construction industry in the affected region.

Some projects would increase the amount of visitor overnight accommodations in or near the park, including the Curry Village and East Yosemite Valley Campground Improvements, Yosemite Lodge Area Redevelopment, and Yosemite Motels Expansion. Increased overnight accommodations from these projects would result in a beneficial impact to employment, output, and taxable retail sales over the long term. The effect of this increase would be negligible because the total increase in overnight accommodations would not be substantial in comparison to existing accommodations. Therefore, cumulative actions would result in a local, long-term, negligible, beneficial impact to the regional economy. Since Alternative 2 would result in additional regional, short-term, beneficial effects on the economy and would support the implementation of projects proposed under the Yosemite Valley Plan, the effect of Alternative 2 and the cumulative projects would be long-term, negligible, and beneficial for the regional economy.

Impairment

The National Park Service has a management responsibility to conserve the scenery, natural and historic objects, and wildlife resources of the park. Socioeconomic resources are not subject to the impairment standard.

 

Alternative 3: East Yosemite Valley Utilities Improvement Plan with Merced River Crossing near Sentinel Bridge

Under Alternative 3, an East Yosemite Valley Utilities Improvement Plan with a Merced River utility crossing near Sentinel Bridge would be implemented. Under this alternative, the park would develop consolidated utility corridors following existing utility lines or existing or proposed transportation corridors. Alternative 3 would also reduce utility infrastructure within the Merced River and its floodplain from areas identified for ecological restoration in the Yosemite Valley Plan. Alternative 3 would also ensure efficient utility service to new facilities proposed under the Yosemite Valley Plan.

Alternative 3 also includes wastewater projects currently planned and required by the California Regional Water Quality Control Board to address recent wastewater releases. Those projects currently planned that could be eliminated with implementation of the East Yosemite Valley Utilities Improvement Plan have been removed from the Alternative 3 analysis.

Natural Resources

Soils

Analysis

Alternative 3 would result in a similar reduction in the total miles of utility infrastructure in Yosemite Valley through consolidation of utility lines into integrated corridors. Alternative 3 would result in short-term, adverse effects on soils in Yosemite Valley due to construction activities, including removal of utility facilities in environmentally sensitive areas identified for ecological restoration.  Utility removals in these areas are expected to allow the restoration of more natural subsurface water flows, enhancing highly valued hydric soils.Impacts to soils associated with Alternative 3 are summarized in table IV-10. Alternative 3 proposes the same activities as Alternative 2 in the Happy Isles, Campgrounds, Ecological Restoration, The Ahwahnee, Curry Village, Housekeeping Camp, and Yosemite Village areas. Impacts to soils would be the same as discussed under Alternative 2. Impacts would differ under Alternative 3 in the Camp 6/Cook’s Meadow area.

Camp 6/Cook’s Meadow. The proposed utility corridor would disturb approximately 11.3 acres of land in this area, including 5.4 acres of highly valued soils, 1.7 acres of resilient soils, and 4.2 acres of other soils. This would result in local, long-term, negligible to minor, adverse effects to soils.

Removal activities in this area would include the removal of the existing exposed wastewater crossing in Yosemite Creek and the pipe bursting and abandonment of the wastewater line that crosses Cook’s Meadow and the Camp 6 area. The removal actions in this area could impact up to 8.7 acres of highly valued soils. The removals and abandonments would result in local, short-term, moderate effects on highly valued soils, but would result in local, long-term, moderate, benefits related to restoration of more natural hydrologic and biologic processes in Yosemite Creek and in Cook’s Meadow.

Soil Impacts Associated with Alternative 3

 

^{a   Includes repairs to existing wastewater lines as described in Alternative 1, as well as construction of proposed consolidated utility corridors.}

The areas that would be affected are primarily within existing corridors that have been previously disturbed and developed. Impacts to soils in construction and removal areas are expected to be similar to those described for the Happy Isles area under Alternative 2 and would be mitigated through use of measures discussed in that subsection.

Summary of Alternative 3 Impacts

Implementation of Alternative 3 would result in short-term disturbance of up to 218 acres of soils, the vast majority of which have been previously disturbed. Construction and repair activities proposed under Alternative 3 would disturb up to approximately 118.2 acres of soils, of which approximately 27 acres are highly valued soils, 62.2 acres are resilient soils, and 29 acres are classified as other soils. These construction activities would have local, short- and long-term, major, adverse effects on highly valued soils and local, short- and long-term, moderate, adverse effects on other soils. These impacts would be mitigated through the implementation of Best Management Practices to minimize spills, soil compaction, and soil erosion; soil salvage and reuse, particularly in highly valued soil areas; and use of  trench plugs where needed to minimize changes to subsurface water flows. Implementation of these mitigation measures is expected to reduce short and long-term adverse impacts to soils to a minor level.

Removal and abandonment actions are expected to affect up to 99.5 acres of soils, including 77.1 acres of highly valued soils, 17 acres of resilient soils, and 5.4 acres of other soils. Although these actions would have local, short-term, major, adverse effects on highly valued soils, the long-term effects are expected to be local, major, and beneficial for highly valued soils. Removal actions are anticipated to have local, short-term, negligible to minor, adverse effects on other soils, but to result in local, long-term, negligible to minor benefits to these soils.

Overall, implementation of Alternative 3 is expected to result in local, short and long-term, minor, adverse effects on highly valued soils but local, long-term, major, beneficial effects on these previously disturbed soils. Effects on other types of soils are expected to be local, minor,  and adverse in the short-term and local, minor to negligible, and beneficial in the long-term.

Cumulative Impacts

The cumulative projects would result in local, long-term, minor, beneficial cumulative impacts to soil resources as discussed under Alternative 2. Alternative 3 would enhance the soil benefits from identified ecological restoration activities by removing utility infrastructure from the riverbed, riverbanks, and wet meadow areas. Alternative 3 and the cumulative projects would have a local, long-term, minor, beneficial impact to soils from restoration activities.

Impairment

Alternative 3 would result in local, short-term, adverse effects on highly valued soils, but provide for local, long-term, beneficial effects on highly valued soils related to the removal of utilities from highly sensitive areas and the restoration of more natural subsurface water flows in these areas.  Alternative 3 would also facilitate the ecological restoration activities proposed in the Yosemite Valley Plan. This alternative would not impair the soil resources of the park.

Hydrology, Floodplains, and Water Quality

Analysis

Alternative 3 proposes development of integrated utility corridors located along existing or proposed transportation corridors or existing utility locations. This alternative would also result in a reduction in the total length of utility lines, river and creek utility crossings, and utility infrastructure within the floodplain. Proposed lift stations and electric transformers to be constructed within the floodplain would be submersible to reduce the potential for adverse effects from flood events.

Impacts associated with Alternative 3 would be the same as those described for Alternative 2 for all subareas except for Camp 6/Cook’s Meadow.

Camp 6/Cook’s Meadow. The Camp 6/Cook’s Meadow area includes the Merced River crossing of the major utility corridor for the east Valley. Impacts from construction activities in the Merced River would include local, short-term, minor to moderate, adverse effects to river flow and water quality associated with the temporary diversion of water required during the excavation of the riverbank and riverbed for construction of the utility corridor. The use of heavy equipment in the river could result in accidental releases of fuels or other hazardous substances and could potentially impact water quality.

All proposed facilities in this area lie within the floodplain; however, the facilities are proposed to be placed underground and would not adversely affect the floodplain’s ability to accommodate flood flows.

Construction impacts would be minimized by limiting work within the river to low water periods, minimizing the disturbance area on the bank and riverbed, salvaging riverbed materials for replacement after construction, returning the riverbed to its pre-existing contour, and implementing Best Management Practices during construction to minimize the potential for water quality impacts associated with accidental spills or soil erosion. In addition, the park will mitigate water quality and hydrology impacts related to the proposed new Merced River utility crossing by implementing directional drilling for the river crossing if found to be technically and economically feasible.

Summary of Alternative 3 Impacts

Alternative 3 proposes development of consolidated utility corridors and removal of utilities from environmentally sensitive areas. This includes construction of a new integrated utility corridor proposed to cross the Merced River just east of Sentinel Bridge. Construction of utility repairs and new utility corridors is expected to result in local, short-term, minor to moderate, adverse effects on hydrology and water quality. Alternative 3 would also result in local, long-term, minor, beneficial effects on hydrology and water quality related to the reduced number of facilities within the river- and creekbeds and adjacent sensitive areas. Alternative 3 would have local, long-term, negligible effects on the floodplain.

Cumulative Impacts

The cumulative effects discussion for Alternative 3 is the same as that included earlier in this chapter for Alternative 2. The past, present, and future projects in Yosemite Valley, considered cumulatively with Alternative 3, would have a local, short-term, minor, adverse effect on hydrologic processes and water quality associated with construction disturbance. The cumulative projects together with Alternative 3 would have a local, long-term, negligible, beneficial effect on hydrologic processes, floodplains, and water quality in Yosemite Valley.

Impairment

Alternative 3 would result in local, short-term, minor to moderate, adverse effects to hydrologic processes and water quality associated with construction and removal actions proposed under this alternative. Alternative 3 would have local, long-term, minor, beneficial effects on the free flow of the Merced River due to reduced utility infrastructure within the river and the floodplain. Since adverse effects are expected to be short-term, minor to moderate, and localized, Alternative 3 would not impair the hydrologic resources of Yosemite Valley.

Wetlands

Analysis

Alternative 3 would result in short-term, adverse effects on wetland and aquatic habitats in Yosemite Valley due to construction activities; however, most of the areas proposed for utility corridor construction have been previously disturbed by utilities, transportation facilities, or other development. Implementation of Alternative 3 would remove utility infrastructure in areas where ecological restoration is proposed  Removal of utilities in these wetland areas would allow for more natural subsurface water flows throughout the wetlands and between the wetlands and river.

Impacts associated with Alternative 3 are summarized in table IV-11. Alternative 3 proposes the same actions as Alternative 2 in the Happy Isles, Campgrounds, Ecological Restoration, The Ahwahnee, Curry Village, Housekeeping Camp, and Yosemite Village areas and would have the same effects as described for Alternative 2. Impacts under Alternative 3 would be different than Alternative 2 in the Camp 6/Cook’s Meadow area.

Wetland and Aquatic Habitats Potentially Affected by Alternative 3

 

^{a   Includes repairs to existing wastewater lines as described in Alternative 1, as well as construction of proposed consolidated utility corridors.}

Camp 6/Cook’s Meadow. There would be no permanent reduction in the size of wetland and aquatic habitats in the Camp 6/Cook's Meadow area related to construction or removal activities. Construction of the proposed utility corridor and utility repairs are expected to have localized, short-term, adverse, construction-related impacts to 0.93 acre of wetland and aquatic habitats, which include riverine upper perennial, palustrine forest, and palustrine emergent. Construction activities may also have localized, long-term, adverse impacts on palustrine forest wetland habitat if the removal of trees are necessary within these areas. These short-term and long-term impacts can be mitigated to a minor level using mitigation measures discussed below.  The construction of and continued presence of utility infrastructure within wetland and aquatic habitats in the Camp 6/Cook's Meadow area could have long-term, minor, adverse effects on the hydrology of these habitats by impeding the natural subsurface water flows within wetland areas and between the river and adjacent wetlands.

In the Camp 6/Cook's Meadow area, approximately 1.82 acres of wetland and aquatic habitats, including riverine upper perennial, palustrine forest, and palustrine emergent would be affected by removal and abandonment activities. Removal and abandonment activities are expected to have localized, short-term, minor, adverse effects on wetland and aquatic habitats, but are expected to result in local, long-term, minor, beneficial impacts to wetland and aquatic habitats through restoration of more natural subsurface water flows through the area. Removal activities may also have localized, long-term, minor, adverse impacts on palustrine forest wetland habitat due to the potential for a limited loss of trees within the areas.

The areas that would be affected are within existing corridors that have been previously disturbed and developed. Effects to wetland and aquatic habitats would be related to heavy equipment and construction activities and could include soil disturbance and compaction, dust, vegetation removal, root damage, erosion, and introduction and spread of non-native species. The addition of silt, the resuspension of sediment, or the introduction of pollutants (i.e., fuels or lubricants) related to construction activities could degrade the quality of native wetland and aquatic habitats in the immediate vicinity of construction activities. The application of mitigation measures described in Chapter II, specifically those related to protection of wetland areas, minimization of disturbance areas, stormwater management measures, and spill prevention and pollutant control would reduce the potential short-term, adverse impacts to wetland and aquatic habitats to a minor intensity.

Summary of Alternative 3 Impacts

There would be no permanent reduction in the size of wetland and aquatic habitats related to construction or removal activities associated with Alternative 3. Under Alternative 3, construction of integrated utility corridors and existing utility repairs are expected to have localized, short-term, adverse, construction-related impacts to 4.99 acres of wetland and aquatic habitats. Removal and abandonment activities are expected to have localized, short-term, adverse, construction-related impacts to 20.12 acres of wetland and aquatic habitats. The areas that would be affected are within existing corridors that have previously been disturbed and developed. The combined impact to wetland resources over the entire project area may result in short-term impacts of minor to moderate intensity. The construction of and the continued presence of utility infrastructure within wetland and aquatic habitats could have long-term, minor, adverse effects on the hydrology of these habitats by impeding the natural subsurface water flows within wetland areas and between the river and adjacent wetlands. Construction activities may also have localized, long-term, minor, adverse impacts on palustrine forest wetland habitat if the removal of trees are necessary within these areas.

Construction impacts would be mitigated through the application of mitigation measures described in Chapter II, specifically those related to protection of wetland areas, minimization of disturbance areas, and prevention of spills. Consolidation of utility infrastructure in major developed corridors, removal of utilities from environmentally sensitive areas, and restoration of more natural subsurface water flows in wetland areas are expected to have local, long-term, minor to moderate, beneficial effects on wetland resources.

Cumulative Impacts

Cumulative impacts to wetland and aquatic resources based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley were discussed under Alternative 2. The cumulative projects evaluated would result in a local, long-term, moderate, beneficial effect on wetlands within Yosemite Valley due to wetland restoration efforts. Alternative 3 would enhance the cumulative benefits from ecological restoration activities by removing utility infrastructure from the riverbed, riverbanks, and wet meadow areas identified for ecological restoration.

Impairment

Alternative 3 would result in local, short-term, minor to moderate, adverse effects on wetland and aquatic resources but provide for local, long-term, moderate, beneficial effects on wetland and aquatic resources directly by the removal of utilities from highly sensitive areas and the restoration of more natural subsurface water flows in those areas. Alternative 3 would also facilitate implementation of ecological restoration activities proposed in the Yosemite Valley Plan.  This alternative would not impair the wetland and aquatic resources of the park.

Vegetation

Analysis

Alternative 3 would result in short-term, adverse effects on vegetation in Yosemite Valley due to construction activities; however, most of the areas proposed for utility corridor construction have been previously disturbed by utilities, transportation facilities, or other development. Implementation of Alternative 3 would remove utility infrastructure in environmentally sensitive areas where ecological restoration is proposed.Impacts associated with Alternative 3 are summarized in table IV-12. Alternative 3 proposes the same actions as Alternative 2 in the Happy Isles, Campgrounds, Ecological Restoration, The Ahwahnee, Curry Village, Housekeeping Camp, and Yosemite Village areas, and would have the same effects described under Alternative 2. Impacts in the Camp 6/Cook’s Meadow area under Alternative 3 are described below.

Camp 6/Cook’s Meadow. Construction activities related to the proposed corridors and utility repairs in this area would result in the disturbance and localized removal of vegetation over approximately 11.3 acres, which including 0.8 acre of meadow, 2.5 acres of riparian, and 0.6 acre of oak, all highly valued resources. The vegetation or cover types that would be affected by the localized removal of vegetation include Carex senta wet meadow border, Carex vesicaria wet meadow, grass-sedge meadow, grass meadow, dense black cottonwood-willow riparian forest, oxbow and cutoff channels, mixed riparian-conifer corridor forest, impacted mixed riparian-conifer corridor forest, California black oak woodland, open ponderosa pine-California black oak woodland, developed open ponderosa pine-California black oak woodland, ponderosa pine forest, dense mixed coniferous forest, white fir-Douglas fir forest, river, developed open area-sparse vegetation, and bare.  Impacts from utility removals and abandonment in this area would be the same as discussed under Alternative 2.

Vegetation Community Types Potentially Affected by Alternative 3

 

^{a   Includes repairs to existing wastewater lines as described in Alternative 1, as well as construction of proposed consolidated utility corridors.}

Some of the areas that would be affected are within existing roadway or utility corridors that have been previously disturbed and developed. Effects would be related to heavy equipment and construction activities and could include soil disturbance and compaction, dust generation, vegetation removal, root damage, erosion, introduction and spread of non-native species, and spread of annosus root disease. The addition of pollutants (i.e., fuels or lubricants) related to construction activities could degrade the quality of native vegetation. Construction-related activities planned in this area would have short-term and potentially long-term, minor to moderate, adverse effects to vegetation due to the limited localized loss of mature trees. Localized, long-term, minor loss of vegetation due to routine clearance of vegetation at utility access manholes may also occur as a result of Alternative 3.

Removal and abandonment of utilities within the Camp 6/Cook's Meadow area would occur over approximately 8.7 acres, which include 1.6 acres of meadow, 2.2 acres of riparian, and 0.5 acre of oak, all highly valued resources. Construction and removal activities planned in this area would have short-term and potentially long-term, minor adverse effects to vegetation depending on the type of vegetation (e.g., tree, shrub, or herbaceous) and number, size, and species of trees removed.

The application of mitigation measures described in Chapter II, particularly those designed to address revegetation, minimization of disturbance areas, non-native species, and annosus root disease, would reduce these local, short-term and long-term, adverse construction-related impacts to vegetation to a minor intensity. Removal and abandonment actions in the Camp 6/Cook's Meadow area would have local, long-term, minor to moderate, beneficial effects on meadow and riparian areas through restoration of more natural subsurface water flows through the area.

Summary of Alternative 3 Impacts

Under Alternative 3, construction of integrated utility corridors and existing utility repairs are expected to have localized, short-term and potentially long-term, adverse, construction-related impacts to approximately 118.2 acres of vegetation, which include 6.3 acres of meadow, 12.3 acres of riparian, and 13.6 acres of oak, all highly valued resources. Removal and abandonment activities are expected to have localized, short-term and potentially long-term, adverse, construction-related impacts to approximately 99.5 acres of vegetation, which include 16.4 acres of meadow, 10.4 acres of riparian, and 5.2 acres of oak, all highly valued resources. The potential for long-term, adverse effects to vegetation depend on the type of vegetation (e.g., tree, shrub, or herbaceous) and number, size, and species of trees removed. The areas that would be affected are within existing corridors that have previously been disturbed and developed. Vegetation impacts over the project area are expected to be localized, short-term and potentially long-term, minor to moderate, and adverse.

Construction impacts would be mitigated through the application of mitigation measures described in Chapter II, which call for minimizing the area disturbed, revegetation, preventing the spread of invasive and non-native species, and preventing the spread of annosus root disease. Consolidation of utility infrastructure in major developed corridors, removal of utilities from environmentally sensitive areas, and restoration of more natural subsurface hydrological processes in these areas are expected to have local, long-term, minor to moderate, beneficial effects on meadow and riparian resources.

Cumulative Impacts

Cumulative impacts to vegetation resources based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley were discussed under Alternative 2. The cumulative projects evaluated would result in a local, long-term, minor, beneficial effect on vegetation within Yosemite Valley due to ecological restoration efforts. Alternative 3 would enhance the cumulative benefits from ecological restoration activities by removing utility infrastructure from the riverbanks and wet meadow areas identified for ecological restoration.

Impairment

Alternative 3 would result in local, short-term, minor to moderate, adverse effects on vegetation resources, but provide for local, long-term, moderate, beneficial effects on vegetation resources related directly to the removal of utilities from highly sensitive areas andrestoration of more natural subsurface hydrologic processes in these areas. Alternative 3 would also facilitate ecological restoration activities proposed in the Yosemite Valley Plan. This alternative would not impair the vegetation resources of the park.

Wildlife

Analysis

Construction activities associated with Alternative 3 could disturb wildlife; however, most of the areas proposed for utility corridor construction have been previously disturbed by utilities, transportation facilities, or other development. Implementation of Alternative 3 would remove utility infrastructure in areas where ecological restoration is proposed. Alternative 3 proposes the same actions as Alternative 2 in the Happy Isles, Campgrounds, Ecological Restoration, The Ahwahnee, Curry Village, Housekeeping Camp, and Yosemite Village areas, and would have the same effects described under Alternative 2. Impacts that would occur under Alternative 3 in the Camp 6/Cook’s Meadow area are described below.

Camp 6/Cook’s Meadow. Localized, minor, short-term, adverse effects on native fish and wildlife could occur during construction and removal/abandonment activities. Construction activities in the Camp 6/Cook's Meadow area could potentially affect up to 11.3 acres, which include 0.8 acre of meadow, 2.5 acres of riparian, and 0.92 acre of wetland and aquatic habitats. The wildlife habitat types that would be affected include wet meadow, montane riparian, black oak woodland, montane hardwood conifer, ponderosa pine, sierra mixed conifer, riverine, and urban. Effects would be related to heavy equipment use and human intrusion and could include noise, dust, soil disturbance and compaction, vegetation removal, trench excavation, sedimentation, elevated turbidity, and decreased oxygen levels in aquatic habitats. These actions could result in direct losses of nests, burrows, wildlife, and reproductive habitat for aquatic organisms and indirect effects through the disturbance of nesting birds or roosting bats. The addition of pollutants (i.e., fuels or lubricants) related to equipment operations in these areas could degrade the quality of the environment and the wildlife habitat it provides. Some trees and shrubs that could provide perches and nest sites would be removed to accommodate construction activities. Construction-related activities planned in this area would have short-term and potentially long-term, minor to moderate, adverse effects to vegetation due to the limited localized loss of mature trees. Localized, long-term, minor, adverse effects to wildlife due to routine clearance of vegetation at utility access manholes may also occur.

Removal and abandonment of utilities within the Camp 6/Cook's Meadow area would occur over approximately 8.7 acres, which include 1.6 acres of meadow, 2.2 acres of riparian, and 0.44 acre of wetland and aquatic habitats.   Removal and abandonment activities would have local, short-term, minor to moderate, adverse impacts on fish and wildlife.  However, these activities are also expected to enhance subsurface hydrologic processes in riparian, meadow, and other wetland and aquatic habitats, resulting in local, long-term, negligible to minor, beneficial effects.The application of mitigation measures described in Chapter II, particularly minimization of disturbance areas, scheduling construction to avoid nesting and bat hibernation periods (e.g., birds breed from March to August and bats breed from August to October), instituting controls to prevent impacts to wildlife from excavations, and spill prevention would reduce the potential adverse impacts to native fish and wildlife to a minor intensity. Additional mitigation is described under the wetland and vegetation resource areas as it relates to wildlife habitat avoidance, the minimization of impacts to wildlife habitat, and revegetation of disturbed portions of the project area.

Summary of Alternative 3 Impacts

Under Alternative 3, construction of integrated utility corridors and existing utility repairs are expected to have localized, short-term, adverse, construction-related impacts to approximately 118 acres, which include 6.3 acres of meadow, 12.3 acres of riparian, and 3.6 acres of wetland and aquatic habitats, all highly valued resources. Removal and abandonment activities are expected to have localized, short-term, adverse, construction-related impacts to approximately 99 acres, which include 16.4 acres of meadow, 10.4 acres of riparian, and 5.1 acres of wetland and aquatic habitats, all highly valued resources. The enhancement of subsurface hydrologic processes in meadows, riparian, and other wetland habitats resulting from utility removal could result in local, long-term, minor to negligible, beneficial impacts. The areas that would be affected are primarily within existing corridors that have previously been disturbed and developed.  The combined impact to wildlife resources over the entire project area may result in short and long-term impacts of minor to moderate intensity.

Construction impacts would be mitigated through the application of mitigation measures described in Chapter II. Specifically, these would include minimizing disturbance areas, scheduling construction activities to avoid nesting and bat hibernation periods, instituting controls to prevent impacts to wildlife from excavations, and implementing spill prevention measures. With the application of the mitigation measures, the effects are expected to be local, short and long-term, and minor. The size, continuity, and integrity of wildlife habitats as well as the abundance, diversity, and distribution of wildlife species would not be permanently impacted by construction activities associated with Alternative 3.

Cumulative Impacts

Cumulative impacts to wildlife based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley were discussed under Alternative 2. The cumulative projects evaluated would result in a local, long-term, minor to moderate, beneficial effect on wildlife within Yosemite Valley due to ecological restoration efforts. Alternative 3 would enhance the cumulative benefits from ecological restoration activities by removing utility infrastructure from the riverbed, riverbanks, and wet meadow areas identified for ecological restoration.

Impairment

Alternative 3 would result in local, short-term, minor, adverse effects on wildlife, but provide for local, long-term, minor to moderate, beneficial effects on wildlife habitat related directly to the removal of utilities from highly sensitive areas and restoration of more natural subsurface water flow patterns in highly valued habitats.  Alternative 3 would also facilitate the ecological restoration activities proposed in the Yosemite Valley Plan. This alternative would not impair the wildlife resources of the park.

Special-Status Species

Analysis

Special-status species known or likely to occur in the immediate vicinity of Alternative 3 actions include Wawona riffle beetle, Mariposa sideband snail, Sierra pygmy grasshopper, western pond turtle, 10 species of birds, 10 species of bats, and 14 species of plants. The following subsections discuss impacts of Alternative 3 on these species and their habitat. Implementation of Alternative 3 would remove utility infrastructure in areas where ecological restoration is proposed.

Impacts associated with Alternative 3 are described below.

Wawona Riffle Beetle. Construction activities and removal and abandonment activities in the vicinity of the Merced River may have localized, short-term, minor to moderate, adverse effects on the Wawona riffle beetle. Effects would be related to heavy equipment and human intrusion, and could include vegetation removal, decreased oxygen levels, the addition of silt, resuspension of sediment, or the introduction of pollutants (i.e., fuels or lubricants). These actions could result in direct losses of individuals or habitat for Wawona riffle beetle downstream of river crossings.

Alternative 3 would result in a local, long-term, minor to moderate beneficial impact to Wawona riffle beetle habitat by enhancing river hydrology, water quality, and floodplains due to the reduction in utility river crossings and the removal of utility infrastructure from floodplain areas designated for ecological restoration.

The application of mitigation measures, as described in Chapter II, would reduce the potential adverse impacts to Wawona riffle beetle to a minor intensity. Specifically, these measures would involve minimizing the area disturbed and implementing Best Management Practices during construction to reduce the potential for water quality impacts associated with soil erosion and construction equipment fuel releases. Directional drilling, if found to be technically and economically feasible, will be used to construct the proposed Merced River crossing near Sentinel Bridge, to reduce impacts to water quality and aquatic habitat.

Mariposa Sideband Snail. Construction activities and removal and abandonment activities within rockslide habitat may have localized, short-term, minor to moderate, adverse effects on the Mariposa sideband snail. Effects would be related to heavy equipment and human intrusion and could include vegetation removal, direct disturbance of rockslide habitat, or the introduction of pollutants (i.e., fuels or lubricants). These actions could result in direct losses of individuals or habitat for the Mariposa sideband snail in rockslide areas.

The application of mitigation measures described in Chapter II, specifically minimizing the area disturbed, installing fencing and signs to protect sensitive habitats, and implementing spill prevention, would reduce the potential adverse impacts to the Mariposa sideband snail to a minor intensity.

Sierra Pygmy Grasshopper. Construction activities and removal and abandonment activities within riparian habitats may have localized, short-term, minor to moderate, adverse effects on the Sierra pygmy grasshopper. Effects would be related to heavy equipment and human intrusion and could include vegetation removal or the introduction of pollutants (i.e., fuels or lubricants). These actions could result in direct losses of individuals or habitat for the Sierra pygmy grasshopper.

Utility removals associated with Alternative 3 would result in local, long-term, minor to moderate, beneficial impacts to Sierra pygmy grasshopper habitat by allowing more natural processes to resume within riparian areas.

The application of mitigation measures described in Chapter II, specifically, minimizing the area disturbed, timing construction in riparian habitats outside the Sierra pygmy grasshopper’s active period (e.g., schedule construction for the fall or winter), and implementing pollution prevention measures, would reduce the potential adverse impacts to the Sierra pygmy grasshopper to a minor intensity.

Western Pond Turtle. Construction activities and removal and abandonment activities in the vicinity of aquatic habitats may have localized, short-term, minor to moderate, adverse effects to the western pond turtle. Effects would be related to heavy equipment and human intrusion and could include vegetation removal, decreased oxygen levels, the addition of silt, resuspension of sediment, or the introduction of pollutants (i.e., fuels or lubricants). These actions could result in direct losses of individuals or habitat for the western pond turtle within aquatic habitats.

Utility removals associated with Alternative 3 would result in local, long-term, minor to moderate beneficial impacts to western pond turtle' habitat by allowing more natural processes to resume within wetland and aquatic habitats.

The application of mitigation measures described in Chapter II would reduce the potential adverse impacts to western pond turtle to a minor intensity. Specifically, these measures would involve minimizing the area disturbed, and implementing Best Management Practices during construction, and revegetation.

Special-Status Species of Birds. Construction activities and removal and abandonment activities may have localized, short-term, minor to moderate, adverse effects on special-status birds in the immediate vicinity of these activities. Effects would be related to heavy equipment and human intrusion and could include disruption of breeding activities or the possible direct destruction or removal of nesting habitat or sites (e.g., snags and trees). Localized, long-term, minor, adverse effects to special-status bird species and their habitat may occur as a result of routine clearance of vegetation at utility access manholes.

Utility removals associated with Alternative 3 would result in local, long-term, minor to moderate, beneficial impacts to special-status bird species habitat by allowing more natural processes to resume within wetland and riparian areas.

The application of mitigation measures described in Chapter II, specifically, Best Management Practices, limiting construction activities to outside the breeding season for special-status bird species (e.g., birds breed from March through August), and conducting pre-construction surveys in appropriate habitats if construction activities during the breeding season cannot be avoided, would reduce the potential adverse impacts to special-status bird species to a minor intensity.

Special-Status Species of Bats. Construction activities and removal and abandonment activities may have localized, short-term, minor to moderate, adverse effects to special-status bat species in the immediate vicinity of these activities. Localized, long-term, minor, adverse effects to special-status bat species and their habitat may occur as a result of routine clearance of vegetation at utility access manholes. Effects would be related to heavy equipment and human intrusion and could include disruption of breeding activities or the possible direct destruction or removal of bat roosts (e.g., snags and trees).

Utility removals associated with Alternative 3 would result in local, long-term, minor to moderate, beneficial impacts to special-status bat species habitat by allowing more natural processes to resume within wetland and riparian areas.

The application of mitigation measures described in Chapter II, specifically, conducting preconstruction surveys in appropriate habitats if construction activities during hibernation and nursing periods cannot be avoided, minimizing removal of large oak trees and large snags, and scheduling disruptive activities of construction in roosting habitat to occur when bats are neither hibernating nor have young (e.g., bats hibernate from September 1 to February 15 and bat young are nursing and unable to fly from May to mid August), would reduce the potential adverse impacts to special-status bat species to a minor intensity.

Special-Status Species of Plants. Construction activities and removal and abandonment activities may have localized, short-term, minor to moderate, adverse effects on special-status plant species in the immediate vicinity of these activities. Localized, long-term, minor, adverse effects to special-status plant species may occur as a result of routine clearance of vegetation at utility access manholes. Effects would be related to the use of heavy equipment during excavation and repair activities and could include soil disturbance and compaction, dust generation, vegetation removal, root damage, erosion, introduction and spread of non-native species, or the introduction of pollutants (i.e., fuels or lubricants).

Utility removals associated with Alternative 3 would result in local, long-term, minor to moderate, beneficial impacts to special-status plant species habitat by allowing more natural processes to resume within wetland and riparian areas.

The application of mitigation measures described in Chapter II, particularly performing rare plant surveys prior to construction in appropriate habitats and at appropriate times (e.g., during plant species flowering periods), avoiding special-status species of plants to the extent possible, minimization of disturbance areas, and implementing a noxious weed abatement program, would reduce the potential adverse impacts to special-status plant species to a minor intensity.

Summary of Alternative 3 Impacts

Activities associated with Alternative 3 would result in local, minor to moderate, , short and long-term, adverse impacts to special-status species. Implementation of mitigation measures described above and in Chapter 2 would reduce these impacts to a minor level.  No crtical habitat for special-status species would be affected.

Cumulative Impacts

Cumulative impacts to special-status species based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley were discussed under Alternative 2. The cumulative projects evaluated would result in a local, long-term, moderate, beneficial cumulative effect on special-status species within Yosemite Valley. Alternative 3 would enhance the cumulative benefits from ecological restoration activities by removing utility infrastructure from the riverbed, riverbanks, and wet meadow areas identified for ecological restoration.

Impairment

Alternative 3 would result in local, short and long-term,  minor, adverse impacts on special-status species.  This alternative would also facilitate implementation of ecological restoration activities identified in the Yosemite Valley Plan. Therefore, Alternative 3 would not impair special-status species resources.

Air Quality

Analysis

Alternative 3 would result in air quality impacts related to construction equipment emissions and operation of utility infrastructure as discussed under Alternative 2.

Summary of Alternative 2 Impacts

Alternative 3 would result in local, short-term, minor, adverse impacts to air quality and regional, long-term, negligible adverse impacts for operations of utility systems in Yosemite Valley.

Cumulative Impacts

The cumulative effects on air quality under Alternative 3 would be the same as those discussed under Alternative 2. The local, short-term, minor, adverse effects of construction and the regional, long-term, negligible, adverse effects of operations would somewhat reduce the long-term, beneficial impacts from cumulative projects in the Valley, but the overall effect of this alternative and the cumulative projects would still be beneficial.

Impairment

Implementation of Alternative 3 is expected to result in local, short-term, minor, adverse impacts to air quality from construction activities and regional, long-term, negligible adverse air quality effects from operations. These short-term, minor and long-term, negligible impacts are not expected to impair park resources for future generations.

Noise

Analysis

Alternative 3 would involve construction activities similar to those discussed under Alternative 2. Construction-related noise impacts in the Happy Isles, Campgrounds, Ecological Restoration, The Ahwahnee, Curry Village, Housekeeping Camp, and Yosemite Village areas would be the same as discussed under Alternative 2. Alternative 3 impacts in the Camp 6/Cook’s Meadow area are described below.

Camp 6/Cook’s Meadow. Construction of the Sentinel Drive River Crossing Utility Corridor across the Merced River east of Sentinel Bridge would likely result in adverse noise impacts to park visitors, particularly those accessing the Sentinel Bridge area. These construction impacts are expected to be local, short-term, moderate to major, adverse effects.

Summary of Alternative 3 Impacts

Construction of utility corridors and associated infrastructure under Alternative 3 would result in local, short-term, moderate to major, adverse impacts to park visitors and residents. Alternative 3 is not expected to impact long-term ambient noise levels in Yosemite Valley.

Cumulative Impacts

Cumulative effects to the ambient noise environment would be similar to those discussed under Alternative 2. Alternative 3 would contribute in the short-term to the cumulative local, long-term, minor, adverse effects on ambient noise in Yosemite Valley.

Impairment

Alternative 3 would result in local, short-term, moderate to major, adverse effects on noise in Yosemite Valley during construction activities. Alternative 3 would not have any long-term, adverse noise effects and would not impair park resources for future generations.

Cultural Resources

Archeological Resources

Analysis

The only difference between the activities proposed for Alternatives 2 and 3 that could have an effect on cultural resources is the river crossing just east of Sentinel Bridge (Alternative 3) instead of the river crossing just west of Housekeeping Camp (Alternative 2). Therefore, potential impacts discussed under Alternative 2 also apply to Alternative 3, plus any impacts specific to areas affected by the Sentinel Bridge area river crossing. Potential indirect impacts on cultural resources from changes in traffic patterns as described for Alternative 1 apply to Alternative 3 as well.

The only recorded archeological sites that may be impacted by Alternative 3 actions that are not impacted under Alternative 2 occur in the Camp 6/Cook’s Meadow area.

Camp 6/Cook’s Meadow. Intact sediments at up to three archeological sites in the Camp 6/Cook’s Meadow area may be disturbed by grading, trenching, and earthmoving activities necessary to install new or redevelop existing utility corridors under Alternative 3 (in addition to those discussed under Alternative 2 above). These sites consist of prehistoric and historic American Indian habitation sites ranging in estimated data potential from low to moderate.   One site has not been evaluated to determine its nature, extent, integrity and specific data potential, so the boundaries are based only on surface observations and its potential eligibility for inclusion in the National Register of Historic Places is unknown. This site will be evaluated through test excavations and where utility line construction would result in loss of important archeological information, data recovery to retrieve important information, carried out in accordance with the 1999 Programmatic Agreement, would reduce the intensity of permanent adverse impacts from moderate to minor or negligible.

The second site has had limited subsurface work revealing that at least part of the site occurs in the proposed impact area near Sentinel Bridge. The site boundaries would be verified through subsurface testing and the contents examined for their data potential and contribution to the site’s National Register of Historic Places eligibility. Data recovery, if determined to be required based on the testing results, would be conducted as described above.

The third site, located on the north side of the Merced River at the Sentinel Bridge, could be affected by the proposed river crossing and the proposed pipe bursting and abandonment of the existing wastewater utility line north of the site. This site has been tested and data recovery excavations conducted as well. However, the report of this work has not been finalized and thus the mitigation of effect to the site has not been completed under the terms of the 1999 Programmatic Agreement. A review of the draft report does indicate that the work done at the site was adequate to document the important information the site offers and to conduct additional testing or data recovery excavation would be redundant. Impacts from construction activities at this location would be mitigated through archeological monitoring and any important artifacts or features collected, as appropriate, would be added to the collection that resulted from the previous archeological investigations.

Summary of Alternative 3 Impacts

Alternative 3 has the potential to affect 25 known sites.  Of these sites, seven have low data potential, eight have moderate data potential, and ten have high data potential.  Impacts to three sites can be mitigated through data recovery.  Tesing would be required at 17 sites to determine if the resulting impacts would be adverse. The effects analyzed under the National Historic Preservation Act and impacts analyzed under NEPA would be the same as Alternative 2 with implementation of mitigation methods as described under Alternatives 1 and 2 earlier in this chapter.

Cumulative Impacts

Cumulative impacts to archeological resources based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley would be the same as discussed under Alternative 1 earlier in this chapter. Overall, the cumulative projects are expected to have a local, long-term, minor, adverse effect to archeological sites with implementation of appropriate mitigation measures in accordance with the Programmatic Agreement. Alternative 3 would contribute to this minor adverse effect.

Impairment

Although high value cultural resources are located within the Area of Potential Effect, the effect of this alternative on archeological resources would be primarily localized, and the effect would be mitigated through data recovery. Alternative 3 would not change the treatment and management of archeological resources and would not impair the park’s archeological resources.

Traditional Cultural Resources

Analysis

The actions proposed under Alternative 3 have the potential to impact the same traditional cultural resources discussed under Alternative 2, as well as the historic American Indian habitation site of Hawkhawkooetah (Bibby 1994) south of the Sentinel Bridge. National Historic Preservation Act effects and the level of NEPA impacts would be the same as discussed under Alternative 2. Construction activities associated with implementation of Alternative 3 would be expected to have local, short-term, minor, adverse effects on traditional cultural resources. The park has initiated consultation with culturally associated American Indian tribes regarding potential impacts to the cultural values associated with each property and appropriate ways to mitigate potential impacts. The mitigation measures developed through consultation are discussed in Chapter II.

Summary of Alternative 3 Impacts

Construction activities associated with Alternative 3 would likely result in local, short-term, minor to moderate, adverse impacts to traditional cultural resources, including eight traditional gathering areas and seven historic Native American habitation sites.. Through consultation with culturally associated American Indian tribes regarding the potential adverse impacts to traditional cultural resources and appropriate mitigation measures, mitigation measures have been incorporated into the project to mitigate the potential adverse effects.

Cumulative Impacts

Cumulative impacts to traditional cultural resources based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley would be the same under Alternative 3 as discussed under Alternative 2. Overall, the cumulative projects are expected to have a local, long-term, minor, adverse effect to traditional cultural resources. Alternative 3 would contribute to this minor, adverse effect. Cumulative impacts to traditional cultural resources are being addressed by the park through regular  consultation with culturally associated American Indian tribes.

Impairment

Alternative 3 is expected to result in minor, adverse effects to traditional cultural resources after mitigation. This alternative is not expected to impair the park’s resources for future generations.

Cultural Landscapes, including Historic Sites and Structures

Analysis

Potential impacts identified under Alternative 2 would be the same under Alternative 3 as well. Sentinel Bridge, located adjacent to the proposed utility corridor river crossing for Alternative 3, is not one of the historic bridges listed in the Yosemite Valley Bridges National Register of Historic Places Nomination Form. The potential impacts to elements of the Valley Loop Trail identified for Alternative 2 also would apply to Alternative 3, which would include an additional segment of the trail between Housekeeping Camp and nearly to Sentinel Bridge. The historic elements of the trail should be marked in advance of construction activities at these locations, and equipment operators should be made aware of these elements’ presence and importance. The impacts to The Ahwahnee associated with the generator housing structure would also apply to Alternative 3.

Direct adverse impacts on the cultural landscape of the actions proposed for Alternative 3 are expected to be local, short-term, and minor and are adequately addressed by the construction mitigation measures provided in Chapter II.

Summary of Alternative 3 Impacts

Construction activities associated with Alternative 3 would be the same as described for Alternative 2, but could result in direct or indirect effects to a different section of the Valley Loop Trail. These adverse effects are expected to be local, short-term, and minor and should be appropriately mitigated through mitigation measures discussed in Chapter II.

Cumulative Impacts

Cumulative impacts to cultural landscape resources, including historic sites and structures, based on analysis of past, present, and reasonably foreseeable future actions in Yosemite Valley would be the same under Alternative 3 as discussed under Alternative 2. Overall, the cumulative projects are expected to have local, long-term, negligible to minor, cumulative adverse effects. Alternative 3 would contribute to this minor, adverse effect.

Impairment

Alternative 3 is expected to have minor, adverse effects and would not impair park cultural landscape resources for future generations.

Section 106 Summary for Alternative 3

Under regulations of the Advisory Council on Historic Preservation (36 CFR 800.9) addressing the criteria of effect and adverse effect, the National Park Service finds that actions under this alternative would have the potential to adversely affect significant historic properties.  Some archeological sites may be at risk of disturbance during construction of proposed utility corridors and removal or abandonment of utilities in areas proposed for ecological restoration.  If archeological sites could not be avoided, monitoring and data recovery carried out in accordance with the 1999 Programmatic Agreement would retrieve important information from the disturbed resources, thereby avoiding adverse impacts. Proposed activities in the Tenaya Creek Campground Utility Corridor, however, have the potential to affect a large site that includes an area where human remains have been discovered.  Therefore, activities in this area could have an adverse effect.  To mitigate this adverse effect, a testing plan and discovery plan would be implemented in consultation with the State Historic Preservation Officer and the culturally associated American Indian groups. Construction of the Tenaya Creek Campground Utility Corridor will not proceed until the potential effects of activities in this area are appropriately mitigated.  Traditional cultural resources may also be disturbed during construction activities associated with utility corridor construction and utility removal and abandonment.  The park has developed mitigation measures through consultation with culturally associated American Indians to address adverse effects on these resources.  Activities proposed under Alternative 3 could also adversely affect cultural landscape resources, including historic sites, by construction activities near sites or the addition of a new facility.  Above ground structures will be minimized by placing transformers, pumps and piping underground.  New facilities will be sited and designed to screen the structures from important vantage points. 

In accordance with National Park Service policies and procedures, the park would continue to protect cultural resources to the greatest extent possible.  Disturbance of significant cultural resources would be avoided wherever possible, but in instances where avoidance or preservation could not be achieved, appropriate mitigation would be carried out under provisions of the 1999 Programmatic Agreement.

Social Resources

Scenic Resources

Analysis

Alternative 3 would result in the same short-term construction-related impacts to scenic resources as described under Alternative 2. Alternative 3 would not impact landscape character, access to important viewpoints, or visibility of viewpoints in the long-term. Construction would have localized, short-term, minor to moderate, adverse impacts on scenic Valley views from various vantage points. Although views of scenic features would not be obstructed, there is a potential for the visual intrusion of construction activities into the view. Impacts to scenic resources in the Happy Isles, Campgrounds, Ecological Restoration, The Ahwahnee, Curry Village, Housekeeping Camp, and Yosemite Village areas would be the same as discussed under Alternative 2. Impacts in the Camp 6/Cook’s Meadow area that would differ from Alternative 2 are described below.

Camp 6/Cook’s Meadow. Alternative 3 proposes construction of a Merced River utility crossing just east of Sentinel Bridge. Construction in this area would be clearly visible from Sentinel Bridge and could have adverse effects on views of some scenic features through intrusion of construction activity into the view. This would result in short-term, local, moderate, adverse impacts to scenic resources.

Summary of Alternative 3 Impacts

Alternative 3 would result in local, short-term, minor to moderate, adverse impacts and local, long-term, minor, adverse impacts to highly valued scenic resources in Yosemite Valley.

Cumulative Impacts

Cumulative impacts to scenic resources would be the same as discussed under Alternative 2. Cumulative projects within the Valley would result in a local, long-term, major, beneficial cumulative impact on scenic resources in Yosemite Valley because of the overall emphasis on restoring disturbed or developed land to natural conditions within A category scenic areas and improving the health of ecosystems within Yosemite Valley. Alternative 3 would not diminish the local, long-term, major, beneficial impact on scenic resources in Yosemite Valley from the cumulative projects.

Impairment

Alternative 3 would result in short-term, moderate, adverse impacts to scenic resources due to intrusion of construction activity into Valley views and views of scenic features. This alternative is not expected to have any long-term, adverse effect on scenic resources and would not impair park resources for future generations.

Visitor Experience and Recreational Resources

Analysis

Impacts to visitor experience and recreational resources under Alternative 3 would be similar to those discussed under Alternative 2. Construction would have a local, short-term, minor to moderate, adverse effect on visitor experience and recreation activities near construction sites.

Alternative 3 impacts in the Happy Isles, Campgrounds, Ecological Restoration, The Ahwahnee, Curry Village, Housekeeping Camp, and Yosemite Village areas would be the same as those discussed under Alternative 2. Impacts in the Camp 6/Cook’s Meadow area that would occur under Alternative 3 are described below.

Camp 6/Cook’s Meadow. Construction activities in this area could result in short-term access restrictions near Sentinel Bridge as the Sentinel Drive River Crossing Utility Corridor is constructed. Noise and other construction impacts would also result in short-term, adverse effects on visitor experiences in this area during the construction period. Overall, construction in the Camp 6/Cook’s Meadow area is expected to have a local, short-term, moderate, adverse effect on visitor experience and recreation.

Summary of Alternative 3 Impacts

Alternative 3 would result in local, short-term, minor to moderate, adverse impacts on the quality of visitor experience and recreation near construction sites. Alternative 3 would not result in any long-term, adverse effects on recreational resources or visitor experiences.

Cumulative Impacts

Cumulative impacts on recreation would be the same as discussed under Alternative 2. The cumulative projects would have a local, long-term, moderate, beneficial effect on recreation due to expanded recreational opportunities in Yosemite Valley and improved transit service distributing visitors to more park destinations.

Alternative 3 would reduce these beneficial effects in the short-term but should not have any long-term effect. Therefore, the cumulative projects with Alternative 3 are still expected to have a local, long-term, moderate, beneficial effect on recreation.

Impairment

Alternative 3 would result in local, short-term, minor to moderate, adverse impacts on recreation activities near construction areas. Alternative 3 is not expected to impact the diversity or quality of recreational opportunities in Yosemite Valley for the long term. Therefore, Alternative 3 would not impair the park’s recreational resources for future generations.

Park Operations and Facilities

Transportation

Analysis. Alternative 3 would have short-term, local, minor to moderate, adverse effects on traffic volume, circulation, delays, and safety related to construction activities. This alternative is not expected to have any long-term impact on traffic volumes, circulation, delays, or safety.

Construction impacts on transportation facilities would be the same in the Happy Isles, Campgrounds, Ecological Restoration, The Ahwahnee, Curry Village, Housekeeping Camp, and Yosemite Village areas as described under Alternative 2.

Camp 6/Cook’s Meadow. Construction of Alternative 3 would require temporary road closures of Southside Drive and Sentinel Drive, which would result in local, short-term, moderate, adverse impacts to traffic circulation, delays, and safety.

Summary of Alternative 3 Impacts. Alternative 3 would result in local, short-term, minor to moderate, adverse effects on transportation volumes, circulation, delays, and safety within Yosemite Valley during construction activities. These impacts would be minimized and mitigated through development of a Visitor Communication and Protection Plan prior to start of construction.

Cumulative Impacts. Cumulative effects on transportation facilities and traffic circulation and safety from other past, present, and reasonably foreseeable future actions in Yosemite Valley would be the same as discussed under Alternative 2. Collectively, the cumulative projects are expected to have a local, long-term, major, beneficial impact on transportation. Construction impacts to traffic circulation under Alternative 3 would contribute to lowering the beneficial effects on transportation in the short term.

Conclusions. Alternative 3 would result in local, short-term, minor to moderate, adverse impacts to traffic circulation and safety. No long-term, adverse impacts on traffic circulation or safety are expected.

Impairment. The National Park Service has a management responsibility to conserve the scenery, natural and historic objects, and wildlife resources of the park. Traffic operations are not subject to the impairment standard.

Park Operations

Analysis. Alternative 3 proposes consolidation of utility infrastructure into integrated corridors similar to Alternative 2. Consolidation of utility infrastructure and the reduction of Merced River utility crossings would have a beneficial effect on park operations in the long run. The increased number of lift stations and electric transformers, however, could result in increased operations and maintenance costs. Overall, Alternative 3 would result in a local, long-term, negligible to minor, adverse effect on park operations from increased operating costs.

Summary of Alternative 3 Impacts. Alternative 3 would have local, long-term, negligible to minor, adverse impacts on park operations.

Cumulative Impacts. Cumulative effects on park operations and facilities from past, present, and reasonably foreseeable future actions in Yosemite Valley would be the same as addressed under Alternative 2. Overall, the past, present, and reasonably foreseeable future actions would have local, short- and long-term, moderate to major, adverse cumulative impacts because of the increased demand on park operations, services, and facilities. Alternative 3 would not change this cumulative effect.

Conclusions. Alternative 3 would result in local, long-term, negligible to minor, adverse impacts on park operations and facilities related to increased costs associated with additional lift stations and electric transformers. These costs may be offset somewhat by reduced maintenance costs associated with fewer river and creek utility crossings.

Impairment. The National Park Service has a management responsibility to conserve the scenery, natural and historic objects, and wildlife resources of the park. Park operations are not subject to the impairment standard.

Socioeconomics

Analysis

Alternative 3 socioeconomic impacts would be similar to those described for Alternative 2, but implementation of Alternative 3 would result in slightly higher construction expenditures due to the extra length of utility corridors associated with this alternative. Alternative 3 would result in $85.3 million of direct expenditures on materials, labor, and equipment. Typically, design and engineering costs are spent outside of the region and can account for up to 25% of the total estimated project cost. In addition, a significant portion of construction costs also may be spent outside the region. It was estimated that approximately 50% of the total $85.3 million would be spent within the three-county region of Mariposa, Madera, and Tuolumne Counties.

In addition to the expected $42.7 million in direct expenditures within the region, the construction expenditures would result in secondary and induced effects within the economy as the construction dollars are spent by businesses and households. Secondary and induced impacts for this alternative were estimated at $100.6 million of economic output in the region, including $32.4 million in earnings to households and creation of 918 jobs in the regional economy. Based on 2000 economic data presented in Chapter III, the changes in economic output and employment would represent an increase of 1.5% over existing conditions. This would not likely result in any discernible effect on the social and economic environment of the region. Therefore, construction expenditures related to this alternative would have a short-term, negligible, beneficial impact on the regional economy.

Summary of Alternative 3 Impacts

Alternative 3 would result in regional, short-term, negligible, beneficial effects on the economy due to direct expenditures and indirect benefits associated with increased construction expenditures.

Cumulative Impacts

The effect of cumulative projects on the region’s economy would be the same as discussed under Alternative 2. Since Alternative 3 would result in additional short-term, regional, beneficial effects on the economy and would support the implementation of projects proposed under the Yosemite Valley Plan, the effect of Alternative 3 and the cumulative projects would be long-term, negligible, and beneficial for the regional economy.

Impairment

Implementation of Alternative 3 would result in regional, short-term, negligible, beneficial effects on the economy and would not impair park resources for future generations.