Merced Wild and Scenic River Section 7 Determination

Introduction

Purpose, Authority, and Designation

The purpose of this determination is to evaluate whether the impact of the proposed East Yosemite Valley Utilities Improvement Plan would directly and adversely affect the free-flowing condition and Outstandingly Remarkable Values for the affected segments of the Merced River.

The authority for this determination was enacted under Section 7(a) of the Wild and Scenic Rivers Act (Public Law (PL) 90-542, as amended, 16 United States Code (USC) 1271-1278). Section 7(a) states, in part:

“no department or agency of the United States shall assist by loan, grant, license or otherwise in the construction of any water resources project that would have a direct and adverse effect on the values for which such river was established, as determined by the Secretary charged with its administration.”

The Wild and Scenic Rivers Act does not prohibit development along a river corridor; however, the act does specify guidelines for the determination of appropriate actions within the bed and banks of a Wild and Scenic River.^[1] As the designated manager for the Merced River segments within the boundaries of Yosemite National Park and the El Portal Administrative Site, the National Park Service must prepare a Section 7 determination on all proposed water resources projects (includes bridges and other roadway construction/reconstruction projects^[2]) to ensure they do not directly and adversely impact the free-flowing condition or the values for which the river was designated.^[3]

Wild and Scenic River Designation

During 1987, Congress designated the Merced River a Wild and Scenic River to protect its free-flowing condition and to protect and enhance its unique values for the benefit and enjoyment of present and future generations (16 USC 1271). This designation provides special protection for the Merced River and designated tributaries under the Wild and Scenic Rivers Act.

Passage of PL 100-149 (1987) and PL 102-432 (1992) placed 122 miles of the main stem and South Fork Merced River into the Wild and Scenic River System. Rivers tributary to the Merced, besides the South Fork, and also included were the Red Peak, Merced Peak, Triple Peak, and Lyell. The National Park Service manages 81 miles of the river system (including the Merced River main stem and the South Fork within Yosemite National Park and the El Portal Administrative Site), while the remaining 41 designated river miles are managed by the U.S. Forest Service and the U.S. Bureau of Land Management.

East Yosemite valley utilities improvement plan Wild and Scenic Rivers Act Section 7 Determination

The Section 7 evaluation for the East Yosemite Valley Utilities Improvement Plan has been summarized in table 3-1. This evaluation was based on guidance provided within the Wild and Scenic Rivers Act: Section 7 Technical Report (Interagency Wild and Scenic Rivers Coordinating Council), Appendix C, Evaluation Procedure under the heading Direct and Adverse. The direct and adverse evaluation procedure is carried out for water resources projects licensed by the Federal Energy Regulatory Commission or other federally assisted water resources projects within the bed or banks of the designated river. The East Yosemite Valley Utilities Improvement Plan includes construction activities within the bed and banks of the Merced River; as well as removal of utility infrastructure from the river and adjacent areas.  The Section 7 determination process presented herein applies only to the Preferred Alternative. The Preferred Alternative as discussed in this document, is the Selected Alternative.

Outstandingly Remarkable Values

Outstandingly Remarkable Values are the river-related values that make the river segment unique and worthy of special protection. They form the basis for the river’s designation as a Wild and Scenic River. Outstandingly Remarkable Values for the Main Stem – Valley segment include:

§         Scientific – The entire river corridor constitutes a highly significant scientific resource because the river watershed is largely within designated Wilderness in Yosemite National Park. Scientific Outstandingly Remarkable Values relate to the Merced River values for research. This Outstandingly Remarkable Value applies to all the Merced River segments.

§         Scenic – The Valley segment provides magnificent views from the river and its banks of waterfalls (Nevada, Vernal, Illilouette, Yosemite, Sentinel, Ribbon, Bridalveil, and Silver Strand), rock cliffs (Half Dome, North Dome/Washington Column, Glacier Point, Yosemite Point/Lost Arrow Spire, Sentinel Rock, Three Brothers, Cathedral Rock, and El Capitan), and meadows (Stoneman, Ahwahnee, Cook’s, Sentinel, Leidig, El Capitan, and Bridalveil). There is a scenic interface of river, rock, meadow, and forest throughout the segment.

§         Recreation – This segment offers opportunities to experience a spectrum of river-related recreational activities, from nature study and sightseeing to hiking. Yosemite Valley is one of the premier outdoor recreation areas in the world.

Table 3-1

Section 7 Evaluation for East Yosemite Valley Utilities Improvement Plan

Evaluation Criteria	Project Data
Define The Proposed Activity
Project proponent	National Park Service, Yosemite National Park
Purpose and need for the project	The purpose of the East Yosemite Valley Utilities Improvement Plan is to develop integrated utility corridors located in environmentally preferable areas, and to reduce utility infrastructure located in environmentally sensitive areas. The proposed project would reduce utility infrastructure within the River Protection Overlay and within adjacent areas proposed for ecological restoration.
Geographic location of the project	The East Yosemite Valley Utilities Improvement Plan will include improvements located primarily within the eastern portion of Yosemite Valley, from the water storage facility south of Happy Isles to the Yosemite Lodge area.
Project description	The Selected Alternative includes construction of integrated utility corridors located in existing utility corridors and along existing or proposed transportation corridors; a reduction in the number of Merced River and major tributary utility crossings; a reduction in the amount of utility infrastructure located within the River Protection Overlay; and removal or abandonment of utility infrastructure located within riparian areas proposed for ecological restoration. Refer to the description of the Selected Alternative (Alternative 2) in the East Yosemite Valley Utilities Improvement Plan Environmental Assessment, Chapter II.
Duration of the proposed activities	Implementation of the East Yosemite Valley Utilities Improvement Plan would occur in phases over the next 10 years. Phase 1 would begin in the fall of 2003 and would include construction of the proposed Merced River crossing. In-channel work, bank stabilization, and revegetation would be completed within a two- to three-month period during the fall of 2003 (September through November) when the flow of the Merced River is typically lowest (less than 200 cubic feet per second). Phase 2 of the East Yosemite Valley Utilities Improvement Plan is expected to begin in January 2004 and would be coordinated with reconstruction activities proposed for the east Valley campgrounds. Later phases of the proposed project would occur as redevelopment occurs in other areas. For example, removal of river crossings and utility infrastructure in meadow areas identified for restoration would be coordinated with ecological restoration activities in these areas.
Magnitude and/or extent of the proposed activities	The East Yosemite Valley Utilities Improvement Plan proposes development of integrated utility corridors and relocation of utility infrastructure out of environmentally sensitive areas and into environmentally preferable areas. The East Yosemite Valley Utilities Improvement Plan proposes one new Merced River utility corridor crossing and alteration of two additional Merced River utility crossings. It also proposes removal of several existing Merced River crossings and major tributary crossings. Refer to the East Yosemite Valley Utilities Improvement Plan Environmental Assessment, Chapter IV, Environmental Consequences, for detailed data concerning potential impacts of the proposed action.
Mitigation	The East Yosemite Valley Utilities Improvement Plan is designed to locate utility infrastructure in environmentally preferable areas, reducing utility crossings of the Merced River and major tributaries, as well as removing or abandoning utility infrastructure in areas identified for ecological restoration in the Yosemite Valley Plan. Mitigation (e.g., Best Management Practices and resource-specific measures) is incorporated into the Selected Alternative. Refer to the East Yosemite Valley Utilities Improvement Plan Environmental Assessment, Chapter II, Alternatives, for mitigation measures incorporated into the Selected Alternative.

Evaluation Criteria	Project Data
Define The Proposed Activity
Relationship to past and future management activities	The Yosemite Valley Plan calls for utility relocation to reduce impacts to environmentally sensitive areas and to provide efficient utility service to areas identified for redevelopment. The East Yosemite Valley Utilities Improvement Plan is consistent with the Yosemite Valley Plan. The Selected Alternative is also consistent with the Wild and Scenic River guidance provided in the Merced River Plan. Implementation of the Selected Alternative and associated actions under the Yosemite Valley Plan would enhance the free flow of the river and riparian and floodplain extent, functions, and values. The Selected Alternative would have a beneficial effect on the biological and hydrologic processes of the river.
Describe Whether The Proposed Activity Will Directly Alter Within-Channel Conditions
The position of the proposed activity relative to the streambed and streambanks	The East Yosemite Valley Utilities Improvement Plan implementation activities would occur throughout the east Valley. Both construction and removal of utility infrastructure will occur within the River Protection Overlay and within the bed and banks of the Merced River as well.
Any likely resulting changes in:
Active channel location	The East Yosemite Valley Utilities Improvement Plan will eliminate several existing utility lines that are buried beneath the Merced River riverbed. Three of these utility crossings are currently exposed and affect the natural flow of the Merced River. In addition, the Selected Alternative will install one new consolidated Merced River utility crossing and replace two existing crossings. These crossings will be designed to minimize potential impacts to the river’s free flow and are not expected to adversely impact existing channel locations. The utility crossings will be placed approximately 8 feet below the riverbed, and the riverbed will be returned to the pre-existing contour.
Channel geometry (cross-sectional shape, width, depth characteristics)	The East Yosemite Valley Utilities Improvement Plan will eliminate several existing utility lines that are buried beneath the Merced River riverbed. Three of these utility crossings are currently exposed and affect the natural flow of the Merced River. In addition, the Selected Alternative will install one new Merced River utility crossing and replace two existing crossings. These crossings will be designed to minimize impacts to the river’s free flow. The utility crossings will be placed approximately 8 feet below the riverbed and the riverbed will be returned to the pre-existing contour. Therefore, once constructed, the Selected Alternative is not expected to create conditions that would alter existing channel geometry.
Channel slope (rate or nature of vertical drop)	As discussed above, the Selected Alternative will eliminate several existing utility lines that are buried beneath the Merced River riverbed, install one new Merced River utility crossing, and replace two other existing crossings. These new crossings will be designed to minimize impacts to the river’s free flow. The utility crossings will be placed approximately 8 feet below the riverbed, and the riverbed will be returned to the pre-existing contour. Therefore, once constructed, the Selected Alternative is not expected to create conditions that would have an adverse impact to or impede the river’s natural channel slope.
Channel form (straight, meandering, or braided)	The utility crossings will be placed approximately 8 feet below the riverbed. When construction activities have been completed, the riverbed will be returned to the pre-existing contour. Therefore, the Selected Alternative is not expected to alter the rivers existing channel form.
Relevant water quality parameters (turbidity, temperature, nutrient availability)	During construction at periods of low water, turbidity impacts to the river would likely be small and would be mitigated through application of Best Management Practices. Refer to the East Yosemite Valley Utilities Improvement Plan Environmental Assessment, Chapter II, Alternatives, for mitigation measures incorporated into the Selected Alternative. Once construction is completed, the Selected Alternative would have no effect on river water quality.

Evaluation Criteria	Project Data
Describe Whether The Proposed Activity Will Directly Alter Within-Channel Conditions
Navigation of the river	River navigation as defined by the U.S. Army Corps of Engineers is not applicable to this section of the river. Only 20 miles of the Merced River, from its confluence with the San Joaquin River, is designated as navigable by the U.S. Army Corps of Engineers.
Describe Whether The Proposed Activity Will Directly Alter Riparian And/Or Floodplain Conditions
The position of the proposed activity relative to the riparian area and floodplain	The East Yosemite Valley Utilities Improvement Plan proposes actions throughout the east Valley. The overall affect of the Selected Alternative is to reduce utility infrastructure within the riparian area and floodplain. Utility infrastructure may be removed or abandoned in riparian areas identified for ecological restoration.
Any likely resulting changes in:
Vegetation composition, age structure, quantity, or vigor	Construction activities will result in short-term loss of vegetation in construction areas. The reduction of utility infrastructure in areas identified for ecological restoration should result in long-term beneficial affects on vegetation. Refer to the East Yosemite Valley Utilities Improvement Plan Environmental Assessment, Chapter IV, Environmental Consequences, for a detailed discussion of impacts to vegetation.
Relevant soil properties such as compaction or percent bare ground	Construction activities will result in minor short-term adverse impacts to soils in construction areas where riparian or floodplain conditions exist. The reduction of utility infrastructure in areas identified for ecological restoration should result in long-term beneficial affects on soils. Refer to the East Yosemite Valley Utilities Improvement Plan Environmental Assessment, Chapter IV, Environmental Consequences, for a detailed discussion of impacts to soils.
Relevant floodplain properties such as width, roughness, bank stability, or susceptibility to erosion	Implementation of the East Yosemite Valley Utilities Improvement Plan will result in a reduction of utility infrastructure within the floodplain. The reduction in utility crossings of the river would be expected to have long-term beneficial effects on bank stability and erosion in the areas where utility crossings are removed. Refer to the East Yosemite Valley Utilities Improvement Plan Environmental Assessment, Chapter IV, Environmental Consequences, for a detailed discussion of impacts to floodplains.
Describe Whether The Proposed Activity Will Directly Alter Upland Conditions
The position of the proposed activity relative to the uplands	Implementation of the East Yosemite Valley Utilities Improvement Plan will include construction of integrated utility corridors in upland areas. Utility corridors have been located, where possible, in previously disturbed areas such as utility and transportation corridors. Refer to the East Yosemite Valley Utilities Improvement Plan Environmental Assessment, Chapter IV, Environmental Consequences, for a detailed discussion of impacts to uplands.
Any likely resulting changes in:
Vegetation composition, age structure, quantity, or vigor	Construction activities will result in short term impacts to upland vegetation. Corridors have been located in previously disturbed areas, where possible. The Phase 1 utility corridor construction could result in minor impacts to upland vegetation in the Camp 6 area. Refer to the East Yosemite Valley Utilities Improvement Plan Environmental Assessment, Chapter IV, Environmental Consequences for a detailed discussion of impacts to vegetation.
Relevant soil properties such as compaction or percent bare ground	Construction activities will result in short-term impacts to soils in construction areas. The reduction of utility infrastructure in areas identified for ecological restoration should result in long term beneficial affects on soils. Refer to the East Yosemite Valley Utilities Improvement Plan Environmental Assessment, Chapter IV, Environmental Consequences, for a detailed discussion of impacts to soils.

Evaluation Criteria	Project Data
Describe Whether The Proposed Activity Will Directly Alter Upland Conditions
Relevant hydrologic properties such as drainage patterns or the character of surface and subsurface flows	Hydrologic properties would improve in areas designated for ecological restoration where utilities would be removed. In other areas, construction mitigation measures designed to protect hydrologic properties include salvage and reuse of soils excavated and recontouring of construction areas to pre-existing contours.
Potential changes in upland conditions that would influence archeological, cultural, or other identified significant resource values	Construction activities would be performed in accordance with stipulations in the parkwide 1999 Programmatic Agreement and the 1986 Memorandum of Agreement. The Selected Alternative would not influence archeological, cultural, or other identified significant resource values in uplands of the Merced River.
Evaluate And Describe Whether Changes In On-Site Conditions Can Or Will Alter Existing Hydrologic Or Biologic Processes
The ability of the channel to change course, re-occupy former segments, or inundate its floodplain	The project would reduce utility infrastructure within the riverbed and adjacent floodplains. The Selected Alternative would not enhance or impede the ability of the river to inundate the floodplain.
Streambank erosion potential, sediment routing and deposition, or debris loading	The project would reduce utility infrastructure within the riverbed, including utility crossings that are currently exposed. The Selected Alternative would also reduce the need for access to the riverbank and riverbed areas for utility maintenance and repairs. This would be expected to reduce the potential for streambank erosion, sediment routing and deposition or debris loading over the long-term.
The amount or timing of flow in the channel	The proposed project would not affect the amount or timing of flow in the Merced River.
Existing flow patterns	Removal of exposed utility crossings in the Merced River and major tributaries will help allow the river to return to more natural flow patterns. New construction would be placed well below existing river channel depths and would not impede existing flow patterns.
Surface and subsurface flow characteristics	The proposed project is not expected to result in significant changes to surface and subsurface flow characteristics.
Flood storage (detention storage)	The Selected Alternative is not expected to have a measurable effect on river flood storage capability.
Aggregation and or degradation of the channel	The Selected Alternative is not expected to have a measurable effect on aggregation and/or degradation of the river’s natural channel properties.
Biological processes such as:
Reproduction, vigor, growth, and/or succession of streamside vegetation	Implementation of the East Yosemite Valley Utilities Improvement Plan would reduce utility infrastructure within the riverbed and adjacent riparian areas.
Nutrient cycling	The proposed project is not expected to have a measurable effect on natural nutrient cycling processes.
Fish spawning and/or rearing success	The Selected Alternative would result in a reduction of utility infrastructure within the riverbed and adjacent areas. The project would enhance the free-flowing condition of the Merced River and the biological integrity of this segment for native fish and wildlife.
Riparian-dependent avian species needs	The reduction of utility infrastructure within riparian areas would reduce future impacts to these areas and enhance riparian habitats.

Evaluation Criteria	Project Data
Evaluate And Describe Whether Changes In On-Site Conditions Can Or Will Alter Existing Hydrologic Or Biologic Processes
Amphibian/mollusk needs	In-channel construction activities could result in short-term impacts to amphibians or mollusks at utility crossing sites. Mitigation measures (e.g., Best Management Practices, species-specific monitoring) would reduce the identified effects to a negligible intensity. Refer to the East Yosemite Valley Utilities Improvement Plan Environmental Assessment, Chapter II, Alternatives, for mitigation measures incorporated into the Selected Alternative. Over the long term, the reduction of utility infrastructure within the riverbed and adjacent areas would have a beneficial impact on habitat for species of amphibians and mollusks native to the Merced River.
Species composition (diversity)	Reduction of utility infrastructure within the riverbed and adjacent areas would enhance riparian habitat and have a beneficial effect on species composition.
Estimate The Magnitude And Spatial Extent Of Potential Off-Site Changes
Consider and document:
Changes that influence other parts of the river system	Implementation of the East Yosemite Valley Utilities Improvement Plan will occur throughout the Valley, and will result in temporary localized construction-related affects that are not expected to adversely affect the river long-term. The removal of utilities in areas slated for ecological restoration will enhance hydrologic processes in these areas that could result in a positive influence on the river system.
The range of circumstances under which off-site changes might occur (for example, as may be related to flow frequency)	Implementation of the East Yosemite Valley Utilities Improvement Plan is not expected to create circumstances under which changes in off-site would result in impairment of natural river flow frequencies or volumes.
The likelihood that predicted changes will be realized	The changes associated with a reduction of utility crossings in the Merced River and other environmentally sensitive area would be realized upon full implementation of the project.
Specify processes involved, such as water and sediment, and the movement of nutrients	Natural fluvial processes such as free flow, sediment transport, and nutrient exchange would be enhanced upon completion of the Selected Alternative.
Define The Time Scale Over Which Steps 3-6 Are Likely To Occur
Review steps 3-6, looking independently at the element of time. Define and document the time scale over which the effects will occur.	In-channel work, bank stabilization, and revegetation for Phase 1 of the East Yosemite Valley Utilities Improvement Plan would be completed within a 2- to 3-month period during the fall of 2003 (September through November) when the flow of the Merced River is typically lowest (less than 200 cubic feet per second). Other construction within the river is planned in Phase 2 and Phase 3 of the project. All river work will occur during low flow. The overall project duration would be up to 10 years.

§         Biological – Riparian areas and low-elevation meadows are the most productive communities in Yosemite Valley. The high quality and large extent of riparian, wetland, and other riverine areas provide rich habitat for a diversity of river-related species, including special-status species, neotropical migrant songbirds, and numerous bat species.

§         Cultural – The Valley segment contains evidence of thousands of years of human occupation reflected in a large number of archeological sites and continuing traditional use today. Nationally significant historic resources are found here, such as designed landscapes and developed areas, historic buildings, and circulation systems (trails, roads, and bridges) that provide visitor access to the sublime views of natural features that are culturally valuable.

§         Hydrologic Processes – The Valley segment is characterized by a meandering river, world-renowned waterfalls, an active flood regime, oxbows, unique wetlands, and fluvial processes.

Effects of the Selected Alternative on Outstandingly Remarkable Values

The Selected Alternative would result in development of consolidated utility corridors, a reduction in the number of Merced River utility crossings, a reduction of utility infrastructure located within environmentally sensitive areas, and construction of one new Merced River utility crossing. The proposed project has been designed to minimize impacts to the free-flowing character of the Merced River. Indirectly, relocation of the utilities and removal of utilities in the meadow areas designated for ecological restoration will result in enhancement of the river’s biological and hydrologic Outstandingly Remarkable Values. Low-elevation meadows, such as those designated for ecological restoration, are one of the most productive communities in Yosemite Valley. In addition, restoration of the meadow areas will enhance the river’s hydrologic values by providing areas that encourage the river’s active flood regime and fluvial processes. An assessment of the Selected Alternative’s effects on Outstandingly Remarkable Values is provided in table 3-2.

 

Section 7 Determination

The Selected Alternative would develop consolidated utility corridors within less environmentally sensitive areas, reduce the number of Merced River utility crossings, and remove or abandon utilities located in environmentally sensitive areas such as meadows identified for ecological restoration. The Selected Alternative does result in one new Merced River crossing which will be constructed eight feet under the existing riverbed. Riverbed materials will be salvaged and used to return the riverbed to its pre-construction contours. The project has been designed to minimize impacts to free-flowing condition of the river, interference with linkages to tributary inflow and backwater areas, and disruption of contribution of woody debris to the river.

 

The project would have an indirect beneficial effect on the biological and hydrologic Outstandingly Remarkable Values by reducing utility infrastructure within the River Protection Zone and those areas designated for ecological restoration. The ecological restoration is expected to enhance the river’s biological and hydrologic values by improving riverine habitat and allowing the river’s floodplain to expand into historically flooded areas. The National Park Service concludes that the Selected Alternative would enhance free-flow of the Merced River and would not have any direct and adverse effects on the Outstandingly Remarkable Values for which the river was designated Wild and Scenic.

 

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