South Fork Merced River Bridge Replacement Project

Environmental Assessment

Yosemite National Park

Lead Agency: National Park Service

Finding of No Significant Impact

Purpose and Need

This Finding of No Significant Impact (FONSI) documents the decision of the National Park Service to adopt a plan to replace the South Fork Merced River Bridge and the determination that no significant impacts on the human environment are associated with that decision. The National Park Service plans to remove the existing, condemned South Fork Merced River Bridge and reconstruct a bridge that will provide adequate and safe vehicle access, be aesthetically appropriate to the scenic nature of the area, and comply with the guidance of the Merced River Plan by restoring a more natural flow in this reach of the South Fork Merced River.

The South Fork Merced River Bridge is an integral part of Yosemite National Park’s transportation infrastructure, with approximately one-third of the annual visitors entering the park from the south and crossing the bridge. The South Fork Merced River Bridge, constructed in 1931, was determined to have structural deficiencies through inspections in 1992 and 1993. After flooding in 1997 increased concerns over the structural integrity and safety of the bridge, the bridge was permanently closed and a temporary Bailey bridge was installed to convey traffic. The National Park Service intends to remove and replace the condemned structure in order to avoid uncontrolled bridge collapse and resulting environmental consequences. The temporary bridge was not designed for permanent use and would also be removed. A complete description of the plan and its environmental consequences are contained in the South Fork Merced River Bridge Replacement Environmental Assessment.

Selected Action and Alternatives Considered or Analyzed

The South Fork Merced River Bridge Replacement Environmental Assessment analyzed two alternatives, Alternative 1: No Action, and Alternative 2: South Fork Merced River Bridge Replacement (Selected Alternative). These alternatives were developed by the National Park Service based on the  purpose and need, issues raised during scoping, and other public comment. The South Fork Merced River Bridge Replacement Environmental Assessment disclosed the potential environmental consequences that may result from implementation of each alternative. Comments received during the public review of the South Fork Merced River Bridge Replacement Environmental Assessment were considered in the preparation of this FONSI.

Alternative 1: No Action Alternative. Under the No Action Alternative, the South Fork Bridge would remain in its present condition, without replacement, maintenance, or repair. The temporary Bailey bridge would continue to serve as vehicle access into the park. The No Action Alternative provides a baseline from which to compare the Selected Alternative to evaluate the magnitude of proposed changes, and to measure the environmental effects of those changes.

Under the No Action Alternative, no management action would be taken to repair, remove, or replace the bridge. This condition of benign neglect would eventually result in the collapse of a portion of the bridge, causing release of bridge debris into and possible bank erosion of the South Fork Merced River. Further natural resource damage would result from collapse of the utility lines attached to the bridge resulting in raw sewage entering the river and from debris removal activities in the downriver reach following a collapse.

In 1987, a Historic Resource Study concluded that the South Fork Bridge was not eligible for listing due to damage and reconstructions (since the original construction in 1931) that had compromised the architectural and historic integrity of the bridge. In 1995, the California State Historic Preservation Office concurred that “the structure has no strong associations with historic events or persons, nor is it architecturally significant.” In addition, in 1991, through the Yosemite National Park Roads and Bridges Recording Project, the South Fork Bridge was documented to Historic American Engineering Record (HAER) standards, which included historical and descriptive data, measured drawings, and archival photographs (HAER No. CA-113). Such documentation and historic resource determinations have been considered in decisions made relative to the lack of maintenance and repair of the South Fork Bridge.

Selected Alternative. The Selected Alternative identifies removal of the existing triple-span South Fork Bridge and replacement with a new single-span bridge in the same location. The new bridge would be approximately 13-feet wider and 16 feet longer than the old bridge to accommodate wider travel lanes, shoulders, and a new 5-foot-wide sidewalk. The new bridge would span the entire South Fork Merced River without the need for center support piers, thus restoring a more natural flow through this river reach. The appearance of the bridge would be made similar to the existing bridge by incorporating a natural river cobble façade around railing pedestals and interior approach walls and a river rock formliner pattern on the face of the abutments, wingwalls, and exterior approach walls formed from the existing South Fork Bridge pier/abutment rock face. Utility lines attached to the existing South Fork Bridge would be transferred to the temporary Bailey bridge during demolition and removal of the existing bridge and construction of the new bridge. When traffic and utility lines are rerouted onto the new bridge structure, the temporary Bailey bridge would be removed, along with the approaches and temporary abutments, and the site restored. Construction for this project is expected to last approximately 13 months, starting about September 2003, with completion anticipated by October 2004.

A temporary containment system consisting of a reinforced tarp, netting, cage, or floating steel tubs would be positioned beneath the South Fork Bridge to prevent small debris and cement slurry, among other items, from entering the South Fork Merced River. As the bridge is dismantled into small enough segments for safe removal, the containment system would capture errant pieces of material (mostly concrete, rock, and steel) to prevent accidental fall into the river. It would also be left in place during construction activities to capture construction debris and may be anchored to the existing structure or connected to a structural support system. A temporary structural support system, which could include scaffolding, jacks, or mechanical lifts, may be installed to prevent the uncontrolled collapse of the bridge structure during demolition or to anchor the containment system.

Removal and reconstruction of the South Fork Bridge would have short-term demolition- and construction-related impacts on natural, cultural, and social resources. Because demolition and construction would occur in a controlled manner (e.g., within a delineated work area, during low-flow conditions, with the application of Best Management Practices), the Selected Alternative would avoid the more pronounced effects of uncontrolled bridge failure and debris retrieval activities described under Alternative 1. Demolition- and construction-related impacts would be reduced by application of Best Management Practices and resource-specific mitigation measures. Regrading and revegetation upon completion of construction would result in beneficial effects on soils, water quality, and biological resources. The Selected Alternative would restore the free-flowing condition of the South Fork of the Merced Wild and Scenic River in this reach and return it to a more natural condition, thereby enhancing its biological and hydrologic integrity. The Selected Alternative would have a long-term, beneficial effect on natural and scenic resources because it would return the river to a more natural state, restore the active flood regime and fluvial processes, and removal of the temporary Bailey bridge would improve the scenic viewscape of the area.

Alternatives Considered But Dismissed. The National Park Service considered four additional alternatives to the  Selected Alternative that were dismissed from further consideration because they did not meet the project’s purpose and need. These included:

Replace South Fork Merced River Bridge Superstructure Leaving Piers and Abutments in Place. The National Park Service, in consultation with the Federal Highway Administration, determined that the bridge piers have been significantly undermined and are not structurally adequate for supporting a new structure. Further, the piers and abutments do not meet current design standards and leaving the piers within the active channel of the South Fork Merced Wild and Scenic River is not consistent with the goal of the Merced River Plan to protect and restore natural hydrologic and geomorphic processes. Reconstructing with the piers and abutments in place would be economically infeasible as the piers and abutments also need substantial work that would be difficult to accomplish without total tear down.

Use South Fork Bridge as a Pedestrian Bridge and the Temporary Bailey Bridge as a Permanent Replacement. The National Park Service determined that the temporary bridge is not designed for permanent use and is constructed on temporary footings. The constant vibration from use results in loosening of the bolts holding the bridge together and requires frequent ongoing inspections and maintenance. The bridge lanes are too narrow and the restriction causes a reduction in traffic speeds and associated congestion at the entrance to the bridge. Use of the South Fork Bridge for pedestrians would require ongoing maintenance to ensure pedestrian safety. Further, leaving the South Fork Bridge piers within the South Fork Merced Wild and Scenic River is inconsistent with the Merced River Plan goal to protect and restore natural hydrologic and geomorphic processes.

Construct a Triple Span Replacement Bridge. This alternative was dismissed from further consideration since it would not meet one of the primary objectives of the Purpose and Need for the project, which is to restore the free-flowing condition of the river in this area, nor did it meet the goals of the Merced River Plan to protect and restore natural hydrologic and geomorphic processes.

Demolition of the Existing Bridge With No Permanent Replacement. This alternative was dismissed from further consideration since it would not maintain Wawona Road (Highway 41) as the primary access road into the park from points south of the park, consistent with the General Management Plan.

Environmentally Preferred Alternative

The environmentally preferred alternative is determined by applying criteria identified in Section 101 of the National Environmental Policy Act (NEPA) to each alternative considered. In accordance with NEPA, the environmentally preferred alternative would best: (1) fulfill the responsibilities of each generation as trustee of the environment for succeeding generations; (2) assure for all generations safe, healthful, productive, and esthetically and culturally pleasing surroundings; (3) attain the widest range of beneficial uses of the environment without degradation, risk of health or safety, or other undesirable and unintended consequences; (4) preserve important historic, cultural, and natural aspects of our national heritage and maintain, wherever possible, an environment that supports diversity and variety of individual choice; (5) achieve a balance between population and resource use that will permit high standards of living and a wide sharing of life’s amenities; and (6) enhance the quality of renewable resources and approach the maximum attainable recycling of depletable resources.

The National Park Service has considered both alternatives in this analysis in accordance with NEPA and Council on Environmental Quality regulations (Section 1505.2) and has determined that the Selected Alternative, Alternative 2 as presented in the South Fork Merced River Bridge Replacement Environmental Assessment, is environmentally preferable based on its furtherance of the following National Environmental Policy Act goals as evaluated below.

§         NEPA Section 101 Requirement 1. “Fulfill the responsibilities of each generation as trustee of the environment for succeeding generations.”

The Selected Alternative will best fulfill the responsibilities of each generation as trustee of the environment for succeeding generations because of its protection and restoration of the hydrologic and geomorphic processes in the South Fork of the Merced Wild and Scenic River in relation to Alternative 1, the No Action Alternative. Although short-term, negligible to minor, construction-related, adverse impacts could occur for all resource areas during implementation of the Selected Alternative, there will be long-term, negligible to minor, beneficial impacts on soils, hydrologic processes and water quality, wetlands, vegetation, wildlife, air quality, soundscapes and noise, socioeconomics, transportation, visitor experience and recreation, scenic resources, and park operations and facilities. The Selected Alternative is expected to have long-term, minor to moderate, beneficial impacts on special-status species and negligible to minor adverse impacts to archeological and ethnographic resources.

Under the No Action Alternative, continued deterioration of the existing South Fork Bridge, continued use of the temporary Bailey bridge, and eventual collapse of the South Fork Bridge would have short-term, negligible to minor, adverse impacts to vegetation, wildlife, air quality ethnographic resources, transportation, and scenic resources; minor to moderate adverse impacts to soil resources, wetlands, and special-status species; and, moderate to major adverse impacts to hydrologic processes, park operations and facilities, and visitor experience.  

While in the longer term after the bridge debris from the collapse has been removed, the impacts would be negligible to minor adverse for vegetation and ethnographic resources; minor to moderate and adverse for soil resources and wetlands; and negligible to minor beneficial for hydrologic processes, wildlife, special-status species, and scenic resources.

Due to the degraded condition of the existing bridge and the potential for eventual collapse, the Selected Alternative of bridge replacement best fulfills the responsibility of this generation as trustee of the environment for future generations.

§         NEPA Section 101 Requirement 2. “Assure for all Americans safe, healthful, productive, and aesthetically and culturally pleasing surroundings.”

Replacement of the existing narrow bridge that causes reduced traffic speeds and associated delays during busy periods and eliminates the ability for pedestrians to cross the river, and removal of the temporary Bailey bridge, which is an intrusion on the scenic landscape, assures safe, healthful, productive and aesthetically pleasing surroundings. 

§         NEPA Section 101 Requirement 3. “Attain the widest range of beneficial uses of the environment without degradation, risk of health or safety, or other undesirable and unintended consequences.”

Replacement of the South Fork Merced River Bridge and removal of the temporary Bailey bridge under the Selected Alternative will attain the widest range of beneficial uses of the environment without degradation. The replacement bridge will allow restoration of the free flow of the South Fork of the Merced Wild and Scenic River while providing a safe and effective means of crossing the river for both vehicular and pedestrian traffic.  Controlled demolition of the existing South Fork Bridge will also prevent the potential for moderate to major environmental degradation in the vicinity of the site as a result of an uncontrolled collapse of the bridge.

Under the No Action Alternative, the continued use of the temporary Bailey bridge would continue to allow a structure that does not fit with the scenic landscape. Placement of two bridges and the continued existence of in-river piers as an impediment to flow in the South Fork Merced Wild and Scenic River would continue to result in degradation to the environment. The No Action Alternative would also result in degradation to the environment, risk to health and safety, or other undesirable or unintended consequences as a result of an uncontrolled collapse of the bridge through continued scouring of the bridge piers. 

§         NEPA Section 101 Requirement 4. “Preserve important historic, cultural, and natural aspects of our national heritage and maintaining, wherever possible, an environment that supports diversity and variety of individual choice.”

The Selected Alternative will preserve the natural aspects of the areas by restoring the view corridor, which now includes the temporary Bailey bridge, and restoring the unimpeded hydrologic flows of the South Fork Merced Wild and Scenic River.  Both the No Action Alternative and the Selected Alternative could have the potential for short-term, negligible to minor, adverse impacts to archeological and ethnographic resources due to the potential for erosion under existing conditions or disturbance during construction activities associated with the bridge replacement. The potential for bridge collapse and subsequent bank erosion could result in minor to moderate adverse impacts to archeological resources in the vicinity. All impacts will be mitigated through planning and compliance actions performed in accordance with stipulations in the park’s 1999 Programmatic Agreement.

§         NEPA Section 101 Requirement 5. “Achieve a balance between population and resource use that will permit high standards of living and a wide sharing of life’s amenities.”

The No Action Alternative would continue to result in traffic delays, and would continue to impede the river flows causing impacts to aquatic resources and increasing the potential for flooding and erosion. The Selected Alternative will remove the flow impediments and restore the free-flowing conditions of the river while improving traffic flows crossing the river, and maintaining the bridge and Wawona Road (Highway 41) as a significant transportation route from the south entrance of the park. The new bridge will also allow pedestrian traffic. The Selected Alternative will better achieve a balance between population and resource use of the river.

§         NEPA Section 101 Requirement 6. “Enhance the quality of renewable resources and approaching the maximum attainable recycling of depletable resources.”

The Selected Alternative will result in enhanced quality of the South Fork Merced River through removal of the existing bridge piers as restrictions to flow. In addition, the Selected Alternative will result in improved traffic flows and minimizing impacts to air quality from traffic slowing or stopping to wait to cross the temporary bridge.

The No Action Alternative would result in continued deterioration of the bridge structure and eventual collapse.  As a result, the bridge removal activities would occur in the river and some or all of the bridge structure may not be retrievable or recyclable. The Selected Alternative will result in controlled bridge removal and the ability to recycle bridge materials to the extent possible.

In conclusion, upon full consideration of the elements of Section 101 of NEPA, the Selected Alternative  represents the environmentally preferable alternative for the South Fork Merced Wild and Scenic River Bridge. After review of potential resource and visitor impacts and developing mitigation for impacts to natural and cultural resources, the Selected Alternative achieves the greatest balance between the need to maintain a permanent travel route through this area, the need to restore natural hydrologic and geomorphic processes in the Merced Wild and Scenic River in accordance with the Merced River Plan, and the protection and preservation of natural and cultural resources and visitor experience in the park.

Why the Selected Alternative Will Not Have a Significant Effect on the Human Environment

Under the Selected Alternative, there will be a long-term, negligible to minor, beneficial impact on soils due to removal of the instream bridge structures and site restoration and stabilization. The site restoration and stabilization would repair eroded areas and increase protection of riverbanks, adjacent trails, and Wawona Road. The Selected Alternative would result in long-term, minor, beneficial impacts with respect to geologic hazards due to updated seismic engineering design standards.

Overall, there will be a long-term, negligible to minor, beneficial impact on hydrology and water quality due to the avoidance of bridge collapse and associated bank erosion, localized flooding and rupture of sewage lines, and the removal of the bridge abutments from creek channels to accommodate hydrologic flows.

Under the Selected Alternative, there will be long-term, negligible to minor, and beneficial impact on wetlands due to the removal of bridge piers from river channels. The project complies with Executive Order 11990 (Protection of Wetlands) and Department of the Interior - Director's Order 77-1: Protection of Wetlands.

Overall, impacts to vegetation will be long-term, negligible to minor, and beneficial due to the controlled removal of the South Fork Bridge and revegetation of any construction or erosion related features. Short-term construction related impacts to vegetation will be mitigated by keeping construction zones to the smallest extent possible, limiting equipment size, avoiding tress, shrubs, and herbaceous vegetation to the extent possible, controlling the importation of non-native plant species, developing revegetation and restoration plans, and monitoring the success of these plans.

Impacts to wildlife from implementation of the Selected Alternative will be long-term, minor, and beneficial. The removal of the instream bridge piers and restoration of the instream and riverbank habitat will be beneficial for a diversity of river-related species.

A total of 60 special-status species (55 wildlife and 5 plant species) have been considered in the evaluation of the South Fork Merced River Bridge Replacement Project. Species evaluated include federally listed threatened or endangered species; species of concern; state-listed threatened, endangered, and rare species; and species that are locally rare or threatened that are known to be or could be present within the planning area. Of the special-status species evaluated, the project area contains suitable habitat for 32 special-status plant and wildlife species. Of those species with suitable habitat, only the Wawona riffle beetle and nine species of bats are known or likely to occur in the project area.

Bridge removal under the Selected Alternative would have localized, short-term, minor, adverse impacts on the Wawona riffle beetle and the potential habitat for the California red-legged frog, northwestern and southwestern pond turtles, and foothills yellow-legged frog. 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 and lubricants).  The Selected Alternative would also have localized, short-term, minor, adverse impacts on the nine species of bats as a result of the use of heavy equipment and human intrusion and could include disruption of breeding activities.  Bridge removal activities could have a short-term, localized, negligible to minor, adverse impact to the habitat for special-status birds and mammals, related to heavy equipment use and could include increased dust, vegetation removal, and noise. The Selected Alternative could have short-term, localized, negligible, adverse impacts on habitat suitable for special-status plants, primarily as a result of heavy equipment use and placement of cofferdams and could include soil disturbance, soil compaction, dust, vegetation removal, root damage to adjacent vegetation, and the introduction and spread of non-native plant species. Mitigation measures described in the South Fork Merced River Bridge Replacement Environmental Assessment would minimize the potential for impacts to these species or their habitat.

Over the long term, the bridge replacement, revegetation and restoration of the free-flowing condition of the South Fork Merced Wild and Scenic River would result in localized beneficial impacts ranging from negligible to minor for most species and minor to moderate for the nine species of bats.

Local, short-term, negligible to minor, adverse impacts are anticipated to air quality from demolition/construction activities associated with the Selected Alternative. In the long term, the project would have local, negligible to minor, beneficial impacts on air quality as the Selected Alternative would alleviate some congestion, allowing vehicles to travel smoothly through the area at a higher rate of speed.

The demolition/construction of the South Fork replacement bridge is anticipated to have local, short-term, adverse impacts on the noise environment. Over the long term, the noise environment would be shaped by natural sound interspersed with human-caused sources of noise (i.e., motor vehicles, human voices, and aircraft).

Cultural resources consist of archeological sites, ethnographic sites, and cultural landscapes. Under the Selected Alternative, impacts to archeological sites found in the vicinity of the South Fork Bridge will be local, long-term, minor, and adverse due to ground disturbing activities. The potential level of adverse effects associated with the Selected Alternative would be minimized or avoided through the use of archeological and American Indian monitors and implementation of other mitigating measures, as necessary. All mitigation would be implemented in consultation with the California State Historic Preservation Office and American Indian tribes, as appropriate. There is a low probability of unknown archeological resources in the project vicinity and a known site in the vicinity has been the subject of a data recovery plan implemented under the guidance of the California State Historic Preservation Office.

There are traditionally gathered plant species present in the South Fork Bridge locality.  The Selected Alternative would result in local, negligible, adverse impacts to the traditional plant gathering activities. Any site-specific planning and compliance actions would be accomplished in accordance with stipulations in the 1999 Programmatic Agreement and the park would continue to consult with culturally associated American Indian tribes under this agreement and the cooperative agreement for traditional uses.

The South Fork Bridge is not a contributing element to the cultural landscape due to changes made to the bridge that compromised the original architecture. The Selected Alternative poses no adverse impact to significant historic resources throughout the remainder of the Wawona area.

The Selected Alternative would have a direct and indirect economic impact, which would result in a local and regional, short-term, negligible to minor, beneficial impact to the socioeconomics of Wawona and Mariposa County.

Overall, the Selected Alternative would result in local, long-term, negligible, beneficial impacts to transportation as a result of decreased traffic congestion and increased speed at which vehicles cross the replacement bridge. Short-term, minor adverse impacts on transportation will occur as a result of traffic delays associated with the bridge construction. Closure of the shuttle bus parking overflow lot to privately owned vehicles would have local, short-term, minor, adverse impacts on the availability of parking near the South Fork Bridge. 

Visitor experience will be affected locally in a negligible beneficial manner over the long term as the sidewalk allows pedestrian access across the bridge and the removal of the bridge piers increases recreation opportunities.  Over the short term, during bridge construction, there will be negligible to minor adverse impacts to recreation and pedestrian activities.

Scenic resources will experience minor beneficial impacts as a result of the removal of the temporary Bailey bridge and the deteriorated existing South Fork Bridge and replacement with a new structure.

 The Selected Alternative would result in short- and long-term, moderate, beneficial impacts to park operations from eliminating safety hazards associated with pedestrian use of the condemned/closed existing bridge, and substantially reducing the potential for a catastrophic bridge failure. Short-term localized disruptions to park operations can be expected during construction and will cause impacts ranging from negligible to moderate as a result of disruptions to utility lines during moving, and the need for potential staff to oversee the bridge construction.

The South Fork Merced River Bridge Replacement Environmental Assessment analyzed cumulative impacts of the South Fork Merced River Bridge Replacement Project, and in no case were cumulative impacts considered significant. No elements of precedence have been identified, and implementation of the Selected Alternative will comply with federal, state, and local environmental protection laws.

Non-Impairment of Park Resources

§         necessary to fulfill specific purposes identified in the establishing legislation or proclamation of Yosemite National Park,

§         key to the natural or cultural integrity of Yosemite National Park or to opportunities for enjoyment of the park, and

§         identified as a goal in the park’s General Management Plan or other relevant National Park Service planning documents.

The Selected Alternative will cause short-term adverse construction-related impacts and negligible or minor adverse impacts to certain resources. The magnitude of these impacts is not sufficient to impair park resources. Consequently, implementation of the  Selected Alternative will not violate the National Park Service Organic Act of 1916.

Mitigation

To ensure that implementation of the proposed project protects natural and cultural resources, Outstandingly Remarkable Values, and the free-flowing condition of the South Fork Merced Wild and Scenic River through this reach, a consistent set of mitigation measures would be applied. As part of the environmental review, the National Park Service would avoid, minimize, and mitigate impacts to the extent practicable. As such, the project shall avoid or minimize impacts to natural and cultural resources and be designed to work in harmony with the surroundings. The project shall reduce, minimize, or eliminate air and water nonpoint source pollution. The project shall be sustainable whenever practicable by recycling and reusing materials, minimizing materials, and minimizing energy consumption during the project. The following mitigation measures (table 1-1) have been incorporated into the project to avoid or reduce impacts to park resources.

Impact Topic	Mitigation Measure	Responsibility	Critical Milestones
Best Management Practices	The project will avoid or minimize impacts to natural and cultural resources. The project will be designed to work in harmony with the surroundings, particularly the Yosemite Valley and Wawona area Cultural Landscapes. The project will reduce, minimize, or eliminate air and water nonpoint-source pollution. The project will be sustainable whenever practicable, by recycling and reusing materials, by minimizing materials and by minimizing energy consumption during the project.	Yosemite National Park, Project Manager Contractor	Prior to and concurrent with project activities
	The National Park Service project manager shall ensure that the project remains confined within the parameters established in the compliance document, U.S. Army Corps of Engineers Section 404 Permit, etc. The National Park Service project manager shall ensure that mitigation measures are properly implemented.	Yosemite National Park, Project Manager	Concurrent with project activities
	A natural resource protection program shall be implemented using standard measures such as construction scheduling, erosion and sediment control, use of fencing or other means to protect resources adjacent to the project area, removal of all food-related items or rubbish to bear-proof containers, regrading, and revegetation. Food shall be stored in accordance with park regulations.	Yosemite National Park, Project Manager Contractor	Concurrent with project activities
	Small, wheeled or tracked equipment shall be allowed to enter the river to assist in the placement of a containment system and a structural support system or to remove demolition debris from the river. To protect the riverbank, this equipment shall be lifted from the riverbank by crane and placed on the riverbed, or shall be driven on a ramp into the riverbed. Heavy equipment used within the bed and banks of the South Fork Merced River will be placed on mats, or other measures will be taken to minimize disturbance.	Contractor	Concurrent with project activities
	The load limit and equipment size will be restricted to protect nearby utility lines and established native vegetation.	Yosemite National Park, Project Manager	Concurrent with project activities
	All construction equipment will be stored within the delineated work limits and/or at the construction staging area.	Contractor	Concurrent with project activities
	Measures to reduce the effects of demolition and construction on visitor safety and experience will be implemented. Visitors, contractors, and park personnel will be safeguarded from demolition and construction activities. A barrier plan indicating locations and types of barricades will be used to protect public health and safety.	Yosemite National Park, Project Manager	Prior to and concurrent with project activities
	An emergency notification program will be in place to notify utilities and emergency response units prior to relocation or demolition, identify locations for utilities prior to construction, etc.	Yosemite National Park, Project Manager	Prior to and concurrent with project activities
	All tools, equipment, barricades, signs, surplus materials, and rubbish will be removed from the project work limits upon project completion. Any asphalt surfaces damaged due to work on the project will be repaired to original condition. All demolition debris will be removed from the project site, including all visible concrete and metal pieces.	Contractor	Upon completion of project activities
	Disturbed areas will be graded and raked smooth to eliminate tire tracks and tripping hazards.	Contractor	Upon completion of project activities
Geology, Geohazards, and Soils	Erosion and sediment controls will be provided.	Contractor	Prior to and concurrent with project activities
	Topsoil will be removed from areas of construction and stored for later use in reclamation.	Contractor	Prior to and concurrent with project activities
Hydrology, Water Quality, and Floodplains	Demolition debris larger than 2 inches in any dimension that inadvertently falls into the river will be removed during demolition and construction.	Contractor	Concurrent with project activities
	A spill prevention and pollution control program for hazardous materials will be implemented. An adequate hydrocarbon spill containment system shall be available onsite in case of unexpected spills in the project area.	Yosemite National Park, Project Manager Contractor	Prior to and concurrent with project activities
	Storm water management measures shall be implemented, as necessary, to reduce nonpoint source pollution discharge from paved and other impervious surfaces.	Yosemite National Park, Project Manager Contractor	Prior to and concurrent with project activities
	The demolition and construction will comply with provisions of the California Regional Water Quality Control Board, Central Valley Region, and the U.S. Army Corps of Engineers 404 permit.	Yosemite National Park, Project Manager	Prior to and concurrent with project activities
Vegetation	Avoid trees, shrubs, and herbaceous vegetation growing onsite to the maximum extent possible, using temporary barriers for protection, as necessary.	Contractor	Concurrent with project activities
	A maximum of 10 mature trees would be removed  within the construction zone. Remove trees outside of the construction area only if absolutely necessary, and then only following consultation between the construction supervisor and appropriate park staff.	Yosemite National Park, Project Manager Contractor	Concurrent with project activities
	Do not fasten ropes, cables, or fencing to trees.	Yosemite National Park, Project Manager Contractor	Concurrent with project activities
	Immediately treat trees damaged during construction activities with sodium tetraborate decahydrate to prevent root rot infection.	Yosemite National Park, Project Manager	Concurrent with project activities
	The National Park Service will prepare a prescription for revegetating any disturbed areas (including riverbanks) to be included in the construction specifications.	Yosemite National Park, Project Manager	Prior to and concurrent with project activities
	Control the importation of non-native plant species through steam cleaning of heavy equipment, weed-free certification of seeds and cover materials, identification of non-native species in the vicinity prior to construction, and revegtation with appropriate native species.	Yosemite National Park, Project Manager Contractor	Prior to and concurrent with project activities
	Frequently monitor reclaimed areas after construction to determine if reclamation efforts are successful or if additional remedial actions are necessary.	Yosemite National Park, Project Manager	Upon completion of project activities
Wetlands	Ensure that permanent structures associated with new bridge construction are located outside of wetland boundaries.	Yosemite National Park, Project Manager	Concurrent with project activities
Wildlife – Bird Species	Conduct activities outside of the breeding season.	Yosemite National Park, Project Manager	Concurrent with project activities
	Remove trees or structures with unoccupied nests prior to March 1, or following the nesting season. If any special-status species is observed nesting, a determination will be made as to whether or not the project will impact the active nest or disrupt reproductive behavior. If it is determined that the activities will not impact an active nest or disrupt breeding behavior, work shall proceed without restriction or additional mitigative measures. If it is determined that bridge removal/construction activities will impact an active nest or disrupt reproductive behavior, then avoidance strategies will be implemented.	Yosemite National Park, Project Manager Contractor	Prior to and concurrent with project activities
Wildlife – Special-Status Aquatic Species	Work activities within potential special-status aquatic species habitat will be completed during low-flow conditions.	Contractor	Concurrent with project activities
	All work adjacent to or within aquatic habitats will be regularly monitored.	Yosemite National Park, Project Manager	Concurrent with project activities
	All fueling and maintenance of vehicles and equipment will occur outside any aquatic habitat.	Contractor	Concurrent with project activities
	The total area of activity will be limited to the minimum necessary to achieve the project goal, as determined collaboratively with contractors and National Park staff.	Yosemite National Park, Project Manager Contractor	Concurrent with project activities
	During dewatering, the intake will be completely screened with wire mesh not larger than 5 millimeters to prevent aquatic species from entering the system. Water will be released or pumped downstream at an appropriate rate to maintain downstream flows during work. Upon completion of activities, barriers to flow will be removed in a manner that allows flow to resume with the least disturbance to the substrate.	Yosemite National Park, Project Manager Contractor	Concurrent with and upon completion
Wildlife – Special-Status of Bats	A qualified biologist will conduct surveys in the summer and immediately prior to bridge removal/construction to determine whether trees or other habitat that would be affected by the project provides hibernacula or nursery colony roosting habitat.	Yosemite National Park, Project Manager	Prior to and concurrent with project activities
	If summer surveys reveal that the site is being used as a nursery colony, the project will not occur until after August 15, when the pups are weaned and are able to fly.	Yosemite National Park, Project Manager	Prior to and concurrent with project activities
	If surveys conducted immediately prior to bridge removal/construction do not reveal any bat species present within the project area, the action will begin within three days to prevent the destruction of any bats that could move into the area after the survey.	Yosemite National Park, Project Manager	Prior to and concurrent with project activities
	Snags will not be removed without prior approval from a National Park Service wildlife biologist and/or plant ecologist. Riparian vegetation will be retained to the extent possible to preserve important foraging habitat.	Yosemite National Park, Project Manager Contractor	Prior to and concurrent with project activities
Air Quality	A dust abatement program will be implemented. Construction contractors will implement measures to reduce fugitive emissions including the watering of active work areas, covering of loads of demolition debris and other materials that would blow from a moving vehicle, cleaning construction debris from paved areas, covering of stockpiles, and limiting speeds on unpaved roads.	Yosemite National Park, Project Manager Contractor	Prior to and concurrent with project activities
	Vehicle emission controls will be implemented.	Yosemite National Park, Project Manager Contractor	Prior to and concurrent with project activities
Cultural Resources	An archeologist and American Indian monitor will be present during ground-disturbing activities.	Yosemite National Park, Project Manager	Concurrent with project activities
	Construction workers will be advised of appropriate actions should cultural resources be encountered during project construction.	Yosemite National Park, Project Manager	Concurrent with project activities
	If previously unknown cultural resources are uncovered during construction, all work shall be halted in the discovery area and the National Park Service shall consult in accordance with 36 CFR 800.11 and, as appropriate, provisions of the Native American Graves Protection and Repatriation Act.	Yosemite National Park, Project Manager Contractor	Concurrent with project activities
	All bridge work will be conducted in accordance with the 1999 Programmatic Agreement and Appendix E of the Yosemite Valley Plan.	Yosemite National Park, Project Manager Contractor	Concurrent with project activities
	Any architectural elements of the South Fork Bridge that are determined to be feasible to salvage will be salvaged.	Yosemite National Park, Project Manager Contractor	Prior to and concurrent with project activities
Visitor Experience	No demolition/construction work will be allowed on weekends or federal government holidays without prior written approval of the Superintendent. To minimize visitor impacts associated with noise, work hours will be between 8:00 A.M. and 5:00 P.M. unless other hours are approved by the Superintendent.	Yosemite National Park, Project Manager	Concurrent with project activities
	Standard noise abatement measures will be implemented during demolition including use of best available noise control techniques and location of stationary noise sources to minimize impacts to sensitive public use areas.	Contractor	Concurrent with project activities
	Vehicle traffic flow will be maintained as much as possible during construction with delays of no longer than a maximum of 30 minutes.	Yosemite National Park, Project Manager Contractor	Concurrent with project activities

Public Involvement and Coordination

Public Involvement

On September 20, 2002, the Yosemite National Park Superintendent mailed a letter announcing the resumption of the planning process for the removal and replacement of the South Fork Bridge. This letter was sent to individuals and organizations on the Yosemite National Park

mailing list, and background, timeline, and public involvement information was published on the park Web site. The letter also detailed the time, location, and purpose of a public meeting for the project. Press releases describing the proposed action and requesting comments were issued during September 2002.

On October 23, 2002, the National Park Service held a public meeting at the Yosemite Valley Visitor Center, East Auditorium, to discuss several planning projects, including the South Fork Merced River Bridge Replacement Project, with interested citizens. The purpose of the meeting was to: (1) provide participants with an overview of existing conditions and the proposed action, (2) ask participants to identify key issues that should be analyzed during the environmental review and compliance process, and (3) provide an opportunity for participants to ask questions regarding project alternatives and the overall environmental review and compliance process. Approximately 131 individuals attended this meeting. Since that time, the project has been included in the monthly open houses held at the park on February 26, 2003; March 28, 2003; April 23, 2003; and May 21, 2003 (Yosemite Valley Visitor Center, East Auditorium) to discuss all upcoming park projects and has been included in the quarterly Planning Update newsletters for Yosemite National Park issued in September 2002, January 2003, and April 2003.

 

Results of Scoping

 

Public notice to interested agencies and the public was released on September 20, 2002. Approximately 7,724 scoping notices were sent to individuals, groups, or organizations with a potential interest in the project. Scoping comments were received through October 26, 2002. As a result of the scoping effort, 10 responses were received. Most of the scoping comments supported bridge replacement with concerns expressed regarding the new bridge construction and final appearance. All comments received in response to the scoping notices have been duly considered and will remain in the project record throughout this planning process.

 

Public Comment

 

The South Fork Merced River Bridge Replacement Environmental Assessment was released for a 30-day public review period beginning on April 25, 2003, and closed on May 29, 2003. In addition, the National Park Service held regular Open Houses to disseminate information and collect informal written comments on the South Fork Bridge Replacement Project and other projects. Comments received during the formal public comment period consisted of 11 letters, emails, and faxes from individuals and organizations with a total of 21 comments. Though the 2003 environmental assessment process supersedes the 1996 Removal and Replacement of the South Fork Bridge Environmental Assessment and Finding of No Significant Impact, comments collected as part of the earlier process were considered.

 

Issues raised in public comments included impacts on river resources, historic resources, effects on those who live and work near the bridge, and questions and comments on the bridge structural design. None of the comments received introduced substantive new information nor raised any issues not fully considered in the South Fork Merced River Bridge Replacement Environmental Assessment. No modifications to the Selected Alternative were made as a result of comments. Several of the public comments received provided additional nonsubstantive information or requested additional clarification. The information has been added to the Environmental Assessment through an Errata , which is to be attached to the Environmental Assessment. The Errata sheets provide clarification of the bridge construction and location of utility lines, change the low-flow criteria for allowing work in the river, add a discussion of the designation of the river as Wild Trout Water under the California Department of Fish and Game, change language relative to the requirement for preparation of a management plan for the Merced Wild and Scenic River, and include several new references and definitions.

 

 

Coordination

[1]

California State Historic Preservation Office

The South Fork Merced River Bridge and surrounding resources have been the subject of previous evaluation and mitigation actions. The bridge is located within the boundaries of both the Wawona Cultural Landscape and the Wawona Archeological District. However, the bridge is not eligible for listing in the National Register of Historic Places due to damage and reconstructions since its original construction in 1931 that have compromised its architectural and historic integrity. The California State Historic Preservation Office concurred with this finding by letter dated July 24, 1995. In 1991, the bridge was documented to HAER standards, which included historical and descriptive data, measured drawings, and archival photographs. In accordance with the protocols agreed upon by Yosemite National Park and the California State Historic Preservation Office on March 20, 1997, the current level of documentation for the South Fork Merced River Bridge was determined sufficient.

One archeological site, CA-MRP-171, lies within the proposed project area. This archeological site is well known and has been of interest to the professional archeological community, as well as the general public, minimally since the formation of the park. Beginning in 1994, the National Park Service initiated formal consultation with the California State Historic Preservation Office regarding this site, in preparation for the proposed removal of the South Fork Bridge. Consequently, the site has been formally determined eligible for listing in the National Register of Historic Places as a contributing element of the Wawona Archeological District. Based on the results of test excavations and construction monitoring in 1984, and the subsequent development of an appropriate research approach and scope of work, the California State Historic Preservation Office in 1994 concurred with a data recovery plan to mitigate the adverse effects to the archeological site by the proposed bridge replacement project. Execution of the data recovery plan would result in a determination of no adverse effect for the site. Archeological monitoring at the site was undertaken in April 1998, during the installation of the temporary Bailey bridge. The data recovery report ^[2] states that it “constitutes sufficient mitigation and a finding of no adverse effect for the proposed undertaking.” This is because the data recovery was undertaken within the constructs of the 1979 Memorandum of Agreement. The data recovery document reiterates that an Inadvertent Discovery Plan and archeological monitoring is recommended for the remaining bridge demolition and construction work. Mitigation measures outlined for the Selected Alternative include procedures for an inadvertent discovery and a requirement that an archeological monitor be present during ground disturbing activities. The data recovery report was transmitted to the California State Historic Preservation Office in the fall of 2000.

Removal of the South Fork Bridge would comply with the requirements in Appendix H (Historic Preservation Memorandum of Understanding 1999) of the Merced River Plan. This Programmatic Agreement is between the National Park Service at Yosemite, the California State Historic Preservation Office, and the Advisory Council on Historic Preservation regarding planning, design, construction, operations, and maintenance activities at Yosemite National Park. The National Park Service received final concurrence on removal of the South Fork Bridge, the Selected Alternative, from the California State Historic Preservation Office by letter dated July 7, 2003.

Native American Consultation

Conclusion

Recommended:

Superintendent, Yosemite National Park                                                     Date

Approved:

Director, Pacific West Region, National Park Service                  Date