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Chapter 2
Description of Proposed Action and Alternatives
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This environmental assessment addresses actions of the Lower Yosemite Fall Project that were approved in the Yosemite Valley Plan, including those that have changed slightly since the time the Yosemite Valley Plan Record of Decision was signed (NPS 2000c). A few of the actions approved by the Yosemite Valley Plan were changed because new information became available as the site design was refined for the Lower Yosemite Fall Project.

Alternatives Development

The Yosemite Valley Plan evaluated a full range of alternatives, and its Record of Decision approved actions to proceed. However, as implementation of the Lower Yosemite Fall Project began, it was recognized that additional NEPA compliance was necessary. Consequently, actions evaluated in this environmental assessment are limited to those meeting any of the four criteria listed in Chapter 1 (page 1-5).

Overview of the Alternatives

This section presents three alternatives for the Lower Yosemite Fall Project. Under Alternative 1 (No Action), the Lower Yosemite Fall area would remain unchanged, except for normal maintenance and repair such as rebuilding Bridge #6, which recently collapsed. Alternative 2 (Preferred) would implement approved Yosemite Valley Plan actions for the Lower Yosemite Fall area and clarifies and adjusts certain actions. The need for these adjustments became evident as detailed site-specific planning for the area was undertaken. Alternative 3 (As Evaluated in the Yosemite Valley Plan) presents the actions for the Lower Yosemite Fall area as they were approved in the Yosemite Valley Plan Record of Decision.

Under Alternative 1, the existing conditions in the Lower Yosemite Fall area would be maintained as described in Chapter 3, Affected Environment. Figure 2-1 is the site plan for this alternative. Alternative 1 provides a baseline from which to compare Alternatives 2 and 3, evaluate the magnitude of proposed changes, and measure the environmental effects of those changes. This no action concept follows the guidance of the Council on Environmental Quality, which describes the No Action Alternative as representing no change from the existing management direction or level of management intensity. Listed below are the baseline conditions of the actions that comprise the Lower Yosemite Fall Project.

• Restroom Location. The restroom would remain in its current location and condition. Routine maintenance activities would continue, including the replacement of 2,890 feet of sewer line to the existing restroom. The necessary environmental compliance for the sewer line replacement project has been completed, and the project was approved on April 24, 2001.
  
• Parking Area. The existing parking area would remain in its current location and condition.
  
• Shuttle Bus Stop. The shuttle bus stop would remain at its current location in the Lower Yosemite Fall area.
  
• Tour Bus Unloading, Loading, and Parking. Tour buses would continue to unload and load passengers within the parking area. Tour bus parking would not be relocated from the Lower Yosemite Fall area, replacement parking spaces would not be needed for tour buses that currently park in this area, nor would an interim bus passenger loading and unloading location be necessary. Tour buses would continue to park in the parking area.
  
• Trail Alignment, Including Relocation of the Eastern Trail Near Bridge #1. Trails providing access to the base of Lower Yosemite Fall would remain in their current alignments.
  
• Rehabilitation of Trails. All trails in the Lower Yosemite Fall area would remain in their current condition (including routine maintenance). The trails to the base of Lower Yosemite Fall would not meet federal accessibility standards. Limited interpretive exhibits would remain in their current condition. Stock (e.g., horse) users would share trails with hikers through the Lower Yosemite Fall area.

• Rehabilitation, Relocation, and Installation of Bridges. All bridges would remain in their current locations and condition with the exception of Bridge #6. This bridge, which recently collapsed, would be rebuilt. Bridge abutments would remain in their current locations within the creek bed. The bridge across Yosemite Creek at the base of Lower Yosemite Fall and the viewing platform area would remain in their current condition.
• View Corridor Maintenance. Two historic view corridors through the Lower Yosemite Fall area would not be programmatically maintained through selective trimming of trees and tree removal. Vegetation would be more likely to continue to grow in these view corridors, thus potentially obscuring historic views.
• Removal of Human-Built Rock-Rubble Pile. The existing rock-rubble pile would remain.

Alternative 2 would implement actions approved in the Yosemite Valley Plan for the Lower Yosemite Fall area, including modifications. The site plan for Alternative 2 is provided in figure 2-2. The actions, as well as those approved in the Yosemite Valley Plan, are described below.

• Restroom Relocation. The restroom north of the existing parking area would be removed, and a new restroom would be constructed near what is currently the southeastern edge of the parking lot. The location proposed for the restroom is about 540 feet west of the site identified for the restroom in the Yosemite Valley Plan (see figure 2-3). The change of location would minimize impacts to an ethnographic resource, keep the restroom out of Yosemite Falls view corridors, and be adjacent to the proposed seating/picnic area. The new restroom would be adequately sized for the expected volume of visitors to the area and would be designed to be accessible to persons with mobility impairments. It would contain 12 toilet and four urinal fixtures, including two family-accessible rooms, and two wheelchair-accessible stalls (one men’s, one women’s).
• Parking Area Removal and Establishment of a Small Seating and Picnic Area. The existing parking area (see figure 2-1) would be removed. Trails would be built to approach the western trail to the base of Lower Yosemite Fall, and there would be a small picnic area and seating area with informal seating on benches, logs, or stones. The picnic area would be located on what is currently the southern portion of the parking area and would include up to 12 picnic tables. A trail would provide access to the picnic tables. The remainder of the area would be revegetated with locally native plants.

The following actions would remain unchanged from those approved in the Yosemite Valley Plan:

• New Shuttle Bus Stop. A new shuttle bus stop would be located on the north side of Northside Drive east of the Yosemite Creek Bridge.
• Interim Tour Bus Unloading, Loading, and Parking. To address removal of the tour bus loading/unloading and parking area from the Lower Yosemite Fall area, replacement loading/unloading and parking spaces would need to be provided for tour buses. Long-term tour bus loading and unloading would occur at the future new transit center in Yosemite Village. For an interim time period, bus passenger loading and unloading zone would be provided along Northside Drive near Cook’s Meadow, using the existing turnout west of Village Drive. Until day tour bus parking can be provided elsewhere, as called for in the Yosemite Valley Plan, day tour buses would for the interim park in an existing lane of Northside Drive, extending west of Camp 4. Day tour buses would park in the north (right) lane of the road until passengers are ready for pickup. When passengers are ready to load, buses would return to Northside Drive near Cook’s Meadow for passenger pickup. Interim parking for the few overnight tour buses would be provided in existing parking areas associated with nearby lodging facilities in Yosemite Valley.
• Trail Alignment, Including Relocation of the Eastern Trail Near Bridge #1. A realigned trail with elevated boardwalks would be placed between Bridges #1 and #2 and northwest of Bridge #1. This would minimize impacts to the millrace feature within Hutchings sawmill site because the boardwalks would be placed above the site. All bridge abutments would be moved out of the creek channel to adjacent upland areas. One pier would be placed in the creek at Bridge #3 to support the longer span, and two piers would be in the creek at Bridge #6 to support the longer span. Two piers in the creek at the Yosemite Falls Bridge would be replaced at the same location. Trail alignments between Bridge #6 and the Hutchings view corridor would be designed to minimize impacts to ethnographic resources.
• Rehabilitation of Trails. Pedestrian access to the base of Lower Yosemite Fall would be on either a rehabilitated western trail (the existing main access) or a better-defined and hardened eastern trail. These trails would connect to form a loop through the Lower Yosemite Fall area. Access to the base of Lower Yosemite Fall for visitors with mobility impairments would be via the redesigned and hardened eastern trail. Interpretive exhibits and seating would be added to both the western and eastern trails. An informal gathering/viewing area would be provided at the beginning of the western trail, and an informal viewing area would be located east of the shuttle bus stop. Stock (e.g., horse) use on trails would be managed as described in the Yosemite Valley Plan (see Vol. IA, page 2-65).
• Rehabilitation, Relocation, and Installation of Bridges. Five of the existing historic bridges along the eastern trail would be rehabilitated to allow wheelchair access throughout the area. Bridge #1 would be relocated to provide a better approach to a wheelchair-accessible boardwalk that would pass over the millrace feature within the historic Hutchings sawmill site. Construction and maintenance-related access to the Bridge #1 area would be via the existing maintenance thoroughfare through the nearby historic housing area. Materials staging would occur within existing impacted areas adjacent to the historic housing area. Both staging and access would be preceded by site-specific reconnaissance for cultural resources and natural resources so that there would be no potential impact to these resources. Bridge #2 would be rehabilitated as a boardwalk to allow creek hydrology to be restored. Bridge #3 would be rehabilitated to maintain access to the Muir plaque and Clark bench. Bridge #4 would be removed. Bridges #5 and #6 (closest to the shuttle bus stop) would be rehabilitated to help separate bicyclists from pedestrians, reduce congestion, improve circulation, and improve views. A seventh bridge (Bridge #7) would be constructed to replace a bridge formerly located east of Bridge #3 and complete a loop trail system. Yosemite Falls Bridge, the historic bridge across Yosemite Creek at the base of Lower Yosemite Fall, would be rehabilitated and the viewing platform enlarged.

The abutments for rehabilitated bridges would be moved out of the creek channels and located farther up on the banks. One new pier would be placed in the channel at Bridge #3, and two new piers would be placed in the channel at Bridge #6. Though a small portion of the channel would be blocked by new bridge piers, a larger portion of the channel would be enlarged and its hydrology would be restored as a result of removal of bridge abutments from the channel. The two piers at the Yosemite Falls Bridge would remain in the same location.

• View Corridor Maintenance. The Yosemite Valley Plan indicates the importance of maintaining historic views of Yosemite Falls related to the cultural landscape of Yosemite Valley, including the Lower Yosemite Fall area. Two historic view corridors through the Lower Yosemite Fall area (Western Trail and Hutchings) would be maintained by selective trimming of brush and branches and by selective cutting and removal of trees and vegetation within these view corridors. Removal of trees and vegetation to maintain the view corridors would be preceded by site-specific reconnaissance for cultural resources and natural resources, such as wetland vegetation, bat roost sites, and bird nest sites, so that there is no potential impact to those resources.
• Removal of Human-Built Rock-Rubble Pile. Removal of the rock-rubble pile downstream from the historic Yosemite Falls Bridge would be preceded by studies, thereby ensuring that this action would meet resource objectives.

Alternative 3 would involve the same actions described for Alternative 2, except for the location of the new restroom, the seating use of a portion of the existing parking area, an adjustment to the trail alignment near Bridge #1, a boardwalk at Bridge #2, and the disposition of the rock-rubble pile. Figure 2-3 is the site plan for Alternative 3. The Alternative 3 actions, all of which are unchanged from the Yosemite Valley Plan, are described below.

• Restroom Relocation. The restroom north of the existing parking area would be removed and a new restroom would be constructed east of Yosemite Creek and north of Northside Drive, adjacent to the future Lower Yosemite Fall shuttle bus stop.
• Parking Area Removal and Establishment of an Informal Seating Area. The existing parking area would be removed, and a portion of the area would be replaced with an informal seating area. However, a picnic area would not be installed in the area as it would under Alternative 2. The remainder of the area would be restored with locally native vegetation.
• New Shuttle Bus Stop. A new shuttle bus stop would be located on the north side of Northside Drive east of the Yosemite Creek Bridge.
• Interim Tour Bus Unloading, Loading, and Parking. To address removal of the tour bus loading/unloading and parking area from the Lower Yosemite Fall area, replacement loading/unloading and parking spaces would need to be provided for tour buses. Long-term tour bus loading/unloading would occur at the future new transit center in Yosemite Village. For an interim time period, a bus passenger loading and unloading zone would be provided along Northside Drive, near Cook’s Meadow, using the existing turnout west of Village Drive. Until day tour bus parking can be provided elsewhere, as called for in the Yosemite Valley Plan, for the interim day tour buses would park in an existing lane of Northside Drive, extending west of Camp 4. Day tour buses would park in the north (right) lane of the road until passengers are ready for pickup. When passengers are ready to load, buses would return to Northside Drive near Cook’s Meadow for passenger pickup. Interim parking for the few overnight tour buses would be provided in existing parking areas associated with nearby lodging facilities in Yosemite Valley.

• Trail Alignment, Including Relocation of the Eastern Trail Near Bridge #1. The trail between Bridges #1 and #2 would be rehabilitated and the trail northwest of Bridge #1 would be relocated to provide wheelchair accessibility to the area. The trail northwest of Bridge #1 would be placed on the millrace feature within the Hutchings sawmill site.
• Rehabilitation of Trails. Pedestrian access to the base of Lower Yosemite Fall would be on either a rehabilitated western trail (the existing main access) or a better-defined and hardened eastern trail. The western and eastern trails would form a loop through the area. Access to the base of Lower Yosemite Fall for visitors with mobility impairments would be via the redesigned and hardened eastern trail. Interpretive exhibits and seating would be added to both the western and eastern trails. An informal gathering/viewing area would be provided at the beginning of the western trail, and an informal viewing area would be located east of the shuttle bus stop. Stock (e.g., horse) use on trails would be managed as described in the Yosemite Valley Plan (see Vol. IA, page 2-65).
• Rehabilitation, Relocation, and Installation of Bridges. Five of the existing historic bridges along the eastern trail would be rehabilitated to allow wheelchair accessibility throughout the area. Bridge #1 would be relocated and an accessible trail would pass through the millrace feature within the historic Hutchings sawmill site. Bridge #2 would be rehabilitated. Bridge #3 would be rehabilitated to maintain access to the Muir plaque and Clark bench. Bridge #4 would be removed. Bridges #5 and #6 (closest to the shuttle bus stop) would be rehabilitated to help meet a variety of visitor experience needs and help separate bicyclists from pedestrians. A seventh bridge (Bridge #7) would be constructed to replace a bridge formerly located east of Bridge #3 to complete a loop trail system. Yosemite Falls Bridge, the bridge across Yosemite Creek at the base of Lower Yosemite Fall, would be rehabilitated and the viewing platform enlarged.

The abutments for the rehabilitated bridges would be moved out of the creek channels and located farther up on the banks. One new pier would be placed in the channel at Bridge #3, and two new piers would be placed in the channel at Bridge #6. Though a small portion of the channel would be blocked by new bridge piers, a larger portion of the channel would be enlarged and the hydrology would be restored as a result of removal of bridge abutments from the channel. The two piers at the Yosemite Falls Bridge would remain in the same location.

• View Corridor Maintenance. The Yosemite Valley Plan indicates the importance of maintaining Yosemite Falls historic views related to the cultural landscape of Yosemite Valley, including the Lower Yosemite Fall area. Two historic view corridors through the Lower Yosemite Fall area would be maintained by selective trimming of brush and branches and by selective cutting and removal of trees and vegetation within these view corridors.
• Removal of Human-Built Rock-Rubble Pile. The rock-rubble pile would be removed without further study, based on the information presented in the Yosemite Valley Plan.

Environmentally Preferable Alternative

The Council on Environmental Quality regulations implementing NEPA and the National Park Service NEPA guidelines require that "the alternative or alternatives which were considered to be environmentally preferable" be identified (Council on Environmental Quality [CEQ] Regulations, Section 1505.2). Environmentally preferable is defined as "the alternative that will promote the national environmental policy as expressed in NEPA’s Section 101. Ordinarily, this means the alternative that causes the least damage to the biological and physical environment; it also means the alternative that best protects, preserves, and enhances historic, cultural, and natural resources" (CEQ 1981).

Section 101 of NEPA states that

it is the continuing responsibility of the Federal Government to … (1) fulfill the responsibilities of each generation as trustee of the environment for succeeding generations; (2) assure for all Americans safe, healthful, productive, and aesthetically and culturally pleasing surroundings; (3) attain the widest range of beneficial uses of the environment without degradation, risk to 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 which supports diversity, and variety of individual choice; (5) achieve a balance between population and resource use which 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.

Alternative 2 is the environmentally preferable alternative for the Lower Yosemite Fall Project, based on its furtherance of the following national environmental policy goals.

Section 101 Requirement 1. "Fulfill the responsibilities of each generation as trustee of the environment for succeeding generations."

Conformance: Alternative 2 would best fulfill the responsibilities of each generation as trustees of the environment for succeeding generations by ensuring the protection of view corridors and restroom relocation away from culturally sensitive areas. Alternative 1, no action, would not protect the environment over time. Under Alternative 3, the view corridor would not be as protected and the new restroom location would interfere with a sensitive cultural area. Both Alternative 2 and Alternative 3 propose virtually identical trail alignments, which would be better defined than the existing trails, thereby reducing visitor trampling in sensitive areas.

Section 101 Requirement 2. "Assure for all Americans safe, healthful, productive, and aesthetically and culturally pleasing surroundings."

Conformance: Under Alternative 2, restroom relocation to an area that is not disruptive to sensitive cultural areas, as well as protection of the view corridor, would ensure that all Americans safe, healthful, productive, and aesthetically and culturally pleasing surroundings.

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

Conformance: Restroom relocation and protection of the view corridor under Alternative 2 would attain the widest range of beneficial uses of the environment, risks to health or safety, or undesirable and unintended consequences, namely retention of the inadequate restroom in its current location and condition represented by Alternative 1.

Section 101 Requirement 4. "Preserve important historic, cultural, and natural aspects of our national heritage, and maintain, wherever possible, an environment which supports diversity, and variety of individual choice."

Conformance: Alternative 2 would relocate the restroom to an area that is less disruptive to sensitive cultural resources compared to Alternatives 1 and 3. Alternative 2 would also better preserve the natural aspects by protecting the view corridor.

Section 101 Requirement 5. "Achieve a balance between population and resource use which will permit high standards of living and a wide sharing of life’s amenities."

Conformance: Under Alternatives 2 and 3, relocation of the restroom and location of a picnic area or seating area, respectively, would achieve a balance between population and resource use, which will permit high standards of living and a wide sharing of life’s amenities. Alternative 1 does not promote these standards.

Section 101 Requirement 6. "Enhance the quality of renewable resources and approach the maximum attainable recycling of depletable resources."

Conformance: Alternatives 2 and 3 would both achieve this requirement.

In conclusion, upon full consideration of the elements of Section 101 of NEPA, Alternative 2 represents the environmentally preferable alternative for the Lower Yosemite Fall area.

Actions Considered but Dismissed

For any project or activity within Yosemite Valley, a diverse range of actions could be considered. For the Lower Yosemite Fall area, a full range of alternatives was considered in the Yosemite Valley Plan. It is not the objective of this environmental assessment to revisit the range of alternatives in the Yosemite Valley Plan for the Lower Yosemite Fall area. Alternative actions have been eliminated from detailed study for any one or a combination of the following reasons:

• Does not implement the decisions of the Yosemite Valley Plan for the Lower Yosemite Fall area.
• Does not satisfy guidance criteria, meet project goals, or resolve park planning needs in Yosemite Valley.
• Less environmentally damaging options are available.
• Unacceptable environmental, cultural, or scenic impacts would be caused.
• Is not technically or economically feasible.

Those alternative actions considered but eliminated from detailed study are described below.

A few public comments received during the scoping period for this environmental assessment suggested that the National Park Service consider demolishing the existing Lower Yosemite Fall area restroom and construct a new restroom on the south side of Northside Drive across from the Lower Yosemite Fall area. This alternative action was considered but dismissed for the following reasons:

• Does not satisfy guidance criteria, meet project goals, or resolve park planning needs in Yosemite Valley – The restroom would not be centrally located and would not be within proximity to the shuttle bus stop and eastern trail.
  
• Unacceptable environmental, cultural, or scenic impacts would be caused – The restroom would interfere with the view of Yosemite Falls, especially for pedestrians approaching from Yosemite Lodge.
  
• Does not satisfy guidance criteria, meet project goals, or resolve park planning needs in Yosemite Valley – The restroom would not be located within proximity to the seating or picnic area.
  
• Does not satisfy guidance criteria, meet project goals, or resolve park planning needs in Yosemite Valley – The restroom would be within proximity to the existing Yosemite Lodge lobby restroom and would therefore not efficiently serve visitors to the Lower Yosemite Fall area.

The National Park Service considered maintaining the existing restroom and constructing an additional restroom at the southeast corner of the existing parking area. This alternative action was considered but dismissed for the following reasons:

• Does not satisfy guidance criteria, meet project goals, or resolve park planning needs in Yosemite Valley – Two buildings would not minimize or reduce the amount of built environment in the Lower Yosemite Fall area.
• Does not satisfy guidance criteria, meet project goals, or resolve park planning needs in Yosemite Valley – The existing restroom is inadequate. It is undersized for the number of users, unsightly, in need of major rehabilitation, and does not meet standards for accessibility under the Americans with Disabilities Act.
• Unacceptable environmental, cultural, or scenic impacts would be caused – The existing restroom would interfere with the view of Yosemite Falls.

During the public scoping process for this environmental assessment, it was suggested that the existing parking area be retained and modified to accommodate the shuttle bus stop. This alternative action was considered but dismissed for the following reasons:

• Does not implement the decisions of the Yosemite Valley Plan for the Lower Yosemite Fall area – The approved Yosemite Valley Plan called for removing the existing parking area.
• Does not implement the decisions of the Yosemite Valley Plan for the Lower Yosemite Fall area – As approved in the Yosemite Valley Plan, the current alignment of Northside Drive will be converted to a multi-use paved trail in the future and therefore not support vehicle access to the parking area.

During the public scoping process for this environmental assessment, it was suggested that the relocated restroom be constructed in the southwest corner or middle of the parking area. This alternative action was considered by the National Park Service but dismissed for the following reasons:

• Does not satisfy guidance criteria, meet project goals, or resolve park planning needs in Yosemite Valley – The restroom would be several hundred feet from the shuttle bus stop and eastern trail and would not support the goal of distributing visitors throughout the Lower Yosemite Fall area. Visitors would be drawn to the western trail.
• Unacceptable environmental, cultural, or scenic impacts would be caused – It would be difficult to locate the restroom without putting it in the western trail view corridor.

During the public scoping process for this environmental assessment, it was suggested that the new restroom be built in the center of the existing parking area and trees be planted around the new building. This alternative was considered and dismissed by the National Park Service for the following reasons:

• Does not satisfy guidance criteria, meet project goals, or resolve park planning needs in Yosemite Valley – The restroom would be several hundred feet from the shuttle bus stop and the eastern trail and would not support the goal of distributing visitors throughout the Lower Yosemite Fall area.
• Unacceptable environmental, cultural, or scenic impacts would be caused – The restroom would interfere with the view of Yosemite Falls, especially for pedestrians approaching from Yosemite Lodge.

Mitigation Measures Common to All Action Alternatives

The National Park Service places a strong emphasis on avoidance, minimization, and mitigation of impacts. This section summarizes mitigation measures suggested for each resource area that would largely offset potential impacts to these resource topics. No mitigation measures are proposed for Alternative 1.

To ensure that implementation of either of the action alternatives largely offsets impacts to natural and cultural resources and the quality of the visitor experience, the following Best Management Practices would be implemented, as appropriate, prior to, during, and/or after specific construction. (For the purposes of this discussion, construction includes major repair and/or rehabilitation, demolition, deconstruction, reconstruction, restoration, etc.) Specific tasks would include, but not be limited to, the following:

• Implement a compliance-monitoring program in order to stay within the parameters of National Environmental Policy Act and National Historic Preservation Act compliance documents, U.S. Army Corps of Engineers Section 404 permits, etc. The compliance-monitoring program would oversee these mitigation measures and would include reporting protocols.
• Implement a natural resource protection program. Standard measures could include construction scheduling, biological monitoring, erosion and sediment control, use of fencing or other means to protect sensitive resources adjacent to construction, removal of all food-related items or rubbish to bear-proof containers, topsoil salvage, and revegetation. The program could include specific construction monitoring by resource specialists as well as treatment and reporting procedures.
• Implement a cultural resource protection program. Standard measures could include consideration of adaptive reuse, relocation, and salvage of historic building materials; archeological monitoring during ground-disturbing activities (in keeping with the 1999 Programmatic Agreement); use of fencing or other means to protect sensitive resources adjacent to construction; and preparation of a discovery plan to handle unanticipated exposure of buried human remains or previously unknown cultural resources. The program could include specific construction monitoring by resource specialists and culturally associated Indian people, as well as treatment and reporting procedures.
• Implement a traffic control plan, as warranted. Standard measures could include strategies to maintain safe and efficient traffic flow during the construction period.
• Implement a dust abatement program. Standard dust abatement measures could include the following elements: water or otherwise stabilize soils, cover haul trucks, employ speed limits on unpaved roads, minimize the clearing of vegetation, and revegetate post-construction.
• Implement standard noise abatement measures during construction. Standard noise abatement measures could include the following elements: a schedule that minimizes impacts to adjacent noise-sensitive uses, use of the best-available noise control techniques wherever feasible, use of hydraulically or electrically powered impact tools when feasible, and location of stationary noise sources as far from sensitive uses as possible.
• Implement a noxious weed abatement program. Standard measures could include the following elements: ensure construction-related equipment arrives on site free of mud or seed-bearing material, certify all seeds and straw material as weed-free, identify areas of noxious weeds before construction, treat noxious weeds or noxious weed topsoil prior to construction (e.g., topsoil segregation, storage, or sterilization), and revegetate with appropriate native species.
• Implement a spill prevention and pollution control program for hazardous materials. Standard measures could include hazardous materials storage and handling procedures; spill containment, cleanup, and reporting procedures; and limitation of refueling and other hazardous activities to upland/nonsensitive sites.
• Implement measures to reduce adverse effects of construction on visitor safety and experience.
• Implement a notification program. Standard measures could include notification of sensitive receptors, utilities, and emergency response units prior to construction activities.
• Implement an interpretation and education program. Continue directional signs and education programs to promote understanding among park visitors.
• Use silt fences, sedimentation basins, etc., in construction areas to reduce erosion, surface scouring, and discharge to water bodies.
• Develop revegetation plans for the disturbed area and require the use of native species. Revegetation plans would specify seed/plant source, seed/plant mixes, soil preparation, etc. Salvaged vegetation would be used to the extent possible.
• Delineate wetlands and apply protection measures during construction. Wetlands would be delineated by qualified National Park Service staff or certified wetland specialists and clearly marked prior to construction work. Construction activities would be performed in a cautious manner to prevent damage caused by equipment, erosion, siltation, etc.
• Develop architectural character guidelines for new construction in or near historic districts. All new development would be designed to be compatible with historic resources in terms of scale, massing, materials, architectural elements, and orientation with designated historic sites, structures, or districts.

Construction of the Lower Yosemite Fall Project would begin in the spring of 2002 and continue through the fall of 2004. Construction activities would occur year round, weather permitting. Construction sites would be fenced off and/or flagged to maintain visitor safety during both work and non-work hours.

Equipment that would likely be used for project activities would include but not be limited to the following: crane, front end loader, jackhammer, pneumatic hammer, dump truck (10-cubic-yard capacity), paving machine, trencher, scraper, backhoe, bobcat, and forklift.

Although most of the material within the Lower Yosemite Fall area would be reused elsewhere on site, asphalt and demolition debris would be moved off site. Many materials necessary for the construction of a new restroom and for bridge and trail construction would be brought in from outside the park. Trucks are expected to travel to and from the construction site, bringing in or removing building/asphalt material. The number of truck trips anticipated for construction is not considered a significant change from existing conditions for the limited time construction would be underway. For activities occurring adjacent to Yosemite Lodge, construction timing would be limited to minimize impacts to lodge visitors. For heavy construction involving loud noises, construction activity may start no earlier than 9 a.m.

An adequate portion of the existing parking area would be made available to the contractor for construction staging. The National Park Service would ensure that interim parking is available for Lower Yosemite Fall area visitors during project construction.

When construction is under way, the tour buses that currently park at the lot and unload passengers would be displaced. The National Park Service would offset this temporary loss and inconvenience through the following strategies:

• Interim tour bus loading and unloading in an area east of the new shuttle bus stop.
• Interim parking of the tour buses along Northside Drive, west of Camp 4 and Yosemite Lodge.

Construction activities would be phased so that visitors’ recreational use of the area would not be overly restricted. Phasing would occur over the course of approximately 2½ years; breaks may be taken during bad weather. Construction would be phased so that only one trail would be reconstructed at any given time. The seating/picnic area located at the southern portion of the parking area would be among the last project elements constructed. During this last phase of construction, the parking area would be removed in parts so that it would remain in use as a construction staging area.

The following measures would largely offset potential impacts to identified wetlands in the Lower Yosemite Fall area.

• All facilities would be sited to avoid wetlands or comply with Executive Order 11990 (Protection of Wetlands), the Clean Water Act, and Director’s Order 77-1 (Wetland Protection; see Appendix A for further discussion).
• Increased caution and protective fencing would be used to protect wetlands from damage caused by construction equipment, erosion, siltation, and other ground-disturbing activities, notably those wetlands near Bridges #3, #5, and #6 and the Yosemite Falls Bridge.
• Design of all bridges in the Lower Yosemite Fall area would include removal of abutments from the wetlands and providing longer spans to avoid wetlands below the bridges; these longer spans would be designed to avoid direct impacts to delineated wetlands.
• Construction materials would be prevented from escaping work areas, especially near streams or natural drainages, and impacting downgradient wetlands.
• Every effort would be made to avoid adversely impacting wetlands during view corridor maintenance activities.
• Removal of trees and vegetation to maintain the view corridors would be preceded by site-specific reconnaissance for natural resources, such as wetland vegetation, bat roost sites, and bird nest sites, to avoid potential impacts to those resources.

Soil erosion and contamination result in impacts to air and water quality as well as to habitats for plant and wildlife species. The following mitigation efforts would focus on minimizing or largely offsetting these impacts.

• Use approved siltation and sediment control devices in construction areas to reduce erosion and surface scouring.
• Use approved siltation and sediment control devices appropriate to the situation in grading areas to capture soil erosion before discharge to braided stream channels.
• Use water bars in temporary access roads to control and reduce surface scouring.
• Use dust abatement measures (water applications) to reduce airborne soil erosion, including setting speed limits for construction vehicles in unpaved areas and hauling cover soil and debris away in trucks.

Measures would be taken to largely offset the potential for public exposure to noxious materials or contaminants that may be present during construction near the Lower Yosemite Fall area. Potential exposure would be controlled by providing established and maintained walkways and bridges across the site, covering walking paths with clean soil and asphalt, and providing barrier fencing along trails.

The following mitigation measures would be applied to largely offset potential impacts to water resources.

• Take measures to control erosion, sedimentation, and compaction, and thereby reduce water pollution.
• Remove hazardous waste materials generated during implementation of the project from the project site immediately.
• Place construction debris in refuse containers at least daily.
• Dispose of refuse at least weekly. No refuse would be burned or buried inside the park.
• To the extent possible, schedule the use of mechanical equipment during periods of low precipitation and low groundwater levels to reduce the risk of accidental hydrocarbon leaks or spills. When mechanical equipment is necessary outside of low precipitation periods, use National Park Service–approved methods to protect soil and water from contaminants.
• Dispose of volatile wastes and oils in approved containers for removal from construction sites to avoid contamination of soils, drainages, and watercourses.
• Inspect equipment for hydraulic and oil leaks prior to use on construction sites, and implement inspection schedules to prevent contamination of soil and water.
• Keep absorbent pads, booms, and other materials on site during projects that use heavy equipment to contain oil, hydraulic fluid, solvents, and hazardous material spills.
• Integrate stormwater pollution controls, in accordance with National Pollution Discharge Elimination requirements that concentrate runoff shall be integrated into design, construction, and operation of the new restroom, and paved trails.

Actions occurring within the Merced River floodplain would be subject to the provisions of the National Park Service Floodplain Management Guideline 1993 (Special Directive 93-4; Director’s Order NPS 77; see Appendix A for further discussion) and Executive Order 11988 (Protection of Floodplains). The following mitigation measures would be applied to largely offset potential impacts to facilities within the floodplain:

• An emergency preparedness plan would be developed for any facilities within the floodplain. The National Park Service would continue to maintain and update a flood evacuation plan. The plan details responsibilities of individual park employees for advanced preparedness measures; removing or securing park property, records, and utility systems; monitoring communication; and conducting salvage operations.
• The site design or modifications would minimize harm to floodplain values and risks to life and property. The design of all new structures would incorporate methods for minimizing flood damage as contained in the National Flood Insurance Program Floodplain Management Criteria for Flood-Prone Areas (CFR 44:60.3) and in accordance with any local, county, or state requirements for flood-prone areas.
• The design for the impermeable areas would ensure natural resources are not damaged by pavement runoff from normal rainfall events.

Mitigation actions would occur prior to, during, and/or after construction to largely offset immediate and long-term impacts to vegetation. Mitigation would include the following:

• Develop revegetation and ecological restoration plans for disturbed areas, using native species from the same gene pool. Revegetation plans would specify soil preparation, native seed/plant mixes, seed/plant sources, and mulching for all areas disturbed by construction activities.
• Develop and implement a monitoring plan to ensure successful revegetation, maintain plantings, and replace unsuccessful plant materials.
• Salvage vegetation to the extent possible for use in revegetating disturbed areas.
• Enforce construction specifications regarding soil salvage and reuse, trenching, plant protection, and finished grading.
• Site buildings, bridges, and trails to minimize impacts to vegetation. Avoid large trees and hardwood and riparian species, where possible.
• Select base course and fill materials for compatibility with native granitic soils to minimize risk of introducing non-native plant seeds. Monitor areas where fill is imported from outside the park, and eradicate non-native plants. Apply standard techniques to prevent non-native plant encroachment.
• Develop monitoring and mitigation plans for managing non-native plants within and immediately surrounding construction and developed areas.
• Confine all construction operations to specified project work limits. Install temporary barriers to protect natural surroundings (including trees, plants, and root zones) from damage. Repair or replace damaged trees and plants, and avoid fastening ropes, cables, or fences to trees.
• Install fencing to minimize use of highly sensitive sites such as creek edges and wetlands, and install signs as needed to direct use to more appropriate areas. Placement of fencing and signs would be developed in consultation with National Park Service cultural resource staff.
• Use native or seed-free mulch to minimize surface erosion and introduction of non- native plants.
• In site design, define trails and boundaries of development to confine human use and reduce radiating impacts.

Mitigation actions would occur prior to, during, and after construction to minimize immediate and long-term impacts to wildlife. Many of the measures listed above for vegetation would also benefit wildlife by helping to preserve habitat. Actions to largely offset impacts specific to wildlife would include the following:

• Prior to construction, evaluate habitat for species likely to occur and take steps to minimize impact on those species determined to be especially vulnerable.
• Limit the effects of light and noise on adjacent habitat through controls on construction equipment, and through site design of facilities, to limit long-term effects of resulting development. Limit noise from transit vehicles through application of best available low noise technologies and use of operating strategies.
• Install fencing and signs to direct visitors away from sensitive habitats.
• Provide adequate education and enforcement to limit visitor activities that are destructive to wildlife and habitats.
• When possible, schedule any disruptive construction activities to occur when effects on wildlife would be minimal (for example, after birds nesting season and when bats are neither hibernating nor have young).
• Preserve, where possible, natural features with obvious high value to wildlife, such as tree snags.
• Maintain routes of escape from excavated pits and trenches for animals that might fall in. Cover post holes and other narrow pits with boards. During construction, maintain vigilance for animals caught in excavations and take appropriate actions to free them.
• Provide safeguards to limit the chance of pollution spills, both during construction and during subsequent use of completed facilities. This is especially important where activities are near aquatic or wetland habitats.
• Prior to tree-thinning activities in view corridors, National Park Service biologists would screen the area for bat roosts, nesting birds, snags, and other features that are important wildlife habitat.

• Require construction personnel to adhere to park regulations concerning food storage and refuse management.
• Provide bear-proof containers in the seating/picnic area.
• Provide adequate cleaning of areas and garbage pickup to limit wildlife access to human food.

The U.S. Fish and Wildlife Service is responsible for administering conservation and recovery measures to protect federally listed species, as directed in the Endangered Species Act of 1973. The U.S. Fish and Wildlife Service has prescribed conservation measures specific to the Yosemite Valley Plan (see Vol. II, Appendix L) as part of its Biological Opinion. The Biological Opinion contains Terms and Conditions that are non-discretionary. In addition, the National Park Service has developed mitigation measures for all special-status species. These mitigation measures can be found in the Biological Assessment completed for the Yosemite Valley Plan (see Vol. II, Appendices A and K). In addition, the following measure would be applied to largely offset potential impacts to special-status wildlife species.

• Survey view corridors (before selective thinning takes place) to identify any likely bat roosting trees and snags. Retain identified roosting trees and snags to serve as habitat for special-status bats.

The National Park Service would seek to perpetuate the best possible air quality by aggressively promoting and pursuing measures to preserve, protect, and enhance air resources. Moreover, actions are subject to the provisions of the Clean Air Act and the forthcoming State of California’s State Implementation Plan. The following mitigation measures would be applied to largely offset potential air quality impacts in the Lower Yosemite Fall area.

• Dispose of refuse at least weekly. No refuse would be burned inside the park.
  
• Employ dust abatement measures.

To largely offset the effects of project construction noise, the following measures would be applied.

• Implement standard noise abatement measures during park operations. Standard noise abatement measures could include the following elements: a schedule that minimizes impacts to adjacent noise-sensitive uses, use of best available noise control techniques wherever feasible, use of hydraulically or electrically powered impact tools when feasible, and location of stationary noise sources as far from sensitive uses as possible.
• Site and design facilities to minimize objectionable noise.

The National Park Service has developed a Programmatic Agreement in consultation with the California State Historic Preservation Officer, the Advisory Council on Historic Preservation, culturally associated American Indian tribes, and the public. This agreement stipulates a process for the treatment of historic properties, including identification, evaluation, and, if necessary, mitigation of adverse effects. Standard mitigation measures may be used in situations where an undertaking would adversely affect a historic property. These include documentation, interpretation, materials salvage, and National Register re-evaluation.

Construction monitoring would be performed in keeping with the Archeological Synthesis and Research Design, Yosemite National Park, California (Hull and Moratto 1999), and as specified in the 1999 Programmatic Agreement (NPS 1999a). The project would strive to avoid intact deposits through careful project design. If intact deposits cannot be avoided, all data recovery to retrieve important information would be conducted in accordance with the Yosemite Programmatic Agreement. Where previously unknown American Indian burials and archeological sites are discovered during construction, provisions outlined in the Native American Graves Protection and Repatriation Act and its implementing regulations would also be followed.

Through existing agreements and ongoing consultation with culturally associated American Indian tribes, access to and use of special resources in Yosemite Valley would continue. To reduce potential impacts to ethnographic sites, designs would be developed to prevent visitors from wandering off designated trails. Additional measures to largely offset potential impacts to cultural resources are listed below.

• The park would continue to consult with tribes throughout the site-specific design process and project implementation to avoid or mitigate damage to ethnographic resources (e.g., trails would be better defined and barriers would be created to minimize trampling of ethnographic resources).
• Impacts to ethnographic resources would be mitigated through actions developed in consultation with culturally associated American Indian tribes.
• A parkwide gathering plan would be developed in consultation with American Indian people, as specified in the Programmatic Agreement. The plan could include strategies for identifying and continuing to help provide access to gathering areas, continuing to provide access to traditional use or spiritual areas, and screening new development from traditional use areas.
• Impacts would be mitigated by continuing to provide access to traditional and spiritual locations, and where appropriate screening new development from traditional use areas.
• Removal of trees and vegetation to maintain the view corridors would be preceded by site-specific reconnaissance for cultural resources to avoid potential impacts to those resources.
• Interim bus parking would not be adjacent to the Indian Cultural Center when it is constructed.
• In order to discourage visitor trampling of identified ethnographic resources, barriers and signs would be placed along the trails from Bridge #6 to the shuttle bus stop and from Bridge #6 to the informal viewing area in the Hutchings view corridor.
• New bridges would be designed in keeping with design criteria guidelines taken from the bridges they would replace so that they would fit within and be sensitive to the cultural landscape.

Mitigation measures for scenic resources are designed to minimize visual intrusions. Many of the mitigation measures identified in the Vegetation section, above, would assist to largely offset potential scenic impacts. These include:

• Minimize development footprints.
• Choose building materials that are visually compatible or do not compete with the landscape.
• Provide vegetative screening, where applicable.

The following specific mitigation measures would be implemented to largely offset potential impacts to scenic resources related to view corridors shown on figure 2-2:

• Consult with the National Park Service vegetation ecologist during the planning and implementation phases of revegetation activity. Base revegetation prescriptions on resource objectives for the site and a site-specific analysis of the plant community, soils, and cultural resources. Consult with the landscape architect or historical architect for protection of cultural landscapes.
• Use selective trimming and cutting techniques when establishing and maintaining vistas. Some vegetation cover would be left on the ground while a viewing area is opened up through standing trees. Develop the appearance of a natural setting by leaving trees of different size classes. Trim standing trees so that low limbs do not block scenic view corridors and in a manner that no cutting pattern is evident.
• Dispose of wood in accordance with strategies defined in the Yosemite Valley Plan. Whenever possible, the preferred method is decomposition on site to allow cut vegetation to cycle through the ecosystem. Fire hazard fuels must be considered in certain plant communities where fire has not been allowed.
• Provide interpretive materials and programs to communicate the park’s scenic management policies and procedures for establishing, restoring and maintaining scenic vista points or areas and, more importantly, for interpreting the scene at hand and its historical or natural significance.
• Wherever possible, revegetation efforts in natural zones would use seeds, cuttings, or transplants representing species and gene pools native to the ecological area of the park in which the revegetation project is occurring.
• Avoid impacts to cultural resources during management of the vistas. If avoidance is not feasible or prudent, the National Park Service would undertake separate compliance with NEPA and the National Historic Preservation Act.
• When approval is granted for removal of trees to maintain view corridors, Best Management Practices required to protect park values may include, but not be limited to, monitoring of operations on or near the site by an archeologist, complete site avoidance, the establishment of an equipment exclusion zone, directional falling of adjacent trees away from the site area, use of rubber-tired equipment only, or restrictions on piling and burning of slash on site. These protection measures are generally used in combination with one another (Foster 1995).

The following mitigation strategies would be implemented to largely offset potential impacts to visitor experience at the Lower Yosemite Fall area.

• Develop an exhibit plan for the Lower Yosemite Fall Project to redirect exhibits from roadside to trailside interpretation.
• Increase ranger programs for the Lower Yosemite Fall Project to provide more interpretive opportunities.
• Continue to develop standards and indicators to improve resource protection and visitor experience.
• Limit the interim day tour bus parking adjacent to Camp 4 to the time of day that would impact campers the least.

The following mitigation measures would be implemented to largely offset potential impacts to park utilities.

• Utility locations would be verified through field survey (potholing) and use of the Underground Service Alert services prior to the start of construction.
• The National Park Service would observe California Department of Health Services standards that require (1) a 10-foot horizontal separation between parallel sewer and water mains; (2) 1-foot vertical separation between perpendicular water and sewer line crossings (in the event that separation requirements cannot be maintained, California Department of Health Services would obtain variance through provisions of water main encasement, or other means deemed suitable by California Department of Health Services); and (3) encasement of water mains in protective sleeves where a new sewer force main (pipeline) crosses under or over an existing sewer main.
• The National Park Service would observe guidelines specified in the National Plumbing Code, International Plumbing Code, or Building Officials and Code Administration (BOCA) National Plumbing Code regarding utilities installation and or abandonment of pipelines.

Utility services that are unexpectedly interrupted because of construction activities would be reconnected promptly. In addition, all phases of construction that may result in a disruption of utility service would require advance notification to all residents, concession activities, and other National Park Service visitor activities.

The following transportation mitigation measures would be implemented to largely offset potential impacts to park resources and operations and facilities.

• Integrate stormwater pollution control measures into parking area design and construction.
• Implement a traffic management program, as warranted. Standard measures could include strategies to maintain safe and efficient traffic flow during the construction period.
• Install appropriate traffic signs, and stripe both the interim day tour bus loading/unloading area and parking spaces.
• Restrict buses from idling at all times (whether loading or unloading).
• Staff both the interim bus loading/unloading area and the interim bus parking area to ensure that bus operations do not delay traffic. Staff would ensure that (1) the interim bus loading area is always available for loading and unloading passengers, (2) several buses do not pick up passengers simultaneously or when space is not available, and (3) buses do not idle while parked or while waiting for passengers to load and unload.

In April 1999, the United States Department of the Interior entered into a formal Memorandum of Understanding with the United States Department of Energy to promote the use of energy-efficient and renewable energy technologies and practices in national parks. While the Memorandum of Understanding does not mandate specific energy-efficient and renewable energy technologies, it does provide a framework to promote their implementation and use. The Memorandum of Understanding would guide the selection of energy efficient technologies for the Lower Yosemite Fall Project and would largely offset potential impacts to energy consumption.

Summary of Environmental Consequences

Table 2-1 summarizes and compares the potential environmental consequences associated with each alternative. Potential environmental consequences are analyzed in more detail in Chapter 4.

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