| Table of Contents | Alternative 3 | Alternative 4 | Alternative 5 | Commitments of Resources | Uses/Productivity |
| Short-Long Term | Chapter 5 | Chapter 6 | Bibliography | Glossary | Acronyms/Abbreviations | Index |
| Part 1 | Part 2 | Part 3 | Part 4 |

The analysis of potential impacts from actions implemented under Alternative 4, Taft Toe and Out-of-Valley Parking (El Portal, Badger Pass, and South Landing), are presented in this section.

This section analyzes impacts to water resources: hydrology, including floodplain values, and water quality. Impacts to water resources are described by area (i.e., Yosemite Valley, El Portal, Wawona, and out-of-Valley parking locations) and are characterized as long-term alterations or restoration of hydrologic processes (e.g., water flow and flood regime) or water quality (e.g., turbidity, and non-point source pollution from vehicles or recreational use).

YOSEMITE VALLEY HYDROLOGY

Actions to implement the River Protection Overlay include the removal of development within 150 feet of the river. These actions would restore the river to more natural geomorphologic conditions through restoration of stream banks (i.e., streambank stability) and the 100-year floodplain. The River Protection Overlay would allow natural processes to prevail in the river and floodplain and minimize the alterations of the floodplain due to existing and future facilities. Further, removal of development from the River Protection Overlay would potentially reduce visitor degradation of stream banks and the river channel by concentrating visitor use away from the river. Examples of these areas include Housekeeping Camp, certain meadow roads and turnouts, and riverside campgrounds. Removal of facilities from the River Protection Overlay would allow natural floodplain alterations and lateral movement of the river channel (i.e., meandering), and increase opportunities for restoration of riparian vegetation, which would reduce unnatural erosion and deposition. Ultimately, the implementation of the River Protection Overlay would result in a regional, long-term, major, beneficial impact on hydrology and floodplain values.

Camp 6 would be restored between Northside Drive and the Merced River, allowing for restoration of some of the oxbows and cut-off channels that once existed in the area. Changes to the existing river dynamics through restoration of oxbows and braided streams could, over time, become more locally pronounced and eventually contribute to restoration of natural stream flow conditions downstream of the area. Restoration actions at Camp 6 would result in localized, long-term, major, and beneficial impacts on hydrology and the floodplain values.

The construction of a parking facility and transit center at Taft Toe would alter surface hydrology by the removal of vegetation and replacement with an impervious surface. In addition, riverbank instability (soils compaction and vegetation loss) could be the result of radiating impacts associated with the increased concentration of visitors. As a result of these alterations to hydrology, there would be a localized, minor, long-term, and adverse impact on hydrology.

The parking facility and transit center at Taft Toe would be constructed largely outside of the 100-year floodplain, but the concentration of visitors would have radiating impacts to the river and its hydrologic processes. This would be a long-term, minor, and adverse impact.

The construction of a picnic area at the location of the former Superintendent’s House (Residence 1) would have a long-term, minor, and adverse impact on hydrology due to radiating impacts of increased visitor use to a sensitive stretch of riverbank.

At Yosemite Lodge, Northside Drive would be rerouted to the edge of the 100-year floodplain and parking would be reconfigured, but would remain in the 100-year floodplain. This would result in a long-term, minor, adverse impact on hydrology because flood flow would be altered.

The removal of three structures at Ahwahnee Row that are located in the 100-year floodplain would have a localized, long-term, minor, beneficial impact on floodplain values by removing impediments to flood flow (particularly pooling in this area).

Restoration areas include the portions of Yosemite Lodge (including motel units that impede flood flow and the former cabins area), Upper and Lower River Campgrounds, North Pines Campground, and roads from Stoneman and Ahwahnee Meadows that are in the 100-year floodplains. Removal of these facilities and restoration would restore the hydrologic process of flooding, and would be a long-term, moderate, beneficial impact on hydrology.

The presence of a bridge as a fixed structure within a river course can cause alterations in river flow and result in localized morphologic changes to the beds and banks of the river. Morphologic changes attributable to bridge placement, and that are most readily observable, would include scour holes on the downstream side of the abutment, formation of deposition bars downstream of the scour holes, bank instability, unnatural erosion and deposition, changes in flow velocity, and localized channel widening. Removal of these fixed structures would provide for restoration of natural erosion and deposition process; allow the river to meander and naturally alter course; and reduce flooding potential by removing flow impediments. The impacts of bridge removal would be noticeable as the scour holes and downstream deposition bars caused by their in-river abutments diminish and the riverbank is reestablished by natural flow patterns. Bridge removal would continue to improve natural river flow dynamics along extended reaches of the river, and the impacts would be observable for years to come.

Sugar Pine Bridge constricts the river severely, largely because this bend of the river immediately downstream of the Tenaya Creek confluence has always been dynamic. The approach road that connects Ahwahnee Bridge to Sugar Pine Bridge eliminated the numerous small cutoff channels that existed prior to construction in 1929. The loss of the numerous small cutoff channels, combined with the constriction of the river by Sugar Pine Bridge, has forced the creation of a single large cutoff channel immediately adjacent and parallel to the approach road. Removal of Sugar Pine Bridge and the approach road and restoration of the riverbank (vegetation, bank slope, channel width) would be a localized, long-term, major, beneficial impact on the Merced River’s hydrology, by reducing unnatural erosion and scouring, reducing unnatural deposition downstream of the bridge, and allowing the river to meander.

Stoneman Bridge constricts the river severely, causing increased velocities during high flow and the resultant formation of a downstream scour pool and mid-channel bar. The presence of the bar has caused erosion rates to increase unnaturally along the left (southern) bank. The constricted channel width has also had upstream impacts, with flood waters backed up behind the bridge causing erosion on both banks. Removal of Stoneman Bridge and restoration of the riverbank (vegetation, bank slope, and channel width) would be a localized, long-term, major, beneficial impact on the Merced River’s hydrology, by reducing scouring and unnatural erosion both upstream and downstream of the bridge, by reducing unnatural deposition downstream of the bridge, and by allowing the river to meander.

Housekeeping Bridge moderately constricts the river and has three center piers in the river channel that cause increased velocities, formation of three scour holes at the bridge, and downstream erosion (particularly at the left bank). Removal of Housekeeping Bridge and restoration of the riverbank (vegetation, bank slope, and channel width) would be a localized, long-term, moderate, beneficial impact on the Merced River’s hydrology by reducing scouring and unnatural erosion.

Superintendent’s Bridge minimally constricts the river, but has center piers in the river channel that interfere with transport of large, woody debris. Removal of Superintendent’s Bridge would be a localized, long-term, minor, beneficial impact on the Merced River’s hydrology by allowing free movement of large, woody debris.

Removal of these four bridges would also be a localized, long-term, major, and beneficial impact on floodplain values by removing impediments to flood flow, particularly large flood events such as the January 1997 flood event. Local, short-term, minor, adverse impacts to hydrology may occur during bridge removal due to construction activities in the main channel.

At Yosemite Creek, the human built rock rubble pile blocking the western channel would be removed, as would the pedestrian bridge and its abutments immediately upstream of the Yosemite Creek Bridge (vehicle). Removal of these impediments would restore hydrologic processes such as annual spring runoff, particularly restoration of flow to the western channel of the braided stream network, and would be a long-term, minor, beneficial impact on hydrology. Local, short-term, negligible impacts to hydrology may occur during removal due to construction activities in the western channel during construction.

A new vehicle bridge would be constructed downstream of the existing Yosemite Creek Bridge. The abutments of the new bridge would be outside of ordinary high water and would minimally impact hydrologic processes. This would result in a long-term, minor, adverse impact on hydrology. Local, short-term, minor, adverse impacts on hydrology may occur during bridge construction due to construction activities in the main channel.

The possible reconstruction of Swinging Bridge would have long-term, localized, minor, beneficial impacts on the Merced River’s hydrology, because the bridge abutments would be removed from the riverbank (although some piers would remain in the river). Local, short-term, minor, adverse impacts on hydrology would occur during reconstruction due to construction activities in the main river channel.

Cascades Diversion Dam was constructed in 1917 to impound water for the intake structure that diverted river flows to a downstream powerhouse. Use of the powerhouse to generate hydroelectric power was discontinued in 1985, as was the diversion of river flows. The dam is located at a natural breakpoint in the channel gradients: upstream of the dam the gradient is .01 feet/feet; downstream of the dam the gradient is .06 feet/feet. The pool and backwater created by the dam extend upstream from the dam about 550 feet. The dam is in danger of failure: outside of spring snowmelt runoff and rain-on-snow winter floods, water flows under the dam instead of through the spillway or over the dam. Failure of the dam would result in unmitigated release of the sediment trapped behind the dam, and materials that comprise the dam. Removal of the dam would have a localized, long-term, major, beneficial impact on the Merced River’s hydrology by preventing the adverse impacts of dam failure and restoring the free-flowing condition of the river: sediment transport would be unimpeded; natural low-water and flood flow would be restored; and riparian vegetation currently displaced by the pool and backwater would be restored on the riverbanks.

Removal of Cascades Diversion Dam would also be a localized, long-term, major, beneficial impact on floodplain values by removing a substantial impediment to flood flow: both annual spring runoff, and large flood events such as the January 1997 flood event.

Reconstruction of the El Portal Road between the Cascades Diversion Dam and Pohono Bridge could have a beneficial impact on hydrology if the footprint of the existing bank stabilization in the river is reduced, or could have an adverse impact to hydrology if the footprint of the existing bank stabilization in the river is increased. Additional environmental compliance, including a Wild and Scenic River Act Section 7 determination, would be necessary before this segment of road can be reconstructed.

YOSEMITE VALLEY WATER QUALITY

Actions to implement the River Protection Overlay would remove sources of pollutants and reduce erosion and sedimentation by removing facilities and limiting activities associated with facility use and maintenance. These activities include vehicle maintenance, roadwork, and construction projects. Additionally, the possible realignment or relocation of roads, trails, and visitor facilities could reduce the introduction of refuse and bacteria by visitors. The removal of the concessioner stable and the Swinging Bridge Picnic Area and restoration to natural conditions would reduce a source of nutrients, coliform, turbidity, and other water pollutants from the Merced River. Actions to implement the River Protection Overlay would limit or remove development that is immediately adjacent to the river, thereby providing a buffer to impede the migration of non-point source pollutants from discharge areas to the Merced River.

The removal of parking spaces from Curry Orchard, Yosemite Falls, the concessioner stable, Camp 6, and roadside areas throughout the Yosemite Valley would substantially reduce the potential sources of non-point source pollution that are inherent in areas with heavy, concentrated vehicular use. Vehicles can release pollutants onto pavement, including asbestos, heavy metals, petroleum-based products, and other chemicals such as ethylene glycol. Some fraction of these chemicals can be carried by surface-water runoff to streams, and eventually the Merced River. A formalized parking facility would be established at Taft Toe, with stormwater pollution controls incorporated into its design (possible treatment methods include sand filters, underground water collection and treatment tanks, or oil/water separators). The construction of a parking facility at Taft Toe would introduce a new non-point pollution source to the west Valley, although stormwater pollution controls would be incorporated into the design of the facility to minimize the pollution. This facility would have a localized, long-term, minor, adverse impact on water quality. Replacing the existing parking areas listed above with a formalized parking facility at Taft Toe would improve water quality by reducing non-point source pollution from stormwater runoff from large, paved surfaces, resulting in a regional, long-term, moderate, and beneficial impact on water quality.

The increased use of shuttle buses would reduce the number of vehicle miles traveled in the Valley, and allow the removal of some roads (e.g., roads through Stoneman and Ahwahnee Meadows). This would have long-term, minor, beneficial impacts on water quality by reducing non-point source pollution.

EL PORTAL HYDROLOGY

As a result of a U.S. Army Corps of Engineers study (1998), the flood protection levee (hereafter, "levee") in the Hennessey’s Ranch area would need to be raised and extended in order to protect employee housing, the impacts of which would be two-fold.

First, the levee would limit and possibly redirect natural river flow through a localized reach of the river during a 100-year flood event, reducing channel width and increasing flows or eddies depending on floodwater velocity and height. The levee is above the normal high water line and would not affect the river flow during normal spring runoff periods. Increasing the length and height of the levee would be a localized, long-term, minor, adverse impact on the river’s hydrology because this reach of river has low susceptibility to bank scour, erosion, and slope instability.

Secondly, any structure intended to prevent flooding has the potential to limit the natural formation and function of that river’s floodplain. Most of the Merced River in El Portal is confined within a bedrock gorge channel, and the floodplain is narrow due to the river gradient and resistant bedrock. Consequently, the majority of the floodplain is more resilient and less susceptible to adverse impacts of altered river flow. The area at Hennessey’s Ranch is one of the few flat, alluvial floodplain sections adjacent to the Merced River at El Portal. The alluviated area was formed through years of river sediment deposition. After construction of the existing flood protection levee, this area was isolated from further sediment deposition because the levee height prevented inundation by large flood flow such as the January 1997 flood event, which was the largest flood event in the 80+ years of stream gauge data at the Pohono gauging station. When compared to the impact of the existing flood protection levee, increasing the length and height of the levee would be a localized, long-term, minor, adverse impact on floodplain values because only flood flow greater than the January 1997 flood event would be affected.

Removal of housing from the River Protection Overlay at Hennessey’s Ranch and restoration of the area would have long-term, minor, beneficial impacts on hydrology by restoring river-related communities and hydrologic processes.

Construction of new housing in the 100-year floodplain but outside of the River Protection Overlay would require the modification of the levee (discussed above), and would result in radiating impacts to the riverbank due to increased employees living in the area. These radiating impacts would have a long-term, minor, adverse impact.

Two pedestrian bridges would be constructed in the vicinity of Hennessey’s Ranch. The bridges and their abutments would be designed to not interfere with the free-flowing condition of the river, and the banks of this river reach are relatively stable and resilient. The two pedestrian bridges would have localized, long-term, minor, adverse impacts on the river’s hydrology and floodplain values. Local, short-term, minor, adverse impacts on hydrology may occur during construction due to construction activities in the main channel.

EL PORTAL WATER QUALITY

Actions to implement the River Protection Overlay would reduce discharge of non-point source pollutants into the river by providing a buffer area where development is removed (e.g., at Hennessey’s Ranch) and future development is constrained (e.g., at Village Center and Railroad Flat). Water quality could be adversely impacted at Village Center by runoff associated with increased parking spaces for both visitors and employees, although this impact would be mitigated by non-point source pollution controls at large paved areas. The increase in employees living in El Portal would likely result in increased recreational use of the river and subsequent increase in fecal coliform and bacteria levels, resulting in a regional, long-term, minor, adverse impact on water quality. Wastewater from all new buildings (e.g., housing, park headquarters, etc.) would be connected to the existing sanitary sewage system and would meet all applicable water treatment requirements. The impacts of this alternative on water quality in El Portal would be localized, long-term, minor, and adverse due to increased non-point source pollution resulting from increased development.

FORESTA HYDROLOGY AND WATER QUALITY

The project site at Foresta is approximately three-quarters of a mile from Crane Creek, but has no rivers, streams, or other hydrologic features, and surface runoff is the only pertinent hydrologic process. A Volunteers-in-Parks campground, 14 houses, and a new National Park Service stable at McCauley Ranch would be constructed (depending on the outcome of the Wilderness Feasibility Study) in the Foresta area. These actions would have a localized, long-term, negligible, adverse impact on hydrology, resulting from reduced ground cover and potentially increased runoff. These actions would result in increased non-point source pollution, which would be mitigated through stormwater pollution controls at the parking facility, and have a localized, long-term, minor, adverse impact on water quality.

SOUTH LANDING HYDROLOGY AND WATER QUALITY

South Landing has no significant hydrologic features, and surface-water runoff is the only pertinent hydrologic process. The construction of a parking facility would have localized, long-term, minor, adverse impacts on hydrology resulting from reduced ground cover and potentially increased runoff. Construction of a parking facility would increase non-point source pollution, which would be mitigated through stormwater pollution controls, and would have a localized, long-term, minor, adverse impact on water quality.

BADGER PASS HYDROLOGY AND WATER QUALITY

The project site at Badger Pass has several springs, seeps, and wetlands that form the headwaters of Grouse Creek. The hydrology of these headwaters and surface water runoff are the only pertinent hydrologic processes. The construction of a parking facility that is approximately the same size as the current parking lot and expanded visitor use facilities would have a localized, long-term, minor, adverse impact on hydrology resulting from reduced ground cover and potentially increased runoff associated with the expanded visitor use facilities. This parking facility would have a localized, long-term, minor, adverse impact on water quality resulting from increased non-point source pollution due to use of the parking area for longer periods of time.

BIG OAK FLAT, TIOGA PASS, AND SOUTH ENTRANCE
HYDROLOGY AND WATER QUALITY

The locations of these entrance stations have no major rivers, streams, or other hydrologic features. Surface-water runoff is the only pertinent hydrologic process. A visitor center and associated visitor service facilities would be constructed, resulting in reduced ground cover and potentially increased runoff. These actions would have a localized, long-term, negligible, adverse impact on surface water hydrology. These actions would have a localized, long-term, negligible, adverse impact on water quality resulting from increased non-point source pollution associated with development.

CONCLUSION

The collective actions of this alternative have regional, long-term, moderate, beneficial impacts on hydrology and water quality, largely due to the removal of facilities in Yosemite Valley from the River Protection Overlay and the 100-year floodplain and removal of the bulk fuel storage facility in El Portal. The beneficial impacts of removing four bridges, Cascades Diversion Dam, campsites, Housekeeping Camp units, etc., have been weighed against the adverse impacts on hydrology and water quality in El Portal due to increased development near the river.

CUMULATIVE IMPACTS

This section assesses the impacts of past, present, and reasonably foreseeable future actions to water resources. The actions identified below have generally occurred within the watershed of the Merced River–both main stem and South Fork.

Past Actions

The water resources of the Merced River have been historically affected by a variety of actions within the floodplain since Euro-American settlement. In Yosemite Valley, the transportation network interferes with flooding and surface-water flow, and lodging, campgrounds, and other structures have been constructed in and immediately adjacent to the river channel. In El Portal, a large portion of the riverbank has been artificially stabilized to protect primary roads and buildings immediately adjacent to the river. Because artificial stabilization of the riverbank began in the 1800s, the Merced River has been separated for decades from substantial portions of its floodplain. During spring runoff floods, this riprap serves to keep the channel from moving, and quickly conveys the water downstream. During winter floods, artificial bank stabilization prevents damage to dwellings and roads in the best-protected sections, but increases bank destruction where there is little or no artificial bank stabilization.

Present Actions

The El Portal Road Improvement Project (NPS) is currently under way from the park boundary to the Cascades Diversion Dam, and affects river-related communities of the Merced River immediately adjacent to the roadway. Natural resources are protected during construction by implementation of a compliance monitoring program, erosion and sediment controls, hazardous materials controls, revegetation and reclamation, and excluding construction from sensitive habitats. Between El Portal and Yosemite Valley, riprap has been placed in some locations along the north bank of the Merced River to protect the reconstructed El Portal Road, altering the overall flow regime of the river.

Reasonably Foreseeable Future Actions

Reasonably foreseeable future actions proposed in the region are separated below into four general categories: (1) projects expected to have a net beneficial impact; (2) projects expected to have both beneficial and adverse impacts; (3) projects expected to have a net adverse impact; and (4) projects that have no impact relative to the actions of this alternative.

Reasonably foreseeable future projects that could have a net beneficial impact on water resources of the Merced River include:

• The Merced River at Eagle Creek Ecological Restoration Project (NPS)

• Merced Wild and Scenic River Comprehensive Management Plan (NPS)

• Yosemite Wilderness Management Plan Update (NPS), which will address land management issues within the wilderness

• Fire Management Plan Update (NPS)

• Potential Land Use and Management on Lands Adjacent to Yosemite National Park (Sierra Nevada Framework for Conservation and Collaboration).

• Several transportation-related projects (e.g., Yosemite Area Regional Transportation System [inter-agency]), which have the general goals of increasing transportation options and reducing reliance on automobiles in the area

• Replacement/Rehabilitation of Yosemite Valley Sewer Line (NPS)

• South Fork Merced River Bridges Replacement (NPS)

• Bridalveil Horse Camp Rehabilitation (NPS)

• Yosemite Creek Campground Restoration (NPS)

• Wawona Campground Rehabilitation (NPS)

These projects would have net beneficial impacts on water resources through improved coordination of resource management activities and restoration, although there might be site-specific or short-term, adverse impacts.

Reasonably foreseeable future projects that could have both beneficial and adverse impacts on water resources include:

• Merced River Canyon Trail Acquisition (BLM)

• Mariposa Grove Roadway Improvement and Giant Sequoia Restoration (NPS), which would remove parking from the Lower Mariposa Grove of Giant Sequoias, restore the area, and realign the intersection at the South Entrance Station.

• Rogge — Ackerson Fire Reforestation (Tuolumne Co.), which would improve slope stability and reduce sedimentation by reforesting 5,000 acres; however, activities could also adversely impact water quality by burning, tilling, and herbicide application.

• A-Rock Reforestation (USFS, Stanislaus), which would improve slope stability and reduce sedimentation by reforesting 4,500 acres; however, activities could also adversely impact water quality by burning, tilling, and herbicide application.

These projects would have beneficial impacts on water resources by removal of facilities, restoration, and slope stabilization, and adverse impacts on water resources through increased non-point source water pollution.

Reasonably foreseeable projects that could have a net adverse impact on water resources include:

• The Yosemite View Parcel Land Exchange, El Portal (NPS)

• Merced River Canyon Trail Acquisition (BLM)

• Yosemite Motels Expansion, El Portal (Mariposa Co.)

These projects would have adverse impacts on water resources through increased use and facility development, which could result in stream bank instability and increased non-point source water pollution.

Beneficial impacts on water resources of past, present, and reasonably foreseeable future projects on the Merced River watershed would be related to removal of facilities from the riverbanks and floodplain, restoration of previously developed areas and areas significantly impacted or altered by visitor use, removal of channel obstructions, and reduced human-related impacts. Adverse impacts of these projects on the Merced River watershed would be related to increased use and facility development, which could result in stream bank erosion, soil compaction, loss of vegetation, refuse accumulation, non-point source pollution generation, and degradation of stream characteristics and water quality in the Merced River. Overall, the past, present, and reasonably foreseeable future projects would have a long-term, minor, beneficial impact on water resources. The actions of this alternative would have a long-term, minor, beneficial impact on water resources. The actions of this alternative, in combination with past, current, and reasonably foreseeable future projects, would have a long-term, minor, beneficial impact on water resources.

This evaluation identifies non-exempted actions within the floodplain that could increase or decrease risk to human life and property by adding or removing housing and facilities from floodplains. The proposed removal and addition of non-exempted facilities from the floodplain are listed below by area and summarized in table 4-88; all impacts would be long-term unless otherwise noted (see plate E for Yosemite Valley flood extent). For related effects on floodplain values and hydrology, see the Water Resources section in this chapter.

YOSEMITE VALLEY

Cascades Diversion Dam

Dam safety engineers have classified the Cascades Diversion Dam as a "high hazard potential structure" and assigned a Safety of Dams condition of "unsatisfactory." This classification requires immediate corrective action. The removal of the dam would be a long-term, localized, major, beneficial impact to human health and safety.

Concessioner Stable Area

A moderate, beneficial impact would result from the removal of houses and tent cabins (49 employee beds) and the concessioner stable from the floodplain. This beneficial impact would be related to reduced risk to both human life and property during a flood event. The removal of the kennel from the floodplain would result in a negligible, beneficial impact because potential property damage due to flooding would be reduced.

Housekeeping Camp

The removal of 212 housekeeping units and retention of 36 units in the 100-year floodplain would result in a moderate, beneficial impact because overnight lodging within the 100-year floodplain would be reduced, decreasing flood-related risk to both human life and property. Compared to the No Action Alternative, the beneficial effect related to human life would be limited, however, because the units are not in use during the winter flood season.

Yosemite Village

Removal of the Concession Headquarters, Indian Creek employee housing (14 employee beds), and three Ahwahnee Row houses (three employee beds) from the floodplain would result in an overall moderate, beneficial impact because fewer people would be living and working within the floodplain, and flood hazard related to human safety would be reduced. Redevelopment of this area would minimize placement of structures in the floodplain and include mitigation measures to protect people during flood events. With mitigation, in accordance with National Park Service Floodplain Management Guideline, risk to both human safety and property would be a minor, adverse impact.

1. Development may be in or surrounded by the floodplain2. Impact intensity listed is after implementation of mitigation. All impacts would be long-term unless otherwise noted.

Yosemite Lodge Area

Removal of the Superintendent’s House (Residence 1) and five motel units from the floodplain would result in a moderate, beneficial impact because overnight lodging within the floodplain and the associated risk to human safety and property would be reduced. Relocation of the Wellness Center and nearby custodial cabins outside the floodplain would also result in a minor, beneficial impact because the number of facilities and people working within the floodplain would be reduced, resulting in a reduction in the flood hazard related to human safety and property. New overnight parking would be developed that incorporates design standards to minimize the effect on floodflow and allow for runoff, resulting in a negligible, adverse impact. Adverse effects in the Yosemite Lodge area would be further reduced by designs that minimize impacts on natural flood processes and flood damage to structures, and by preparation of evacuation plans and routes (evacuation routes would be located outside the floodplain).

EL PORTAL

Village Center

Moderate, beneficial impacts at the Village Center would result from the adaptive reuse of El Portal Hotel (removal of 12 employee beds and relocation of Yosemite Institute Office), and the removal of the Motor Inn cabins (24 employee beds) because overnight occupation of the floodplain would be reduced. Removal of the bulk fuel storage facility would result in a moderate, beneficial impact on human safety because the number of people working within the floodplain would be reduced. Adaptive reuse of these facilities would include mitigation consistent with National Park Service Floodplain Management Guideline to reduce the risk of property damage due to flooding.

Parts of the Village Center area that would be redesigned to support commercial services and parking would be placed out of the floodplain where possible. For new structures constructed in the floodplain an evacuation and safety plan would be developed. With these mitigation measures in place, there would be a minor adverse impact.

Hennessey’s Ranch

The construction of 656 new employee beds at Hennessey’s Ranch would be a major, adverse impact on human safety because employee beds would be constructed within the 100-year floodplain. However, because mitigation would be incorporated into the design to protect employees and structures during flood events (e.g., raising and extending the levee, evacuation planning), the overall impact would be reduced to moderate and adverse.

WAWONA

There would be no impact to the South Fork Merced River floodplain because the employee housing considered for Wawona would be outside the floodplain.

CONCLUSION

Beneficial impacts in Yosemite Valley would include removal from the floodplain of 212 housekeeping lodge units, the kennel, concessioner stables and associated housing (49 employee beds), the Superintendent’s House (Residence 1), five Yosemite Lodge motel units, the Wellness Center and nearby custodial cabins, and 14 employee beds at Indian Creek. The Concession Headquarters and Indian Creek employee housing would be redeveloped as parking/visitor services, and new overnight parking would be developed at Yosemite Lodge which would have a minor, adverse impact on the floodplain. Overall, the aggregate impact of these actions in combination with mitigation in Yosemite Valley would be moderate and beneficial, because the flood-related risk to human safety and property would be reduced.

Actions in El Portal would include removal from the floodplain of 36 employee beds (moderate, beneficial) and the bulk fuel facility (moderate, beneficial), removal or adaptive reuse of El Portal Hotel (employee housing and Yosemite Institute Office; moderate, beneficial), 656 employee beds at Hennessey’s Ranch (moderate, adverse), and redevelopment of Village Center (minor, adverse). Beneficial impacts would be related to reduction of in the flood-related hazard to human safety. Adverse effects to both human safety and property associated with new development or redevelopment/adaptive reuse within the floodplain would be minimized by mitigation (e.g., design and siting specifications, extending and raising existing levees, and a mandatory evacuation plan) resulting in a net minor, adverse impact.

The total net effect of Alternative 4 would be moderate beneficial, because the number of people working and overnight lodging/housing within the floodplain would be reduced (reducing flood-related risks to human safety), and mitigation would be implemented to reduce adverse effects on human safety and property associated with development/redevelopment within the floodplain.

CUMULATIVE IMPACTS

The impacts of past, present, and reasonably foreseeable actions to floodplain values discussed herein are based on analysis of past, present, and reasonably foreseeable future actions in the Merced River watershed from its source near the crest of the Sierra Nevada to Briceburg Bridge. The actions identified below include those projects that have the potential to affect the floodplain of the Merced River.

Past Actions

The Merced River has been historically affected by a variety of actions within the floodplain since Euro-American settlement. In El Portal, from the park boundary to Briceburg Bridge, a large portion of the riverbank has been artificially manipulated. Much of this manipulation is riprap used to stabilize the riverbanks by the California Department of Transportation to protect Highway 140. The National Park Service and Yosemite Motels also placed riprap in the Merced River channel to rebuild roads (e.g., Foresta Road) and protect buildings immediately adjacent to the river. Because stabilization of the riverbank began in the 1800s, the Merced River has been separated for decades from substantial portions of the floodplain in the Merced River Canyon. During spring runoff floods, this riprap serves to keep the channel from moving, and quickly conveys the water down to Lake McClure. During winter floods, bank stabilization prevents damage to dwellings and roads in the best-protected sections, but increases bank destruction where there is little or no bank stabilization.

Present Actions

No current actions are increasing or decreasing flood-related risk to human life. Between El Portal and Yosemite Valley, riprap has been placed in some locations along the north bank of the Merced River to protect the reconstructed El Portal Road. This riprap would have essentially no flood-related risk to life or property.

Reasonably Foreseeable Future Actions

Reasonably foreseeable future actions that could have a potential cumulative beneficial or adverse effect on risk to human life and property during flood events are:

• El Portal, Trailer Village Closure (NPS)

• Yosemite Motels Expansion, El Portal (Mariposa Co.), (approximately 148 new hotel units)

• Yosemite View Parcel Land Exchange (NPS)

Cumulative effects of past, present, and reasonably foreseeable future actions would have both beneficial (e.g., implementation of the Trailer Village Closure Plan) and adverse (i.e., increased development of overnight lodging units and offices within the floodplain at El Portal) impacts on human life and property during flood events. In El Portal, approximately 59 employee trailers with 68 employee beds at Hennessey’s Ranch (currently Trailer Village) would continue to be scheduled for removal from the 100-year floodplain. This action which occurs outside the scope of actions considered in the Final Yosemite Valley Plan/SEIS, is in accordance with the current provisions of the Trailer Village Closure Plan (NPS 1993b). Cumulative adverse impacts of these potential future projects on the floodplain hazard of the Merced River would be related to increased overnight use and facility development. In El Portal, potential overnight residents and hotel visitors would slowly increase from approximately 1,300 to about 1,600 beds because of the Yosemite Motel’s expansion and the Yosemite View parcel land exchange. This represents an increase of approximately 25% in the number of people potentially affected during a flood.

Overall, the past, present, and reasonably foreseeable future actions listed above would have a long-term, moderate, adverse effect on risk to human life and property due to the amount and type of new development planned within the floodplain. The total net effect of Alternative 4 would be moderate and beneficial, because overnight lodging/housing within the floodplain would be reduced (reducing flood-related risk to human safety), and mitigation would be implemented to reduce adverse effects on human safety and property associated with development/redevelopment within the floodplain. Effects associated with this alternative, in conjunction with other past, present, and reasonably foreseeable future cumulative actions, would be long-term, minor, and adverse, because potential flood-related impacts to human safety and property from cumulative actions outside the scope of the Final Yosemite Valley Plan/SEIS (e.g., increased overnight lodging within the floodplain in El Portal would increase flood-related risk to human safety and property) would outweigh the beneficial impacts of this alternative.

In this section, wetlands were evaluated in the following locations: Yosemite Valley, El Portal, Badger Pass, Foresta, South Entrance, and Tioga Pass. The Wawona and Big Oak Flat Entrance locations have no wetlands, and are not discussed below. No actions are proposed at South Landing, Hazel Green, or Henness Ridge in this alternative.

SIZE

Yosemite Valley

Wetland impacts would take place in the wetland types shown on table 4-89. Acres of impacts are estimated based on geographic information system analysis of acres of meadow and riparian vegetation types from the Yosemite Valley vegetation map (NPS 1994e). In Yosemite Valley, about 149 acres of wetlands would be restored, seven acres of new development in wetlands would take place, and 11 acres of redevelopment in potential wetlands would occur under this alternative (table 4-89). Overall, this would be a long-term, major, beneficial impact on the size of wetlands in Yosemite Valley.

Restoration of wetlands would take place primarily at Yosemite Lodge, River Protection Overlay and highly valued resource areas at Housekeeping Camp, Upper and Lower River Campgrounds, Camp 6, parts of Lower Pines Campground, North Pines Campground, Backpackers Campground, Group Campground, and Swinging Bridge Picnic Area.

New development in wetland areas would take place on seven acres. Wetland delineation would be completed prior to the planning and design phase for Curry Village, where potential wetlands have been identified, to maximize opportunities for wetlands avoidance and minimization of adverse impacts. If wetlands are present in the area, adverse impacts would be avoided during site design and minimized through design modifications to the greatest extent practicable. If potential adverse impacts on wetlands are disclosed in subsequent planning efforts, additional compliance documentation would be completed as appropriate.

Potential impacts to wetlands would require a Wetland Statement of Findings in accordance with Director’s Order #77-1. Wetlands proposed for restoration by the Final Yosemite Valley Plan/SEIS would be counted toward the compensation of wetlands if needed for future compliance. A wetland delineation and a functional analysis would be included in each Statement of Findings. A U.S. Army Corps of Engineers 404 permit would be prepared as required.

Redevelopment in potential wetlands under Alternative 4 would total about 11 acres (see table 4-89). The larger areas of redeveloped wetland would occur at Sentinel Picnic Area and Upper Pines Campground. Wetland delineation would be completed prior to the design phase for the Sentinel Beach Picnic Area, where potential wetlands have been identified. Wetland delineation would be completed prior to the design phase for the Sentinel Beach Picnic Area, where potential wetlands have been identified. Wetland delineation has been completed for Upper Pines Campground (Kleinfelder 1998). Redevelopment within wetland boundaries would be avoided in the Upper Pines Campground area. Redevelopment in areas adjacent to wetlands would occur primarily at the former cabin area at Yosemite Lodge, the proposed road south of Yosemite Lodge, Yosemite Village, and the Ahwahnee parking lot (see table 4-89). Minor beneficial impacts could take place on neighboring wetlands if water flows that sustain adjacent wetlands are improved in project design.

Redeveloped wetlands may be considered an adverse impact if the sites still qualify as wetlands. Procedural Manual #77-1, Section 5.4 states that "development activities proposed for wetland sites that have been modified or degraded as a result of human activities" (but still meet the wetland definition) are considered "new actions" subject to Director’s Order #77-1 and other statutes. Consequently, degraded wetlands should not be treated as preferred development sites simply because they are already in an impacted condition.

Out-of-Valley Areas

No impact on the size of wetlands would occur in El Portal, Badger Pass, Tioga Pass Entrance, or Foresta.

INTEGRITY

Yosemite Valley

The integrity of wetlands would be improved by actions proposed in Alternative 4 in terms of the ratio of non-native to native species in palustrine emergent wetlands, and with restoration of soils, hydrology, and native wetland plant species along the Merced River. The removal of roads in low-lying areas would likely improve water flows, and restore naturally high water tables that sustain wetland conditions. Implementation of the River Protection Overlay and restoration of former and existing campgrounds to natural conditions would decrease foot traffic along the Merced River and allow riverside vegetation to become reestablished.

Foot traffic in the vicinity of Taft Toe would increase in nearby wetlands along the Merced River resulting in major, adverse impacts to wetlands in this relatively undisturbed area. The elimination of guided trail rides (though not private stock use) could benefit wetlands by eliminating associated manure, which could flow into wetlands and result in unnaturally high levels of nutrients that could harm wetland functions.

Road- and trail-related activities that could benefit wetland integrity include the removal of roads through Stoneman Meadow and the south part of Ahwahnee Meadow and restoration of the area.

Road- and trail-related activities that could have adverse impacts on wetlands include widening Southside Drive from El Capitan crossover to Curry Village to accommodate two-way traffic, constructing a multi-use trail from Swinging Bridge to El Capitan crossover, realigning Northside Drive along the southern perimeter of Yosemite Lodge, and constructing a new bridge across Yosemite Creek. These new roads and trails would directly impact some riverine and palustrine forest and scrub shrub wetlands at Sentinel Creek and along the Merced River and Yosemite Creek. All new roads, multi-use paved trails, and road widening would be designed to accommodate natural water flow patterns to mitigate direct and indirect impacts. Under Alternative 4, the removal of roads from meadows and the implementation of the River Protection Overlay would have a major, long-term, beneficial impact on the integrity of wetlands Yosemite Valley.

Out-of-Valley Areas

In El Portal, implementation of the River Protection Overlay and protection of existing wetlands at Hennessey’s Ranch through site design would minimize impacts to wetland integrity. Rebuilding the levee could have direct adverse impacts to the wetlands with the levee alignment, but these impacts would be minimized by restoration of the river corridor between the levee and the river’s edge through this area. Should parking be constructed near the El Portal Community Hall, site design would protect the palustrine forest wetlands in the historic river channel. Overall impacts on wetlands in El Portal are expected to be long-term, minor, and adverse, and would not affect the overall viability of wetlands in the area.

No wetlands would be directly impacted at Badger Pass or Tioga Pass Entrance, though impacts on adjacent wetland integrity could occur as a result of increased foot traffic. Foot traffic would be directed away from wetlands, though some additional foot traffic is expected to continue in the wetland area, with minor, adverse impacts. Impacts on the integrity of wetlands would occur in Foresta through increased use of the area through the relocation of stable operations to McCauley Ranch and the addition of 14 employee houses. The site design would avoid wetlands adjacent to McCauley Ranch. Radiating impacts that could result from additional nutrients and potential non-native plant species introductions would be avoided with aggressive management of stock waste and feed.

CONNECTIVITY

Yosemite Valley

Wetlands along the entire Merced River corridor in Yosemite Valley would be restored, reconnected, and protected from future degradation with restoration of Upper and Lower Rivers and other campground and facilities, resulting in major, beneficial impacts to riverine and palustrine forest and scrub shrub wetlands. Roads would be removed from Stoneman and Ahwahnee Meadows. The actions proposed in Alternative 4 would connect palustrine emergent wetlands in the east Valley from Stoneman Meadow and Royal Arch Meadow to Bridalveil Meadow. This would be a long-term, major, beneficial impact on wetland connectivity in Yosemite Valley.

Out-of-Valley Areas

No additional adverse impacts on wetland connectivity would occur in El Portal, Foresta, Badger Pass, South Entrance, or Tioga Pass Entrance beyond those described in Alternative 1.

CONCLUSION

Under Alternative 4 there would be a 131-acre net gain in the size of wetlands. Implementation of the River Protection Overlay and the removal of roads in Stoneman and Ahwahnee Meadows would substantially enhance the integrity of existing palustrine emergent wetlands. This would enhance natural processes such as flood interactions between the main Merced River channel and riverine wetlands, riparian borders of palustrine forest and scrub shrub wetlands, and palustrine emergent wetlands that are necessary to sustain healthy wetlands. Wetlands in the vicinity of Taft Toe would be impacted by increased visitor use. The actions that are proposed in Alternative 4 would have a long-term, major, beneficial impact on the size, integrity, and connectivity of wetlands in Yosemite Valley. Minor, adverse impacts to wetland integrity would occur to out-of-Valley areas at the El Portal, Foresta, Badger Pass, and Tioga Pass Entrance with implementation of mitigation measures.

CUMULATIVE IMPACTS

Past, present, and reasonably foreseeable future actions that could impact wetlands are all considered to be long term.

Regional and parkwide planning efforts such as the Sierra Nevada Framework for Conservation and Collaboration (USFS); U.S. Forest Service management plans for adjacent wilderness; the Wilderness Management Plan Update (NPS); and the Fire Management Plan Update (NPS) could provide benefits to the size, integrity, and connectivity of wetlands. Cooperation among land management agencies would increase the opportunity to share common objectives and improve resource protection. These plans could also increase knowledge of resources and recreational use; they have the potential to have long-term, moderate, beneficial impacts on wetlands, though the proposed management direction has not been finalized. The Merced Wild and Scenic River Comprehensive Management Plan would have long-term, major, beneficial impacts on wetlands through zoning and management designed to protect and restore the river system and adjacent wetlands.

The Tuolumne Meadows Water and Wastewater Improvements (NPS) project and the Mariposa Creek Pedestrian/Bike Path (Mariposa Co.) project are in the early planning stages. Until the scope of these projects is determined, it is not possible to determine the extent of impacts on wetlands in these areas.

Other projects approved or planned for construction that could have beneficial effects on wetlands include campground rehabilitation projects in Tamarack, Yosemite Creek, Bridalveil, and Hodgdon Meadows Campgrounds, and the Merced River at Eagle Creek Ecological Restoration Project (Yosemite Valley). Erosion control and mitigation as a result of these projects could enhance and strengthen palustrine forest and palustrine scrub shrub wetlands. The Eagle Creek project would revegetate currently impacted riverbanks with benefits to palustrine forest and palustrine scrub shrub wetlands. The erosion control and restoration projects would have long-term, localized, and therefore minor, beneficial impacts on wetlands.

Projects approved or planned for construction that could have adverse effects on wetlands include the Yosemite View Parcel Land Exchange (NPS), University of California Merced campus (Merced Co.), and the Hazel Green Ranch (Mariposa Co.) project. The Yosemite View Parcel Land Exchange could directly impact existing palustrine forest and palustrine emergent wetlands along the Merced River corridor. A wetland zone traverses the Hazel Green Ranch site which could be impacted by radiating use, though proposed new development would not take place within the wetland corridor. The long-term direct, impacts on wetlands would be moderate and adverse due to the relative rarity of undeveloped wetlands between the elevations of 1,000 and 3,000 feet and the relative importance of remaining wetland habitat in the Sierra Nevada. Foothill areas below about 3,300 feet appear to have the greatest loss of wetlands of any region in the Sierra Nevada (UC Davis 1996a) and are particularly important in terms of their productivity and diversity.

The actions that are proposed in Alternative 4 would amount to a net gain of 131 acres of wetland in Yosemite Valley. Wetlands in meadows and along the Merced River would be enhanced by removal of roads and development such as campgrounds. Large-scale benefits to wetlands could take place as a result of regional and parkwide planning efforts such as the Sierra Nevada Framework for Conservation and Collaboration (USFS) and the Merced River Plan. Should substantial or full implementation of the actions included in these plans occur over time, long-term cumulative impacts on wetlands may, on balance, be moderate and beneficial. These regional plans are tempered by adverse impacts that include existing infrastructure to divert water away from wetlands in Yosemite Valley, the potential direct loss of wetland habitat at the Yosemite View Parcel Land Exchange (NPS), and with continued widening of the Merced River in the east Valley.

When the impact of the past, present, and future actions are combined with the actions proposed in Alternative 4, there would be a moderate, beneficial, cumulative impact on wetland size, integrity, and connectivity.

The following discussion identifies and characterizes the soils impacts expected from implementation of Alternative 4. Impact intensities are based on the size, type, and disturbance history of the soil resources impacted; soil resources are identified as highly valued resource (HVR), resilient (R) or other (O). The primary activities that would affect soil resources are discussed for each of the project areas. Generally, adverse impacts to soils would include a combination of soil removal, profile mixing, compaction, erosion, and contamination. Beneficial impacts would occur as a result of soil restoration. Construction-related impacts (such as compaction from equipment and erosion) would be expected to be short-term and temporary, because they would be minimized through the use of Best Management Practices and would occur for a limited time. All other impacts are expected to be long-term unless otherwise noted.

YOSEMITE VALLEY

Approximately 291 acres would be affected by actions proposed under Alternative 4. Of this acreage, 141 acres would be highly valued resource soils, 112 acres resilient soils, and 38 acres other soils. Of the total area affected, 193 acres would be restored while 98 acres would be associated with new development. Construction-related (short-term) impacts would be negligible to minor because Best Management Practices would be used to minimize erosion and to contain construction activities to the immediate area. Some minor discrepancies between acreages in the text and table may occur due to rounding, differences in mapping sources, and because impacts less than 1 acre are not mentioned in the text. A summary of affected soils is found in table 4-90.

Curry Village

Approximately 28 acres would be affected by actions proposed under Alternative 4: 12 of these acres would be restored (O=12); and 16 acres would be developed (R=8, O=8). Alternative 4 would restore approximately three-fourths as much area as would be impacted by new development. All of the beneficial impacts associated with restoration would occur on other soil types (551 Miwok — Half Dome complex). No highly valued resource soils would be restored. Beneficial impacts were evaluated as minor. Development and redevelopment of lodging units, campgrounds, and development of a new picnic area would have adverse effects on 16 acres. Approximately half of those impacts would occur on other soil types (551 Miwok — Half Dome complex). Development impacts were evaluated as minor and adverse. Overall, the adverse effects outweigh the beneficial effects, with a net result of negligible, adverse impacts in Curry Village.

Yosemite Lodge

Approximately 51 acres would be affected by actions proposed under Alternative 4: 48 of these acres would be restored (HVR=23, R=24, O=1); and 3 acres would be developed (R=3). Nearly all of the impacts at Yosemite Lodge would be related to restoration activities. Additionally, a large portion of the soils to be restored (23 acres) would be highly valued resource soils. Restoration activities would have a major, beneficial effect at Yosemite Lodge. The adverse effects associated with building construction would impact only a small acreage of resilient soils. Adverse effects were evaluated as being negligible. The overall impact at Yosemite Lodge would be major and beneficial.

Yosemite Village

Less than 14 acres would be affected by actions proposed under Alternative 4: 13 of these acres would be restored (HVR =12, O=1); and less than 1 acre would be developed (R=1). Essentially all of the impacts at Yosemite Village would be beneficial, because the development activities would be focused on areas that are currently developed. All of the restoration would occur on highly valued resource soil types, including 151 El Capitan fine sandy loam and Leidig fine sandy loam. Overall, the proposed activities at Yosemite Village would have a moderate, beneficial impact on soil resources.

1. HVR = Highly valued resource soil, R = Resilient soil, O = Other soil (non-HVR and non-resilient)2. F=Flooding, SBE=Stream Bank Erosion, SE=Slope Erosion, HWT=High Water Table, D=Doughty (low water holding capacity), LOS=Loss of Organic Surface, C=Compaction, AC=Active Colluvium, B=Bedrock West ValleySource: Soil survey of Yosemite National Park, Yosemite Valley, California (SCS 1991)

West Valley

Approximately 54 acres would be developed by actions proposed under Alternative 4 (R=42, O=12). All of the activities proposed for west Valley would result in adverse impacts. Nearly all of these impacts would occur at Taft Toe as a result of parking facility construction. Resilient (Sentinel loams) and other soil resources would be primarily affected. Due to the relatively large area and type of soil resources affected, the overall impact would be moderate and adverse in the west Yosemite Valley.

Campgrounds

Approximately 144 acres would be affected by actions proposed under Alternative 4: 120 of these acres would be restored (HVR=106, R=12, O=2); and 24 acres would be developed (R=23, O=1). Restoration of campground areas and the 150-foot River Protection Overlay would have major, beneficial impacts on soil resources in the Valley. These impacts would occur on highly valued resource soils, whereas adverse impacts would occur on resilient soils. The overall impact of campground restoration in Alternative 4 would be major and beneficial.

Roads and Trails

Transportation corridors such as multi-use paved trails and roadways have the potential to affect multiple soil types. Generally, trail construction would occur adjacent to existing linear corridors such as roads or utilities, or would be upgrades of existing informal trails. The impact of new trail construction would be adverse; however, the impact would be minor since the impacts would primarily be in linear segments of previously disturbed soils. New trails would be constructed to accommodate surface and subsurface water flow. Additionally, upgrades to existing trails would decrease erosion in high-use areas. Overall, the construction of new roads and trails would have minor, adverse effects.

OUT-OF-VALLEY

Soils information is limited for many of the out-of-Valley locations. The following discussion is based on the general soils information available or extrapolated from other local soil surveys. It is assumed that out-of-Valley impacts would likely occur on resilient soil resources, because the geographic features outside of the Valley tend to be less constricting than those in the Valley. Disturbance to highly valued resource soils would be avoided as practicable, to reduce the likelihood of impacts on highly valued resource soils. General Best Management Practices and design requirements would reduce potential impacts to other soils. The following discussion is based on the premise that the majority of adverse impacts would occur on resilient soil resources, where feasible.

El Portal

All of the impacts at El Portal would be long term and adverse. Impacts would be related to the construction of parking facilities and employee housing. Soils within the El Portal area tend to be susceptible to mass movement and erosion, and have substantial development limitations. Construct techniques would require special measures to prevent erosion and soil movement. Due to the size of the proposed activities and the limited space available for construction, Alternative 4 would have a moderate, adverse impact on soil resources in the El Portal area.

Badger Pass

The soils at Badger Pass tend to be resilient and within the project area are mostly already disturbed. Provided that Best Management Practices are incorporated into the construction and design, additional impacts to soils would be minimized. Potential problems tend to be associated with moderate to steep slopes and erosion control. Construction of the parking facility would result in locally minor, adverse impacts.

South Landing

The site of the proposed parking facility has been previously used for slash piling/burning and contractor staging. The slopes within the area have a low to moderate erosion potential, and are not prohibitive for the proposed development. Generally, soils that would be impacted are previously disturbed and resilient. No impacts to highly valued resource soils would occur. This alternative would have a moderate, adverse impact on soil resources at South Landing due to its size.

Foresta

Impacts to soils in Foresta would occur if the National Park Service and concessioner stables are relocated to McCauley Ranch, and as a result of the reconstruction of employee beds destroyed in the 1990 A-Rock fire. However, impacts would be minor and adverse, because soils in these areas tend to be resilient and the area of impact would be relatively small.

Entrance Stations

Development and/or redevelopment of visitor centers near the existing entrance stations would result in adverse impacts to soil resources. The centers would be developed adjacent to existing stations, and generally would be located in areas suitable to the proposed use. The size of impact for each facility would be relatively small in relation to the surrounding soil resources. The impact due to construction of visitor centers would be negligible and adverse.

CONCLUSION

Three out of the five Valley locations would have overall beneficial impacts under Alternative 4, which proposes restoration of 193 acres and new development of 98 acres. West Yosemite Valley would have the largest adverse impact, largely due to construction of parking and circulation facilities at Taft Toe. This adverse impact would be offset to a large extent by the restoration of 142 acres of highly valued resource soils, 37 acres of resilient soils and 15 acres of other soil resources. All of the proposed development would occur on resilient or other soil resources. Thus, the overall in-Valley impact of Alternative 4 would be moderate and beneficial.

Overall, Alternative 4 would have beneficial impacts on 193 acres and adverse impacts on approximately 98 acres within Yosemite Valley and up to 70 acres out-of-Valley. The primary areas of beneficial impacts would be in highly valued resource soils at campgrounds, whereas adverse impacts would be concentrated in highly valued resource soils in West Yosemite Valley and at South Landing. Generally, the facilities that would be relocated outside of the park would disturb less sensitive resources than are currently being affected in the Valley. Furthermore, facility design and construction would use current technologies and Best Management Practices to minimize impacts. Out-of-Valley impacts would be locally moderate and adverse, but would occur on resilient soil resources at all locations except for El Portal. The overall impact for Alternative 4 would be minor and beneficial.

CUMULATIVE IMPACTS

The impacts of past, present, and reasonably foreseeable future areawide projects would be the same as described under Alternative 2, minor and adverse. In relation to the expected impacts resulting from areawide projects, the beneficial impacts related to restoration under this alternative would be substantial because they would be the primary beneficial impacts on soil resources that would occur in the region. Thus, the proposed project would serve to offset some of the adverse cumulative effects of other projects in the vicinity of the park. Therefore the cumulative impact of Alternative 4, in conjunction with other areawide projects, would be negligible and beneficial.

All impacts on vegetation are considered long-term unless otherwise noted. Short-term impacts would occur during construction or implementation of actions. Based on the mitigation measures to be taken (see Vol. Ia, Chapter 2), all short-term impacts are expected to be negligible.

The plant communities within out-of-Valley areas do not directly relate to the grouped vegetation types defined for Yosemite Valley due to elevation, terrain, and species composition differences. For example, the dominant plant species within a riparian vegetation type in El Portal would not be the same as those found within a riparian vegetation type in the Valley. Therefore, the vegetation types in each of the distinct out-of-Valley locations analyzed for this section are described separately from the vegetation types described for the Valley.

YOSEMITE VALLEY

The actions proposed under Alternative 4 would result in a net gain in all plant community types except upland and other. Table 4-91 summarizes the total areas of each vegetation type that would be adversely and beneficially impacted by this alternative. Minor discrepancies in totals between table and text are due to rounding to the nearest acre. It should be noted that the size of the area affected was only one of the factors used to evaluate impact magnitude. The continuity, productivity, structure, and diversity of the vegetation type were also factors considered in this impact analysis.

Approximately 91 acres of existing developed or disturbed areas within the Valley would be restored to natural vegetation through the actions described below. These would result in a major, long-term, beneficial impact to the vegetation of Yosemite Valley.

Due to their linear nature, transportation corridors (such as multi-use paved trails and roadways) would have the potential to affect multiple vegetation types. Therefore, rather than repeating this discussion under each vegetation type, road and trail impacts are described here. Under this alternative, new multi-use paved trail segments would be constructed. Generally, these trails would either parallel existing linear corridors such as roads or utilities, or would be located within areas that have been previously disturbed by past actions or social trails. The purpose of these new trail segments would be to provide connections to existing trails, thus improving the overall paved trail network for alternative modes of transportation through the Valley, and minimizing the need for cars. The impact of new trail construction would be adverse to vegetation; however, the impact would be minor to moderate given the small amount of vegetation impacted (8 acres). The impacts would occur primarily in previously disturbed uplands (non-highly valued resource), and the trails would be designed to avoid as many mature trees as possible as well as accommodate surface and subsurface water flow, although habitat fragmentation would be increased. Similarly, the three segments of realigned roadway and the one widened roadway would also have minor, adverse impacts on vegetation (3 acres). The new bridge over Yosemite Creek would effect a small area of California black oak vegetation (0.5 acre) adjacent to the existing bridge, resulting in a moderate, adverse impact.

Restoration of meadow (3 acres) and California black oak (0.5 acre) areas would occur as a result of removing Northside Drive within Ahwahnee and Stoneman Meadows and removing the turnout lanes at Northside Drive through El Capitan Meadow and Southside Drive through Sentinel Meadow. The impact on these vegetation types would be moderate and beneficial because they are both highly valued resources.

Overall, the road and trail impacts would have a minor, adverse effect on vegetation. The adverse effects would generally be to previously disturbed, non-highly valued resource types. The beneficial effects would restore highly valued resources, thus compensating for some of the adverse effects, but habitat would be lost permanently with additional pavement.

Upland Communities

Uplands make up the largest vegetation type within Yosemite Valley. Alternative 4 actions would result in the restoration of approximately 19 acres and the development of roughly 84 acres of upland vegetation in the Valley. The overall impact of this alternative on the upland vegetation would be minor and adverse, with improved forest health in remaining stands due to re-introduction of fire and reduction in non-native plant species.

New development in upland areas would occur throughout the east and central Valley but would generally be concentrated in areas that have been previously disturbed. Beneficial impacts would occur within the floodplain area of the east Valley, at the former Group and Backpackers Campgrounds (1 acre), Yosemite Lodge (6 acres), and Ahwahnee utility area (3 acres), as well as in the talus slope zone of Curry Village (9 acres).

Beneficial Impacts

The beneficial effects of Alternative 4 on the size, continuity, natural structure, diversity, and productivity of upland vegetation would be as described below, except the Church Bowl Picnic Area and Yellow Pine Campground would not be restored under Alternative 4 and the former gas station would be restored to upland and California black oak woodland communities.

At Yosemite Lodge, adjacent areas of ponderosa pine and California black oak would be restored in the middle of the Lodge area. The former gas station near Yosemite Lodge and former bank building at Yosemite Village would also be restored, thereby creating a larger, more continuous area of potential California black oak woodland. The action would result in a minor impact to upland communities in the area.

Beneficial impacts under Alternative 4 to upland vegetation size and continuity would occur within the following areas:

• At the former Group and existing Backpackers Campgrounds area, restoration would include small areas of upland vegetation mixed in with high-value vegetation types. This impact would be minor, beneficial.

• In the area between Yosemite Lodge and the Merced River, areas of restoration would provide a continuous California black oak and upland vegetation corridor, linking the upland areas to restored riparian and meadow areas. This impact would be moderate.

• In the Ahwahnee utility area (3 acres), the current utility area would be removed and restored to upland vegetation, thus restoring habitat continuity. This impact would be minor.

• In the talus slope zone of Curry Village (9 acres), the continuity of upland stands of canyon live oak would be improved by the removal of housing and restoration of the talus slopes. This impact would be moderate.

• At Yosemite Lodge, adjacent areas of ponderosa pine and California black oak at the former gas station would be restored. These actions would result in a minor impact to the upland community.

The beneficial impacts of Alternative 4 to natural structure, diversity, and productivity of upland vegetation are listed below:

• The canyon live oak community at Yosemite Village would be made more continuous through the removal of outbuildings in the vicinity of the NPS Operations Building (Fort Yosemite), with restoration of these areas to natural vegetation cover resulting in improved habitat and decreased fragmentation. This impact would be moderate.

• The ability to manage many of the continuous, unnaturally dense stands of incense-cedar and ponderosa pine with fire would be increased. This would help slow or stop the unnaturally rapid spread of annosus root rot through many of the currently developed areas of the east Valley (such as the Upper and Lower River Campgrounds area) and would improve overall forest health. This impact would be major.

• The need to manage hazard trees within and around developed areas would be reduced due to the restoration of many current upland vegetation areas and consolidation of development in other areas. Older individual trees and snags would be retained that provide important wildlife habitat. This impact would be minor.

• The productivity of smaller, more disjunct stands of upland coniferous vegetation would increase as a direct result of prescribed fire, reduction of stand densities, reduction in spread of annosus root rot (due to the reduction of stand densities), and establishment of understory herbaceous and shrub vegetation. This impact would be major.

• The understory integrity, diversity, and overall productivity of upland vegetation would continue to improve with the re-establishment of native understory, which would result from the reduction of trampling in developed zones in the east Valley. This impact would be moderate.

• The encroachment of upland vegetation into meadows and oak communities would be reversed through the use of fire management. The upland community would be reduced in size under Alternative 4 due to the removal of various developments in the east Valley, which would facilitate the ability of National Park Service staff to manage these areas with prescribed fire and other management tools. This would have a moderate effect on upland communities.

Adverse Impacts

Most of the adverse impacts to upland communities in the east Valley would be due to the construction of the new walk-in campgrounds east of the Upper Pines Campground, the new South Camp and Backpackers Campground, the addition of 15 sites at the Upper Pines Campground, the campground checkpoint, the new walk-to campgrounds near Tenaya Creek (18 acres), the new Curry Village housing/lodging (5 acres), and new lodging at Yosemite Lodge (5 acres). The adverse west Valley impacts would primarily occur at the Taft Toe Visitor/Transit Center and parking area (53 acres) and the North American Wall Picnic Area (2 acres).

Adverse impacts to size and continuity of uplands communities under Alternative 4 would include the following:

• At Yosemite Lodge, the addition of lodging in the area north of the existing Northside Drive and parking within the area would cause adverse, minor impacts to upland coniferous forest and canyon live oak communities due to the establishment of new buildings, paved walkways, and the need to trench underground to provide utilities to these structures. This area has been previously disturbed.

• At the Upper and Lower River Campgrounds area, upland communities would also be converted from existing upland back to a mosaic of California black oak, riparian, and meadow communities through the removal of fill material and re-establishment of natural drainage patterns. This would have only a minor impact on upland communities because this area does not have an intact understory and was not originally upland vegetation.

• The new walk-in campgrounds in the Valley would have a moderate impact on upland communities due to trampling of the understory layer.

• The addition of South Camp and the relocated Backpackers Campground would result in moderate upland impacts due to trampling and loss of understory vegetation.

• New lodging at Curry Village would be constructed outside of the talus slope zone near the existing lodging. This impact would be minor because the area is currently impacted by trampling.

• The development of the Taft Toe Visitor/Transit Center and associated facilities, with needed utilities, trenching, and the lack of management fires, would directly impact upland trees (ponderosa pine, incense-cedar, white fir, Douglas-fir, and some California black oak) due to paving and buildings. This development would also increase stresses to the remaining surrounding trees through trenching, trampling, and lack of smoke that controls oak gall development and spread of mistletoe in California black oaks. Irrigation in landscaped areas, if established, would result in a serious decline in the health, vigor, and productivity of this mixed ponderosa pine/California black oak forest. This impact would be moderate.

• Development of Taft Toe for a 550-space parking area with picnicking and a potential traffic check station would remove the unnatural density of forest stands at this site. This would also be a major, adverse impact to large specimens of incense-cedar, Douglas-fir, and white fir trees growing in and near the vicinity of Taft Toe.

• Radiating impacts from the Taft Toe Visitor/Transit Center would occur to adjacent upland, California black oak, riparian, and meadow (El Capitan meadow) communities, with increased trampling, soil compaction, loss of understory and herbaceous vegetation, and a greater potential for the establishment of non-native species from increased foot and vehicle traffic. This would result in a moderate, adverse, long-term impact to the upland area, as well as adjacent communities, in what is currently a relatively undisturbed and productive area of the Valley.

• The Taft Toe Visitor/Transit Center would cover portions of a large existing annosus root rot center, which could cause the rapid expansion of the root rot and dramatically increase tree mortality (due to trenching, potential irrigation, increased trampling impacts, and other increased stresses) in the mature trees in this area. This impact would be moderate.

• The need to manage hazard trees would increase in the west Valley from the continued vehicle use of Southside Drive, development of the Taft Toe Visitor/Transit Center, and improvement of facilities at Cathedral Beach Picnic Area (part of a large annosus root rot zone). This would result in the loss of older tree structure and contributions of old and dying trees and snags to habitat, which would result in a major impact.

• Construction of a multi-use paved trail adjacent to Southside Drive (from El Capitan crossover to Swinging Bridge) would create additional paved areas, with associated impacts to drainage, a direct loss of vegetation, and an increased level of habitat fragmentation. These trails would have a minor impact to upland communities due to their development adjacent to existing roadways, and existing levels of disturbance along these corridors.

• A number of the restoration actions proposed that would convert existing upland vegetation types to highly valued resource types (meadow, riparian, and California black oak). This would have a minor impact on upland vegetation community types because many areas to be converted were originally highly valued resource vegetation types that have since been modified due to human influences.

California Black Oak Communities

The California black oak vegetation type is considered a highly valued resource because of its transitional character between wet meadows and drier uplands as well as its links to wildlife and ethnographic resources. There are approximately 240 acres of California black oak habitat within Yosemite Valley. Under Alternative 4, the actions proposed would result in approximately 25 acres of beneficial impacts to this vegetation community and 7 acres of adverse impact. Compared to Alternative 1, the overall impact of this alternative on California black oak vegetation would be major and beneficial.

Beneficial Impacts

The restored California black oak areas are primarily in the campground areas (16 acres); Yosemite Lodge area (4 acres); the Curry, Lamon, and Hutchings Orchards (2 acres); Camp 6 (1 acre); the Ahwahnee tennis courts (1 acre); and the Superintendent’s House (Residence 1) (1 acre).

Beneficial impacts on the size and continuity of California black oak vegetation are listed below:

• The removal of North Pines Campground and the concessioner stable would facilitate a continuous ecotonal transition from the riparian communities near Tenaya Creek and the Merced River to more California black oak stands to the south and east, thus increasing the size of both communities as well as eliminating most of the habitat fragmentation in this area (except for the small development of the amphitheater in a portion of the former concessioner stable area). These actions would result in a long-term, major, beneficial impact.

• At Yosemite Lodge, adjacent areas of California black oak and ponderosa pine would be restored, creating a larger, more continuous area of potential California black oak woodland. Due to the presence of large annosus root rot populations in the area, landscaping would focus on California black oaks (which are resistant to annosus root rot) rather than conifers, thus leading to a greater proportion of oaks in this area. This action would result in a long-term, moderate impact.

• Ahwahnee Row houses would be removed and the area restored to meadow, riparian and California black oak vegetation types. This beneficial impact would be minor due to the small size; however, it would act as a buffer between human activities and the Ahwahnee Meadow.

• The fruit trees within the three Valley orchards would be removed and the areas restored to California black oak and meadow vegetation, which would be a moderate impact.

• Removal of the Ahwahnee tennis courts and associated non-native vegetation would remove the gap in this otherwise intact oak woodland that surrounds the courts, thus improving the continuity of the oak woodland through this entire area between the Upper and Lower River Campgrounds area and Ahwahnee Meadow to The Ahwahnee. Removal of the tennis courts would result in a moderate, beneficial impact.

• Removal of fill material at restoration sites such as the Upper and Lower River Campgrounds area would remove habitat for upland communities and restore original lower (topographic) layers to California black oak woodland, which would result in a long-term, major benefit.

The natural structure, diversity, and productivity of California black oak vegetation would benefit from Alternative 4 in the following ways:

• Stands in the east Valley would be minimally fragmented by development, roads, and encroaching conifers due to the enhanced ability of the National Park Service to manage areas with fire, removal of facilities, and restoration of areas such as the Ahwahnee tennis courts and the former Upper and Lower River Campgrounds area, into a mosaic of oak woodlands, meadows, and riparian areas. These actions would result in a moderate impact.

• The natural structure of California black oak stands in the west Valley would improve due to prescribed burning, with the subsequent reduction in conifer encroachment resulting in a moderate impact. Other components of California black oak communities, such as deer grass (an important ethnographic resource), would increase because of the reintroduction of natural and simulated natural processes (such as fire and corrections in drainages). This action would result in a moderate impact.

• Correction of drainage problems associated with roads (potentially on Northside Drive at El Capitan Meadow and Southside Drive in the Bridalveil Fall area) and the removal of roads through Ahwahnee and Stoneman Meadows would improve the condition of California black oak stands in these locations by re-establishing natural drainages, resulting in a major, beneficial impact. This would correct problems associated with the impoundment of water upslope of roads, which keeps soils wetter for longer periods during the summer, thus encouraging armillaria root rot to become fully established.

• Restoration of historic landscaping characteristics at the Yosemite Village Historic District housing area would improve the condition of existing mature California black oaks and facilitate the establishment of younger generations of these trees within the district, thus improving stand structure and increasing the continuity of stands in this portion of the Valley. A moderate, beneficial impact would result from the action.

Adverse Impacts

The adverse impacts would primarily result from the new lodging at Curry Village (5 acres) and the new South Camp walk-in sites (2 acres) and wilderness parking area (1 acre).

The size and continuity of California black oak vegetation would be adversely impacted by the following:

• The development of additional lodging units adjacent to Stoneman house would result in direct loss of some mature oak trees and loss of regenerating saplings, as well as understory structure and function. In addition, radiating human activities and lack of fire would continue encroachment by conifers, leading to a gradual shift from a California black oak-dominated community to a mixed conifer, California black oak type that is more common in the Valley. This action would result in a long-term, moderate impact to the vegetation community.

• The addition of the new South Camp walk-in sites would result in moderate impacts to California black oak vegetation due to trampling and loss of understory vegetation.

• Mature California black oak trees would potentially be removed during site grading and development, and additional trees could be lost with root impacts during construction, changes in drainage, and hazard tree removal, thus resulting in loss of stand structure and continuity throughout the Valley. These proposed actions would result in a moderate, adverse impact due to the long-term nature of California black oak regeneration if individual trees are lost.

• Removal of Superintendent’s House (Residence 1) and redevelopment of a portion of the site for a picnic area would increase the use of this area from its current condition. Trampling and a loss of vegetation on the ground as well as oak regeneration would result in a minor, adverse impact.

Meadow Communities

The proposed actions under Alternative 4 would result in beneficial impacts to approximately 52 acres of meadow habitat through restoration and negligible, adverse impacts to less than 0.5 acre of meadow habitat. The overall impact of this alternative on meadow vegetation would be major and beneficial.

Beneficial Impacts

Under Alternative 4, three general areas would be restored, with 25 acres near Yosemite Lodge, 20 acres in the former campgrounds, and 7 acres at Camp 6. Additional benefits to the meadow areas would be accomplished through the removal of bisecting roads through Stoneman and Ahwahnee Meadows, with improved water flows and a decrease in radiating impacts such as trampling.

The size and continuity, natural structure, diversity and productivity of meadow vegetation would be beneficially affected by the following:

• Ecological restoration of the entire area south of the proposed new road alignment at Yosemite Lodge (aside from utilities and access near the confluence of the Merced River and Yosemite Creek) would have major, beneficial effects on the ecological function of this section of the Valley, with increased meadow and riparian acreage, enhanced wetlands, and minimal fragmentation of a large low-lying area.

• Meadow size (of Ahwahnee and Stoneman Meadows from removal of roads) would increase substantially, with improved natural drainage patterns and continuous meadow cover over large areas of the east Valley. This would result in a major impact.

• Areas of former meadow at the Upper and Lower River Campgrounds area; Ahwahnee Meadow where it is bisected by Northside Drive, sections of Lower Pines Campground, Southside Drive near Bridalveil Fall, and Cook’s Meadow would be restored by unburying meadow soils where fill was added. Hydrology would be restored over time through the restoration of original topographic variations, and as a result, the dominance by non-native herbaceous species due to altered soil and hydrologic conditions in these areas would end. This impact would be major.

• Connectedness of meadows to riparian and wetland areas would be created by removing roads and reconstructing portions of returned roads to facilitate natural drainage patterns. This impact would be major.

• Implementing the River Protection Overlay, with access directed to appropriate sites along the river, would minimize impacts to this critical ecotone and result in a major impact.

• The modification of roads at Bridalveil, El Capitan, and Cook’s Meadows to allow for natural drainage would re-establish functioning oxbow and cutoff channels through meadows. This would create a critical link between meadow, and riparian systems, with increases in native plant establishment (due to wetter conditions), greater native biodiversity, and greater overall productivity due to changes in species, food for wildlife, cover, etc. Modifications to roads in these areas would result in a major impact.

• Development of a multi-use paved trail between Curry Village and Yosemite Village would potentially allow for removal of the boardwalk through north Stoneman Meadow, thus increasing the continuity of the meadow and adjacent oak woodland. This would result in a minor impact.

• Gradual decline of existing fruit trees and the eventual restoration of Lamon Orchard would return the area to a mosaic of California black oak, meadow, and riparian vegetation. This restoration would have local moderate, beneficial effects because of the restored diversity and structure and reduced fragmentation, even though it is a relatively small area.

• Restoration at Camp 6 would return this highly disturbed area to a mosaic of meadows and riparian vegetation type, which would result in major, beneficial impacts due to reduced habitat fragmentation and increased vegetation diversity.

Adverse Impacts

The proposed actions under Alternative 4 would result in the following negligible adverse impacts to the size, continuity, natural structure, diversity, and productivity of meadow vegetation in the Valley.

These impacts would result from radiating use from new developed areas such as the potential vehicle check station at El Capitan crossover, at the new picnic area at the site of the Superintendent’s House (Residence 1), and along new multi-use paved trails.

• Development of a multi-use paved trail between Curry Village and Yosemite Village through the Upper and Lower River Campgrounds area would not allow for complete elimination of fragmentation and impacts to existing and potential meadow and riparian zones. Alignment of the multi-use paved trail along the utility corridor through the Upper and Lower River Campgrounds area would minimize fragmentation somewhat by overlapping uses, resulting in a minor impact.

• Development of a vehicle management station, if required, at El Capitan crossover could result in undesired/unplanned parking along road shoulders at El Capitan Meadow, resulting in additional impacts from vehicles, trampling, the continued need to remove hazard trees, and introduction of non-native plant species into the meadow. However, these radiating impacts would be mitigated through restricting parking along the roadway and restricting human use of the meadow. The action would result in a minor impact to the meadow.

Riparian Communities

Actions under Alternative 4 would create beneficial impacts on more than 97 acres of riparian vegetation and result in an adverse impact to an estimated 7 acres of riparian habitat. The overall impact of this alternative on riparian vegetation would be major and beneficial.

Beneficial Impacts

Restoration would be concentrated in the floodplain areas near Yosemite Lodge (16 acres), Upper and Lower River, North Pines, Backpackers, Group, and portions of Lower Pine Campgrounds (59 acres), Camp 6 (5 acres) and Housekeeping Camp (12 acres), and Swinging Bridge Picnic Area (3 acres), as well as the talus slope zone of Curry Village (2 acres).

The beneficial effects of Alternative 4 on the size, continuity, natural structure, diversity, and productivity of riparian communities would be as described below. Also, under Alternative 4 restoration at Yellow Pine Campground would not occur.

• Restoration at Camp 6 would return this highly disturbed area back to a mosaic of meadows and riparian communities, which would have major, beneficial impacts resulting from reduced habitat fragmentation and increased diversity.

• The removal of Sugar Pine and Stoneman Bridges, as well as Housekeeping and Superintendent’s Bridges, would eliminate the hydrologic alterations that are causing a loss of riparian vegetation both upstream and downstream of these bridges. This would be a major, beneficial impact because it would allow creation of continuous riparian areas, with significantly reduced intrusions of infrastructure on the river corridor.

• Removal of North Pines Campground and the concessioner stable would facilitate a continuous ecotonal transition from the riparian communities near Tenaya Creek and the Merced River to drier California black oak stands to the south and east. This would increase the size of both vegetation communities as well as eliminate most of the habitat fragmentation in this area, except for the small development of the amphitheater in a part of the former concessioner stable area. The action would result in a major impact to the riparian and California black oak communities.

• Restoration of the Upper and Lower River Campgrounds area, the Upper Pines Campground dump station, a portion of Lower Pines Campground, a portion of Housekeeping Camp within the 150-foot River Protection Overlay, and Group and Backpackers Campgrounds would facilitate the re-establishment of riparian corridors (oxbows and cutoff channels) through these sites as well as along the Merced and Tenaya Creek, resulting in a major impact.

• Restoration of the riparian corridor at Camp 6 would improve the continuity of riparian habitat along the Merced River corridor through the east Valley, and would provide connection between the wetland and meadow communities to the northeast and northwest of the proposed parking area. This impact would be moderate.

• Ecological restoration of the entire area south of the proposed new road alignment at Yosemite Lodge (aside from utilities and access near the confluence of the Merced River and Yosemite Creek) would have major, beneficial effects on the ecological function of this section of the Valley. This restoration would increase the potential for more meadow and riparian acreage, enhanced wetlands, and minimal fragmentation of a large low-lying area.

• Yosemite Lodge landscaping would be designed to accommodate seasonal and ephemeral drainages, and channels would be revegetated with riparian species appropriate to the site to provide continuous riparian threads through the developed area. This would result in a moderate impact.

• Redesign of portions of Southside Drive in the Bridalveil Fall area would facilitate water flow under the road and enhance the continuity of the riparian community upslope and downslope of the existing road. This impact would be moderate.

• The removal of Swinging Bridge Picnic Area would improve the habitat condition of the riparian communities in this area, thus promoting the establishment of understory and herbaceous layers that are currently nonexistent. This action would result in a minor impact.

• Removal of the rubble pile from the western channel of Yosemite Creek would allow this channel to flow for a longer period, thus enabling riparian vegetation to become established in this currently barren channel. A moderate impact would result.

• Rehabilitation of bridges over Yosemite Creek in the braided stream channel area would remove impacts associated with undersized bridges that have resulted in scouring of the channel banks and loss of riparian vegetation. This would provide a moderate improvement to riparian conditions in this area, in conjunction with removal of the western channel human-built rock-rubble pile.

• Repair and construction of the road between the Cascades Diversion Dam and Pohono Bridge would eliminate roadside parking and associated human impacts on riparian vegetation along this section of the Merced River corridor, resulting in a minor beneficial impact.

Adverse Impacts

Adverse impacts to riparian vegetation under Alternative 4 would primarily take place at the new walk-in campsites at Upper Pines Campground (3 acres) and at the new lodging at Curry Village (4 acres). Additional impacts would occur as a result of radiating use from these new and redeveloped sites.

Impacts to size and continuity, natural structure, diversity, and productivity of riparian vegetation would be adversely affected by the following:

• New walk-in campsites at Upper Pines Campground would cause minor impacts to riparian vegetation due to trampling and the use of fill to create flat spaces for tent pads.

• At Curry Village, a small area of riparian vegetation would be impacted in order for existing lodging to be relocated outside of the talus slope zone. This new lodging development would be designed to minimize impacts. This would result in local impacts that are moderate but minor in relationship to the overall impacts to riparian vegetation.

• Converting the trail south of the Happy Isles Loop Road between Curry Village and Happy Isles to a multi-use paved trail would result in continued and increased negative impacts to the fen (an alkaline wetland fed from groundwater sources located near Happy Isles) and adjacent riparian vegetation. These impacts would be due to the widening of the current trail to accommodate heavier bicycle traffic, with a long-term loss of more fen habitat. This fen is the only one of its kind in Yosemite National Park and any impacts would be considered major due to the rarity of this type of vegetation community.

• Paving or hardening the eastern channel trail at Yosemite Creek for accessibility would directly impact some riparian vegetation because this action would involve widening or relocating the current trail. However, the area of impact would be small, and this site has already had an almost complete loss of herbaceous cover due to undirected foot traffic adjacent to the current access trail to Lower Yosemite Fall Bridge. The action would result in a minor impact.

• Development of a multi-use paved trail between Curry Village and Yosemite Village would continue to cause habitat fragmentation through the Lower Pines Campground area (for upland and California black oak). The paved trail would be designed to minimize impacts to the riparian zone between the Ahwahnee Bridge and Curry Village, accommodating frequent cutoff channel flows across the terrace. This would be a minor impact.

• Increased development of the existing Cathedral Beach Picnic Area could result in negative impacts to riparian vegetation due to impacts of picnic area development (with installation of restrooms, picnic tables, and barbecue grills, and trenching for utilities to support restrooms, running water, etc.), as well as impacts from radiating uses along the river. A trail currently exists along this bank, but the substantial increased use of the entire area would result in a much higher level of use, thus creating a wider path, a diversion of overland water runoff onto social trails, the trampling of vegetation, and an increased need to remove hazard trees. These impacts would be moderate with the implementation of fencing and signage to keep visitors out of sensitive vegetation.

• Development of a picnic area on a portion of the site formerly occupied by the Superintendent’s House (Residence 1) would result in increased radiating impacts to the Merced River from Alternative 1, with moderate, adverse impacts resulting from the loss of riparian vegetation through trampling and erosion.

Other Communities

The Alternative 4 actions would result in adverse impacts to about 4 acres of other types of vegetation ground cover. Thirty-two acres of bare ground, orchards, watered lawns, bare areas, and developed open areas would be restored to either upland or highly valued resource vegetation types. The beneficial impacts have been discussed in the upland, California black oak, meadow, and riparian discussions above, and include restoration of the Camp 6 area to a mix of meadow, riparian, and California black oak stands; restoration of the site of the removed concessioner stable at North Pines Campground to riparian and California black oak woodland; and restoration of the site of the former gas station near Yosemite Lodge to California black oak woodland. Adverse impacts would occur in areas where sparsely vegetated lands would be developed, such as the addition of a picnic area, housing, and lodging at Curry Village. Overall, there would be negligible beneficial impacts on these other vegetation types under Alternative 4.

OUT-OF-VALLEY

Out-of-Valley parking is proposed under Alternative 4 in the Badger Pass, South Landing, and El Portal areas as well as at the South Entrance, Tioga Pass, and Big Oak Flat entrances to the park. The overall impact of this alternative on out-of-Valley areas would be moderate and adverse. El Portal would be the only out-of-Valley area that would receive beneficial impacts as a result of Alternative 4.

El Portal

Vegetation types found in the El Portal area of impact include oak (a type of upland vegetation) and riparian types; however, the plant composition of these vegetation types varies from those in the Valley. Meadow and California black oak types are not represented in the El Portal area. The overall impact of Alternative 4 on El Portal vegetation would be moderate and adverse.

Upland Communities

• Existing oak stands would experience long-term, moderate impacts from the development of housing throughout El Portal. A direct loss of trees would occur with the development of housing within areas that are already somewhat impacted by low-density housing, as well as development of new housing sites at Hillside East and Hillside West. These developments would prevent retained trees from reproducing (due to pavement, yard activities, landscaping, trampling, and the presence of structures), resulting in a decrease in the size and continuity of these oak woodlands.

• The natural structure, diversity, and productivity of oak and upland communities would be moderately impacted because of the increased likelihood of non-native plant species and lack of natural fire and fire frequencies.

• Prescribed burning and mechanical treatment of vegetation surrounding El Portal would continue to maintain semi-natural stands of oaks around developed areas. These actions would promote oak regeneration by reducing competing vegetation. Many areas currently managed this way would be developed into housing, parking, and infrastructure, leaving fewer acres of oaks to regenerate, provide habitat, and add to the diversity of this area, which would result in a minor impact.

• The development of a parking area could require the removal of large individual oaks adjacent to the Merced River at Middle Road. The development of housing upslope of this site would eliminate connectedness of the oak stands on the slopes above El Portal with riparian and flat terrain oak communities. Impacts to vegetation would be moderate.

Riparian Communities

• The removal and restoration of the old treatment plant at Rancheria Flat adjacent to the river would enhance the continuity of riparian vegetation along this curve of the Merced River, with the potential for increased habitat for rare plant species growing adjacent to the site. This impact would be major.

• Implementation of the River Protection Overlay and management zoning, as prescribed in the Merced Wild and Scenic River Comprehensive Management Plan would help protect the riparian corridor throughout the El Portal Administrative Site, resulting in a minor impact.

• Restoration of the sand pit area in El Portal, with removal of remaining concrete wing wall and re-establishment of riparian vegetation, would enhance the river corridor and increase the potential habitat for Congdon’s woolly-sunflower, a state-listed rare plant species. This action would result in a minor benefit to the riparian vegetation community and Congdon’s woolly-sunflower.

• Riparian areas would receive minor impacts from the development of high-density housing at Hennessey’s Ranch (due to their currently impacted condition). Associated increase in human use would cause a decline in the continuity of this vegetation community as social trails develop.

• The size of riparian areas would continue to be impacted by existing developments and new developments (Hennessey’s Ranch and Village Center). A continued decline in riparian community size would also occur both in length along the river and width from the water’s edge up to the bank edge, which would result in a minor impact.

• An increased human population, and an associated increase in landscaping, numbers of vehicles, and foot traffic (and means for seed dispersion), would result in more non-native plant species problems throughout the riparian and oak woodland areas. This impact would be moderate.

• The isolated nature of riparian areas in the El Portal core area (Crane Creek to Foresta Bridge), caused by structures and Highway 140 riprap, would continue to inhibit natural exchange of other biological components (mammals, amphibians, and reptiles) as well as wind-dispersed seeds. This would result in lower overall productivity of these areas, representing a minor impact.

Foresta

The development being considered for Foresta under Alternative 4 includes stables and 14 additional employee houses. The area of potential impact would be approximately 2 acres for the relocated stable facilities. Housing impacts would occur within existing developed areas. The overall impact of Alternative 4 on Foresta vegetation would be minor and adverse.

Adverse Impacts

• Development of the National Park Service and concessioner stables at McCauley Ranch, including access road widening and rebuilding of a bridge along the access road, would further break up the continuity of the upland and riparian communities that exist along this road corridor. Impacts would be minor because the road and bridge are already present.

• Development of the National Park Service and concessioner stables at McCauley Ranch would also increase the possibility that non-native species could establish and spread. Foresta remains fairly susceptible to non-native plant establishment as a result of the severe impacts that occurred during the 1990 fires, because of constant ground disturbance, the need to maintain the road corridor, and importation of potentially contaminated feed. Stable operations could increase the chance of additional non-native plant species becoming established in the vicinity of the road and corral. This would result in a moderate impact.

• Isolated but extreme impacts from the establishment and spread of non-native plant species (including spotted knapweed, yellow star-thistle, and oxe-eye daisy) would occur at a somewhat more rapid rate due to increased vehicle use of this area from development of the stables and new housing. Management efforts would continue to attempt to contain and control (and eventually eradicate) existing and new non-native plant species. The spread of non-native species would be a moderate impact.

South Landing

The vegetation at South Landing includes a montane mixed conifer forest of ponderosa pine and incense-cedar, with sugar pine and greenleaf manzanita groundcover. A proposed day-visitor parking area and transit center would impact approximately 27 acres. The overall impact of Alternative 4 on South Landing would be moderate and adverse.

Adverse Impacts

• Montane chaparral and montane, mixed coniferous forest communities would be further impacted by the development of the parking area and transit center with the installation of associated utilities and infrastructure improvements, which would result in a moderate impact.

• Coniferous trees and montane chaparral species would be completely removed from large areas of South Landing due to grading and paving. Additional trees would be damaged during construction and would need to be removed in the future. Sugar pines could be stressed by changes in soil moisture and temperature from adjacent pavement, thus causing an increased susceptibility to white pine blister rust and leading to gradually higher rates of mortality. This would lead to a larger footprint of development over time as overstory trees die, resulting in a moderate impact.

• Radiating uses to the Crane Flat Meadow and the giant sequoias at the Merced and Tuolumne Groves from a substantially increased visitor population could result in increased herbaceous vegetation loss due to trampling, as well as a loss of diversity and function of vegetation due to the increased possibility of non-native plant introduction and establishment. These impacts could be minimized by installation of signing and fences to focus people away from sensitive areas and with increased management efforts to control non-native plant species, resulting in minor, adverse impacts.

• The development at South Landing would require management for hazard trees, resulting in the removal of older, decadent trees and snags that provide critical habitat for many wildlife species. Stands of sugar pine in this area are somewhat affected by white pine blister rust (a non-native rust that affects all white pines including sugar pine), and this would continue to affect the productivity and diversity of this site as well as adjacent stands. This impact would be minor.

Badger Pass

The vegetation within the area of potential development in the Badger Pass area includes white and red fir (upper montane forest). Under Alternative 4, a 415-space parking area would be developed within the existing ski area parking lot. Up to an additional 1 to 2 acres of new development would be required for associated utilities. The overall impact of Alternative 4 on the Badger Pass area would be major and adverse.

Adverse Impacts

• Parking for 415 vehicles would require the development of additional utilities to handle the increased demand for water and restroom facilities, thus leading to an expanded disturbance of shrubs and herbaceous plants within the conifer forest. This impact would be minor because the new parking area would be delineated within the existing parking lot. Therefore, the impact would be limited to the associated utilities required for summer use, as well as potentially increased radiating impacts from greater human use of the area during the summer.

Henness Ridge, Wawona, and Hazel Green

Under Alternative 4, no actions are proposed at Henness Ridge, Wawona, or Hazel Green.

Big Oak Flat Entrance

Additional parking and construction of a new visitor contact station (visitor center) would increase the footprint of the existing site by up to 5 acres. Impacts at the Big Oak Flat Entrance would be long term, minor, and adverse due to the small size of additional impact, the existing level of habitat fragmentation, and the existing high potential for the introduction of non-native plant species.

Impacts to upland vegetation (ponderosa pine forest and mixed conifer forest) may occur depending on the actual site design, which is not known at this time. Impacts would include paving, the removal of trees and groundcover, an increased difficulty of managing fuels and vegetation structure with fire (due to the presence of additional structures requiring fire protection), and trenching impacts to root systems (with a potential weakening of the health of directly affected trees).

Tioga Pass Entrance

Tioga Pass vegetation is characterized by a mosaic of both wet and dry subalpine meadows (dominated by native perennial grasses, sedges, rushes and forbs) and lodgepole pine forests. Continued degradation of these vegetation types would occur under Alternative 4. The impact resulting from this alternative would be long-term, moderate, and adverse, as there would be loss of vegetation and further degradation of vegetation community structure and diversity within a currently disturbed area.

Adverse Impacts

• Construction of a new visitor center and associated parking (with potential impacts of up to 5 acres) in the vicinity of Tioga Pass would impact lodgepole pine forests and wet and dry subalpine meadows. Dry meadows and lodgepole forests would be affected by paving and addition of structures, utility lines, and trails, thus reducing both the size and continuity of these vegetation types and resulting in long-term, moderate, and adverse impacts. Wet meadows would also receive increased adverse impacts from radiating uses due to more human activity in the area. Impacts to wet meadows could be mitigated by more clearly defining trails leading to the Mt. Dana cross-country route and would most likely remain moderate (despite any mitigation) simply as a result of higher levels of human use in the area.

• Paved areas and structures would result in changes in drainage patterns, resulting in moderate adverse impacts. An increased number of visitors because of the new visitor center would increase the likelihood of additional firewood collection (causing loss of nutrient recycling), and more vehicles in the area would increase the chance of non-native plant establishment as a result of more trampling and denuded soils.

South Entrance

Vegetation at the South Entrance to Yosemite National Park is characterized by dense montane, mixed conifer forest dominated by a white fir overstory with subordinate sugar pine, Douglas-fir, ponderosa pine, and Jeffrey pine. Riparian vegetation occurs along ephemeral and perennial stream channels.

Continued degradation of these vegetation types would occur under Alternative 4. The impact of this alternative would be long-term, minor, and adverse because there would be some increase in vegetation loss and degradation as compared to the existing condition.

Adverse Impacts

• Increased parking and structures would further add to the habitat fragmentation of the area, with an increased loss of riparian vegetation caused by potentially filling drainages, and an increased loss of forest cover. The loss of riparian vegetation could be minimized by using existing old road and railroad corridors rather than creating new developed areas, resulting in minor, adverse impacts due to the small area that would be affected. Forests would be impacted by the loss of up to 5 acres of trees in a currently forested area. Additional impacts would occur from the expansion of the hazard tree management zone along the corridor and around new parking areas.

• An increase in paved areas, how long vehicles are parked, and levels of human use in the South Entrance area would increase the potential for introduction and establishment of non-native species through a higher level of road-edge maintenance, increased introduction of sand with potential weed seeds, and more people with seeds clinging to clothing and cars. Impacts would be moderate and adverse to riparian vegetation, and minor for forested areas.

• The increased human population would make reintroduction of fire into the South Landing area more problematic due to smoke and the presence of structures. These limitations could be minimized by designing the site to concentrate structures in as small an area as possible. Vegetated "islands" would also be minimized to allow management of adjacent vegetation with fire (minor).

CONCLUSION

In Yosemite Valley, California black oak woodlands would receive major, beneficial impacts by the removal of some structures within existing stands and the potential for restoration of large areas of former California black oak. Both meadow and riparian areas in the east Valley would also receive major, beneficial effects under Alternative 4 due to the removal of some facilities, the consolidation of others out of the Merced River floodplain, and an increased ability to restore large portions of the Valley to natural conditions. These benefits would be offset by moderate, adverse impacts from radiating effects to adjacent areas near Superintendent’s Bridge (proposed for removal) and in currently undeveloped areas in the west Valley. Upland forests in the west Valley would experience moderate, long-term, and adverse effects as a result of development of parking and circulation facilities at Taft Toe.

In the El Portal Administrative Site, long-term, moderate, and adverse effects would occur to the oak and upland communities due to new housing development and parking. Riparian areas would experience moderate, adverse effects from radiating impacts resulting from existing and increased human population.

Long-term, moderate, and adverse impacts on montane forests would occur at South Landing due to a loss of forest stand structure, continuity, and understory integrity. Lodgepole pine forests and subalpine meadows at Tioga Pass would also experience moderate, long-term, and adverse impacts as a result of trampling and a small area of habitat loss.

Long-term, minor, and adverse effects would occur in Foresta, at Big Oak Flat Entrance, at South Entrance, and at Badger Pass due to slightly increased radiating impacts from an increased human population, a higher chance of non-native species establishment, and a slightly greater fragmentation of vegetation.

The overall effect of Alternative 4 on vegetation would be minor, long-term, and beneficial based on the relatively large areas of high-value vegetation resources to be restored, the similarly large amount of adverse impacts occurring in non-highly valued resource vegetation types (uplands and other), and the moderate amount of new habitat fragmentation generated.

CUMULATIVE IMPACTS

The overall impacts of past, present, and reasonably foreseeable future projects on vegetation would be the same under Alternative 4 as is described for Alternative 1.

Increased human activity and related air quality degradation in the El Portal area and elsewhere could adversely affect ponderosa pine, Jeffrey pine, and other ozone-intolerant species. The National Park Service has operated an ozone monitoring station at Turtleback Dome for more than a decade to identify ozone trends in the Valley. Although cleaner burning vehicles and fuels should reduce the amount of ozone in the atmosphere in the future, cumulative effects to such plant species are expected to continue.

Other cumulative impacts to vegetation under Alternative 4 would include plant community fragmentation resulting from increased land development and potential continued introduction of non-native plant species. Cumulative impacts to riparian vegetation would also be expected due to development and other pressures along the narrow Valley floor adjacent to the Merced River.

Adverse impacts to upland vegetation under Alternative 4 would occur at South Landing, El Portal, Foresta, and at all entrance stations. These impacts, in conjunction with impacts to upland areas in Yosemite Valley (due to new development at Taft Toe) and a loss of forests over time to highly valued meadow, California black oak woodland, and riparian vegetation types, would constitute moderate overall impacts to upland communities as proposed in the Final Yosemite Valley Plan/SEIS. In conjunction with the areawide projects discussed for Alternative 1, actions proposed under Alternative 4 would result in a cumulative minor, adverse impact to upland vegetation because of the current extensive coverage of upland vegetation throughout the Sierra Nevada region.

Restoration actions proposed in Yosemite Valley and the removal of structures (decreasing habitat fragmentation) in some areas would result in more acres of restored California black oak woodland. The re-introduction of fire into tree stands adjacent to upland communities would also create additional acres of potential California black oak woodland. The loss of black, canyon live, blue, and valley oaks from construction in El Portal, however, would increase habitat fragmentation, but site planning to avoid large trees and designing landscapes to minimize irrigation impacts would help mitigate these actions. Small areas of talus live oak communities would be restored at Curry Village. In combination with reasonably foreseeable future actions, cumulative moderate, beneficial impacts to oaks would occur as a result of this project.

Alternative 4 calls for the implementation of a River Protection Overlay zone in Yosemite Valley, which would create long, linear sections of intact riparian vegetation following restoration efforts. The natural links with meadows would be restored, and large continuous meadow areas would be re-created throughout the east Valley. However, this alternative also, proposed additional multi-use paved trails, which often follow or cross riparian areas. Impacts could also occur to subalpine meadows at Tioga Pass. Thorough site planning could prevent impacts to riparian and meadow vegetation in these newly developed areas by avoidance, thus resulting in a cumulative moderate, beneficial impact to riparian and meadow vegetation. Therefore, the overall cumulative impact of Alternative 4 on vegetation, in conjunction with reasonably foreseeable future impacts, would be minor and beneficial.

This analysis describes impacts to wildlife in terms of changes to habitat, such as habitat loss or gain, degradation or enhancement, fragmentation or connectivity, amount of human disturbance, and potential for increased or decreased conditioning of wildlife. The Vegetation section provides detail (including acreage breakdowns) on the vegetation types that are related to the habitat types covered in this section: upland, California black oak woodland, meadow, riparian, and other. All but the upland and other habitat types are considered highly valued resources by the park because of their value to wildlife combined with other factors, such as scarcity on a regional basis and value as critical components in park ecosystems. General wildlife species associated with these habitat types are discussed in Chapter 3, Affected Environment, Wildlife; table 3-6 illustrates the connections between vegetation types and wildlife habitats. Rare, threatened, and endangered wildlife species are discussed in a separate section of this chapter.

Short-term impacts on wildlife would occur during construction or implementation of actions described in this section. Based on the mitigation measure that would be implemented during construction, all expected short-term impacts would be negligible.

Other impacts on wildlife and wildlife habitat generally would be characterized as long term for the actions reviewed under this alternative.

YOSEMITE VALLEY HABITAT

Habitat restoration would result in approximately 193 acres of restored or enhanced wildlife habitat within the Valley, of which 174 acres would be restored to highly valued resource habitat types. New or relocated development within existing wildlife habitat would result in approximately 102 acres of lost or degraded wildlife habitat, of which 88 acres would occur within upland or "other" habitat types within the Valley.

In restored habitat of all types, the resulting benefit to wildlife is highly dependent upon the size of the area restored and its connection or proximity to other natural or restored areas. Such benefit is also related to the proximity of the restored area to continued human activities and development. Larger restored areas of habitat tend to support a higher abundance and diversity of wildlife species and are less affected by human disturbance from adjacent development and uses. Connections within and among habitat types allow more natural wildlife movement, and access to food, cover, and reproduction sites necessary for all stages the life cycles of various species. Management of human use in areas adjacent to natural or restored areas can minimize disturbance that would degrade habitat quality, especially of sensitive habitats such as meadows and riparian. For example, signs and fencing could keep visitors away from sensitive habitats or wildlife species, and control of human food sources in developed areas could reduce conditioning of wildlife and minimize human/wildlife conflicts.

Upland Habitat

Approximately 94 acres of existing upland habitat would be developed under this alternative, approximately 19 acres would be restored, and an additional 75 acres would be converted to highly valued resource habitat types. The beneficial impacts to upland habitats would primarily be the result of increased connectivity of uplands with other habitats as well as enhancement of habitat structure in east Yosemite Valley. The adverse impacts to upland habitat would occur primarily as a result of habitat loss in west Yosemite Valley.

A summary of actions and impact intensities for Alternative 4 is provided in table 4-92. The adverse and beneficial impacts to upland habitat and associated wildlife species under Alternative 4 would generally be the same as those described for Alternative 2, with the following exceptions:

Development of a new Taft Toe facility for day-visitor parking and a transit/visitor center would remove approximately 53 acres of upland habitat (although only about one-third the number of parking spaces would be constructed at Taft Toe under Alternative 4, the affected area would be the same as in Alternative 3 to accommodate out-of-Valley shuttle buses). Development in this location would affect species such as ringtail, California spotted owl, and Gilbert’s skink; result in a high degree of habitat loss and human disturbance in the mid-Valley; and create a large element of habitat fragmentation. Noise, light, and increased human use radiating from the facility into adjacent habitats, including highly valued resource types, would affect their existing quality. Hazard tree mitigation would reduce local snag numbers, which could affect wildlife such as bats and woodpeckers.

The location of this facility at the foot of Cathedral Spires gully would place it in a corridor that may be used by wildlife moving into and out of the Valley, which could inhibit the movement of some species or lead to conflicts between humans and animals. Such conflicts could result in property damage, injuries, and conditioning of animals to human food sources in an area of the Valley where such incidents are now rare. Parking at Taft Toe, especially in the early morning or late evening, could lead to high levels of vehicle break-ins by conditioned black bears. General mitigation measures would be incorporated into the proposed parking areas to minimize impacts to wildlife, including restricting visitor access into adjacent sensitive habitats, providing information and enforcement to discourage wildlife feeding and encourage proper food storage, and providing adequate garbage services. Surface water runoff from parking areas would be collected and treated prior to its entering meadows or riparian areas to minimize pollution impacts on frogs and other species dependent upon aquatic habitat. Lighting would be designed to minimize illumination of surrounding areas. Despite these mitigation measures, impact of the Taft Toe facility on wildlife would be major and adverse.

• A new picnic area with grills would be established at Curry Orchard, creating a new area for human/wildlife conflicts. The removal of parking from the orchard under this alternative would reduce the conditioning of bears to food in vehicles, and reduce damage to vehicles. Picnicking in the orchard, however, would likely result in dangerous interactions between wildlife and humans, especially when the apple trees are fruiting, attracting large numbers of black bears, deer, and squirrels and resulting in moderate, adverse impacts.

California Black Oak Woodland Habitat

Approximately 7 acres of existing California black oak woodland habitat would be developed under this alternative and approximately 25 acres restored to this highly valued resource wildlife habitat. The beneficial impacts to California black oak woodland habitats and associated wildlife would primarily be the result of increased habitat size and connectivity with other habitats, and more natural habitat structure. The adverse impacts to California black oak woodland habitat would occur primarily as a result of habitat loss.

The adverse and beneficial impacts are generally the same as described under Alternative 2. The primary differences in actions from those described in Alternative 2 are discussed below. A summary of actions and impact intensities for Alternative 4 are provided in table 4-92. Beneficial impacts on California black oak woodland habitat would have corresponding beneficial effects on many species, including mule deer, acorn woodpeckers, squirrels, mice, great-horned owls, and a variety of small birds.

• The former gas station site and former bank building would be restored to California black oak woodland. Small patches of this highly valued resource would be restored. These areas, however, represent a relatively small portion of California black oak habitat in the Valley, and would have continued human disturbance from Yosemite Village at the bank building site, and Yosemite Lodge and Camp 4 (Sunnyside Campground) at the gas station site, which would limit their quality to wildlife. Therefore, the net gain in habitat value would be minor.

• Ahwahnee Row houses would be removed and the area restored to California black oak woodland and some meadow habitat. The forest/meadow edge would be restored, providing a high-value ecotone for wildlife. Flows from Indian Creek could be allowed to follow a more natural course, leading to improved meadow habitat and the formation of riparian habitats (both highly valued resources). Impact from domestic pets and non-native plants associated with current housing would be reduced. This restored habitat would be a relatively thin strip, and continued high levels of human use in adjacent areas would limit the value of this restoration to wildlife (to moderate, beneficial) by causing disturbance in the area.

• Superintendent’s House (Residence 1) would, as in Alternative 2, be removed, but a picnic area would be established in that location. While such development would leave the oak trees intact, much of the understory and ground vegetation would be removed to establish the picnic area, and subsequently, this area would be subject to human trampling. The picnic area would affect the quality of the habitat to wildlife by preventing the return of natural woodland structure, and regeneration of oaks would be adversely affected. The picnic area would become a new site for conditioning of wildlife to human food. Overall, this action would cause a minor, adverse impact.

| Table of Contents | Alternative 3 | Alternative 4 | Alternative 5 | Commitments of Resources | Uses/Productivity |
| Short-Long Term | Chapter 5 | Chapter 6 | Bibliography | Glossary | Acronyms/Abbreviations | Index |
| Part 1 | Part 2 | Part 3 | Part 4 |

Yosemite National Park Home Page http://www.nps.gov File created/updated Yosemite National Park Web Manager