| Table of Contents | Environmental Consequences | Alternative 1 | Alternative 2 |
| Part 1 | Part 2 | Part 3 | Part 4 |

The analysis of potential impacts from actions implemented under Alternative 1, the No Action Alternative is presented in this section.

This analysis assesses 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 potential 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, non-point source pollution from vehicles or recreational use).

YOSEMITE VALLEY HYDROLOGY

There are currently campsites, rustic lodging units, employee housing, stables, parking areas (e.g., Camp 6) and other facilities immediately adjacent to the Merced River and within its floodplain. This development, as well as roads through Stoneman, Ahwahnee, and Cook’s Meadow, would continue to adversely affect the river’s ability to develop natural meanders, change course, and maintain a natural floodplain because facilities often obstruct and divert natural river flows. Development immediately adjacent to the Merced River and within its floodplain would continue to represent long-term, adverse impacts to hydrology.

Man-made obstructions in the Merced River and its tributaries (e.g., the rock-rubble pile at Yosemite Creek), such as bridge abutments (e.g., Sugar Pine Bridge) and riprap that protect facilities (e.g., El Portal Road), would continue to constrict and alter water flows. All eleven bridges and assorted riprap in Yosemite Valley would continue to have a long-term, adverse impact to the river’s hydrology. See Vol. Ia, Chapter 3, Affected Environment, for a description of the bridges and their interaction with the Merced River.

Cascades Diversion Dam would continue to have a long-term, adverse impact to hydrology by impeding river flows.

Pedestrian use along the banks of the Merced River has resulted in soil compaction, erosion, and riparian vegetation loss or decline, with consequent bank instability. The ultimate effect of bank instability is unnatural erosion, unnatural sediment deposition into the river, and localized river widening. Local, long-term, adverse impacts to riverbank stability would continue to occur due to visitor access to the river in some locations.

The existing three structures at Ahwahnee Row that are located in the 100-year floodplain would continue to have a long-term, localized, adverse impact to floodplain values by impeding flood flow (particularly pooling in this area).

YOSEMITE VALLEY WATER QUALITY

Water quality throughout Yosemite National Park is considered to be good and generally above state and federal standards. An inventory of water quality data performed by the National Park Service indicated excellent conditions in many parts of the park, but some water quality degradation in areas of high visitor use (Williamson et al.1996a). The State of California considers the surface water quality of most park waters beneficial for wildlife habitat, freshwater habitat, non-contact recreation, canoeing, rafting, and water contact recreation.

Surface water draining over granitic bedrock in the park exhibits considerable variability in chemical composition, despite the relative homogeneity of bedrock chemistry. Surface water in most of the Merced River basin is very diluted (lacking in dissolved solids), making the ecosystem sensitive to human disturbances and pollution. Studies have indicated a presence of Giardia lamblia and fecal coliform in various surface waters throughout the park, thereby limiting direct consumption of surface water by humans (Williamson et al. 1996a).

Good water quality is critical for the survival and health of species associated with riparian and aquatic ecosystems. Water quality elements that affect aquatic ecosystems include water temperature, dissolved oxygen, suspended sediment, nutrients, and chemical pollutants. These elements interact in complex ways within aquatic systems to directly and indirectly influence patterns of growth, reproduction, and mobility of aquatic organisms. For example, sediment may not be directly lethal to fish, but sediment deposited on the streambed may disrupt the productivity and life cycles of fish and aquatic insects.

Existing parking areas and turnouts in areas such as Curry Orchard, Yosemite Falls, Stoneman Meadow, Bridalveil Falls area, El Capitan Meadow, and Cook’s Meadow would continue to be sources of non-point source pollution. Nutrients, turbidity and coliform would continue to enter the river from both National Park Service and concessioner stables. Recreational uses such as swimming and rafting would continue to be sources of non-point source pollution. These facilities and uses in and immediately adjacent to the Merced River would continue to have long-term, adverse impacts to water quality.

EL PORTAL HYDROLOGY AND WATER QUALITY

The existing flood control levee (hereafter, levee) in the Hennessey’s Ranch area is above the normal high water line and does not affect annual spring runoff, but would continue to redirect river flows during large flood events. The levee is designed to protect facilities located within the natural floodplain in this area, and was not overtopped by the January 1997 flood. The levee prevents floodwaters from depositing sediment in the area, disrupting the natural processes of the floodplain. The levee would continue to have adverse impacts to the hydrology and floodplain values of the Merced River in the vicinity of Hennessey’s Ranch.

Facilities and recreational use along the banks of the Merced River throughout El Portal have resulted in soil compaction, erosion, and decline or loss of riparian vegetation. The ultimate effect of bank instability by these mechanisms is unnatural sediment deposition into the river, and localized river widening, although riverbank instability is less severe in El Portal than in Yosemite Valley. Artificial bank stabilization mechanisms such as riprap would continue to restrict and divert river flows, especially larger flood flows, and displace riparian vegetation. In El Portal, localized, long-term, adverse impacts to hydrology would continue to occur within the floodplain under the No Action Alternative.

Almost all of the facilities in El Portal are in close proximity to the Merced River, including the gas station and bulk fuel storage facility, employee housing, the market and post office, and operational facilities at Railroad Flat. These facilities, and the concentration of residential and operational activity associated with them, would continue to adversely impact water quality by contributing to non-point source pollution. In particular, the bulk fuel storage facility has a regional, long-term, adverse impact to water quality due to the inherent risk of fuel release during large flood events.

WAWONA HYDROLOGY

At Wawona, there are a few facilities immediately adjacent to the South Fork Merced River and within the river’s floodplain: private homes, portions of the Pioneer Yosemite History Center (including the covered bridge), a small portion of the maintenance complex, and the Wawona Road vehicle bridges. These facilities, and the concentration of visitor and employee activity associated with them, would continue to adversely impact the hydrology of the area, including floodplain values.

WAWONA WATER QUALITY

There is substantial development at Wawona, some of which is immediately adjacent to the South Fork Merced River and Chilnualna Creek: employee housing, private houses, lodging at the Wawona Hotel and at the Redwood Cottages, a National Park Service maintenance yard, the Yosemite Pioneer History Center, etc. This development has a long-term, adverse impact to water quality by contributing to non-point source pollution.

HAZEL GREEN HYDROLOGY AND WATER QUALITY

Hazel Green is located near the headwaters of Bull Creek, which drains into the North Fork of the Merced River, and Hazel Green Creek, which drains into Crane Creek. The hydrology of Hazel Green Creek and surface water runoff are the only pertinent hydrologic processes. The area is undeveloped and there is currently no impact associated with development at the project site.

FORESTA HYDROLOGY AND WATER QUALITY

Foresta is located on the banks of Crane Creek. The hydrology of Crane Creek, a small wetland, and surface water runoff are the only pertinent hydrologic processes. Within this area there are residential houses, a corral, and an access road to the area, all of which contribute non-point source pollution to Crane Creek. Two bridges across Crane Creek alter the creek’s flow. The continuation of non-point source pollution to Crane Creek and the small wetland, and continued alterations of Crane Creek from the bridge would be a continuing, long-term, adverse impact.

SOUTH LANDING HYDROLOGY AND WATER QUALITY

South Landing has no significant hydrologic features, and surface water runoff is the only pertinent hydrologic process. The access road adversely impacts hydrology by diverting and concentrating water at several locations. The area is used to store materials and equipment and has been used as a firing range; these uses contribute to non-point source pollution, and adversely impact water quality.

HENNESS RIDGE HYDROLOGY AND WATER QUALITY

Henness Ridge has no significant hydrologic features, and surface water runoff is the only pertinent hydrologic process. There is a small, disturbed area at the site that would have continuing adverse impacts to water quality.

BADGER PASS HYDROLOGY AND WATER QUALITY

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 existing parking lot and structures associated with the ski area would continue to adversely impact water quality by contributing non-point source pollution.

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. The existing facilities at these entrance stations would continue to adversely impact water quality by contributing non-point source pollution.

CONCLUSION

Conditions and features that affect Merced River hydrology are characterized in table 4-8. Development within the Merced River floodplain would continue to represent long-term, adverse impacts to hydrology, floodplain values, and water quality. Bridges, including the Sugar Pine, Stoneman, Housekeeping, Ahwahnee, Superintendent’s, and Swinging, would have a long-term adverse impact to river hydrology and the natural formation of floodplains. Local, long-term, adverse impacts to riverbank stability would continue to occur due to visitor access to the river in some locations under the No Action Alternative. Non-point source pollution resulting from development and recreational use of the river would continue to be a long-term, adverse impact in both El Portal and Yosemite Valley. Impacts to hydrology and floodplain values and water quality in El Portal would be long-term, localized, and adverse due to the current configuration of the flood control levee and presence of a bulk fuel storage facility adjacent to the Merced River. In Hazel Green, Henness Ridge, Foresta, and Badger Pass, both localized and regional long-term, adverse impacts would occur relating to water quality and soil stability.

The net impact of the actions of this alternative relative to hydrology, floodplain values, and water quality would be long-term and adverse.

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 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)

• 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 [YARTS]), 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 to water resources through increased non-point source water pollution.

Reasonably foreseeable projects that could have a net adverse impact to 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 to water resources of past, present, and reasonably foreseeable future projects on the Merced River watershed would be related to removal of facilities from the river banks 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 to 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, adverse impact on water resources. The actions of this alternative, in combination with past, current, and reasonably foreseeable future projects would have a long-term, adverse impact on water resources.

This section identifies non-exempted facilities that would remain in the Merced River floodplain in Yosemite Valley, El Portal, and Wawona as a result of implementation of the No Action Alternative (table 4-9). This section also evaluates the current level of risk to human life and property associated with these properties during a flood event. The Water Resources section of this chapter addresses potential impacts to floodplain values and hydrology. All impacts on floodplains would be of long-term duration.

1. Development may be in or surrounded by the floodplain.

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 continued presence of the dam, and its risk of failure, would be a long-term, localized, adverse impact to human health and safety.

Concessioner Stable Area

Houses and tent cabins with a total of 49 employee beds at the concessioner stable, and the kennel would remain within the 100-year floodplain. However, because floods in this area are typically predictable, occupants of these facilities would have advance warning of potential flooding and would be able to safely evacuate. The risk to human life in this area is considered minimal.

Housekeeping Camp

The 248 housekeeping units would remain in the 100-year floodplain of the Merced River. These lodging units are not used during the winter flood season; therefore, the risk to human life is considered minimal. The risk of property damage occurring to these units during a flood event would, however, continue to exist.

Yosemite Village

A total of 17 employee beds, the concession headquarters, and 1 lodging unit at the Ahwahnee are in the 100-year floodplain of the Merced River. However, because floods in this area are typically predictable, occupants of these facilities would have advance warning of potential flooding, and would be able to safely evacuate. The risk to human life in this area would therefore continue to be minimal; however, the risk of damage to these facilities during a flood event would continue to exist.

Yosemite Lodge Area

Five motel buildings, overnight parking, the Wellness Center, and nearby custodial cabins at Yosemite Lodge would remain in the 100-year floodplain. The Superintendent’s House (Residence 1), across from the lodge would also remain within the 100-year floodplain. Flood events in this area are typically predictable. Occupants of these facilities would have advance warning of potential flooding, and would be able to safely evacuate. The risk to human life is thus considered minimal; however, the risk of damage to these facilities during a flood event would continue to exist.

EL PORTAL

Four houses would remain in the 100-year floodplain at Abbieville. A total of 36 employee beds at the El Portal Motor Inn cabins and El Portal Hotel would remain in the 100-year floodplain at the Village Center. Additional facilities at the Village Center that occur within the floodplain and would remain include the El Portal Hotel (Yosemite Institute office and housing), the bulk fuel facility, gas station, El Portal Market, and National Park Service offices and ranger station. At Railroad Flat, portions of the El Portal Warehouse complex would remain in the 100-year floodplain. Based on historic records, it would take at least 48 hours from the start of a rain event for the river to rise to a stage where it would cross Highway 140 in the vicinity of the Village Center, allowing time for safe evacuation. The risk to human life would thus be minimal; however, the risk of damage to the facilities during a flood event would continue to exist.

WAWONA

Portions of the Pioneer Yosemite History Center would remain in the floodplain. The Center is not occupied overnight and could easily be evacuated in the event of a flood. The risk to human life at the Center would thus be minimal; however, the risk of damage to the Center during a flood event would continue to exist.

CONCLUSION

Approximately 106 employee beds and 248 lodging units would remain within the Merced River’s 100-year floodplain (66 employee beds and 248 lodging units in Yosemite Valley and 40 employee beds in El Portal) in structures not designed for flooding. Additional facilities in Yosemite Valley that would remain within the floodplain include the kennel, Concession Headquarters, the Superintendent’s House (Residence 1), five Yosemite Lodge Motel buildings, overnight parking at Yosemite Lodge, and the Wellness Center and nearby custodial cabins. In El Portal, non-lodging facilities that would remain within the floodplain include the Yosemite Institute office, bulk fuel facility, gas station, El Portal Market, the ranger station and offices at the Village Center, and portions of the El Portal warehouse at Railroad Flat. Portions of the Pioneer Yosemite History Center in Wawona would remain within the floodplain. Flood events along the Merced River and South Fork are generally predictable, and occupants of these facilities would have advance warning of potential flooding, and would be able to safely evacuate. Therefore, the risk to human life is considered adverse but minimal. The risk of damage to these facilities during a flood event would continue, resulting in an adverse impact.

CUMULATIVE IMPACTS

The impacts of past, present, and reasonably foreseeable actions to flood hazard 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 effect the watershed 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 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. 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. There could be risks to life and safety associated with construction of the Resources Management Building at Railroad Flat. A Statement of Findings would be developed as part of the El Portal design concept process to provide an accurate description of flood hazards and identify necessary mitigation. In El Portal, potential overnight residents and hotel visitors would slowly increase from approximately 1,300 to about 1,600 beds because of the proposed 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 1 would be long-term and adverse, because overnight lodging/housing and facilities within the floodplain would remain and continue to pose flood-related risks to human safety and property. Effects associated with this alternative, in conjunction with past, present, and reasonably foreseeable future actions, could be long-term and adverse.

In the middle of the 19th century, Yosemite Valley encompassed vast palustrine emergent wetlands that extended in places from valley wall to valley wall (Heady and Ziuke 1978). Bands of palustrine forest and scrub shrub wetlands along tributaries and the banks of the Merced River meandered between these emergent wetlands. As early settlers arrived in the middle of the century, uses of the Valley changed from subsistence hunting and farming with the addition of agriculture and grazing in support of the early tourist trade. The vast wetlands in Yosemite National Park began to shrink in size as waters were diverted or drained to protect facilities, aid farming, and rid the Valley of mosquitoes.

Today, an extensive network of structures, roads, campgrounds, and utilities is found in the Valley. Modern infrastructure coexists with remnants from past management operations such as ditches in meadows and channeled creeks. Wetlands (as represented by acreage of meadow and riparian areas), have shrunk to less than half of the acreage that was present when C. F. Hoffman mapped Yosemite Valley and calculated meadow acreage in the 1860s (Hoffman 1866; NPS 1994e).

In El Portal, a highway, roads, an historic railroad grade, and structures were constructed in areas that impacted riverside wetlands. Wetlands at Foresta and Hazel Green have remained relatively unimpacted by development. A ski resort was built at Badger Pass, affecting wetlands on the lower slopes and flat areas. There are no wetlands in the areas proposed for development at South Landing, Henness Ridge, Wawona, or Big Oak Flat Entrance, and therefore, they are not discussed below.

SIZE

Yosemite Valley

The size of existing wetlands in Yosemite Valley is directly compromised by development in former wetlands, and indirectly by development that alters hydrologic flows that sustain wetlands. Heavy foot traffic also threatens the size of wetlands, particularly in parts of the east Valley along the Merced River.

The extent of existing development that lies in former wetlands in Yosemite Valley was estimated from historic photos and narratives, historic topographic maps (NPS 1921), and current soils maps (SCS, USDA 1991). Wetlands probably occurred in parts of Upper and Lower River Campgrounds, Yosemite Lodge, Yosemite Village, Housekeeping Camp, North Pines Campground, and Lower Pines Campground, and along Northside and Southside Drives. These developed areas do not currently meet the definition of a wetland because they do not retain characteristic wetland hydrology, soils, or vegetation.

Existing development that alters hydrologic flows connected to wetlands includes roads, channeled creeks and rivers, and ditched meadows. Existing roads bisect Bridalveil, El Capitan, Sentinel, Cook’s, Ahwahnee, Leidig, and Stoneman Meadows. Parts of Ribbon Creek, Yosemite Creek, Indian Creek and many other tributaries of the Merced River are channeled, often for relatively long stretches (Milestone 1978). Ditches were dug in the mid-1900s along roads to prevent visitors from driving on the meadows. Many are still maintained to protect road surfaces.

The Merced River has tripled in width since the early 1900s in parts of the east Valley. This impact on palustrine forest wetlands along the riverbank is a result of heavy foot traffic and subsequent loss of riparian vegetation that protected highly erodable riverbanks, and trapped sediments and organic matter.

The size of palustrine emergent wetlands in Yosemite Valley is diminishing due to encroachment by conifers, resulting in a type conversion to upland habitat. This is most likely due to water tables lowered by redirected hydrological flows, ditching, and roads; and a lack of burning by American Indians, as theorized by recent studies (NPS 1943; Reynolds 1959; Gibbons and Heady 1964; Anderson and Carpenter 1991). Lowered water tables create conditions that foster conifer invasion at a rate that is far beyond the natural range of variability (Wood 1975).

Under the No Action Alternative, palustrine forest and palustrine scrub shrub wetlands along the Merced River would continue to sustain heavy foot traffic through the campground area in the east Valley and the river would continue to widen. Remaining palustrine emergent wetlands in Yosemite Valley would remain at similar sizes due to on-going prescribed fire management actions. Existing development in potential wetlands would remain, including roads, campgrounds, and lodging. Under the No Action Alternative, these adverse impacts on the size of palustrine forest, palustrine scrub shrub, riverine, and palustrine emergent wetlands in Yosemite Valley would continue.

Out-of-Valley Areas

Negligible impacts on the size of wetlands in Foresta and Hazel Green would continue. The size of historic wetlands at Badger Pass would continue to be adversely affected by impacts radiating out from the ski resort. In El Portal, the highway, roads, and structures would remain in areas that adversely affect riverside wetland vegetation. Palustrine forest wetlands at South Entrance would continue to receive negligible impacts from the adjacent road.

INTEGRITY

Yosemite Valley

The wetland integrity in Yosemite Valley is degraded, particularly in terms of the proportion of non-native to native plant species in meadows, and a loss of vegetation along riverbanks in the campground area of the east Valley.

Deep-rooted non-native perennial grasses, which were historically cultivated for agricultural purposes, outcompete native plant species in drier parts of palustrine emergent wetlands. When water tables are sustained at normally high levels, native species are able to outcompete non-native plant species. Analysis of Yosemite Valley vegetation shows that 24% of Valley palustrine emergent wetlands (represented by meadows) are dominated by non-native vegetation and another 23% of these wetlands are in transition from native to non-native vegetation (NPS 1994e).

Palustrine forest, scrub shrub, and riverine wetlands in the Merced River channel are particularly degraded in the campground section of Yosemite Valley. In this area the river has widened considerably and created a warmer, shallower river without the variety of riffles and deep pools needed to sustain natural aquatic life. Riverside vegetation overhanging the main channel is absent in many locations, and does not contribute nutrients, organic matter, or shade to the riverine system.

Yosemite Valley is traversed by a series of roads and multi-use paved trails that can directly affect wetland integrity by:

• Converting productive wetlands to barren road surfaces

• Constraining and diverting surface and subsurface flows

• Dewatering wetlands

• Concentrating and accelerating runoff

• Creating a source of toxic pollution

• Intercepting groundwater flows (USFS 1996)

Roads can also indirectly affect wetland integrity by:

• Increasing or decreasing channel gradients and runoff velocities

• Accelerating soil erosion and the loss of soil nutrients

• Triggering site conversion from wetland plant species to upland species

• Impairing habitat suitability for wildlife

• Degrading water quality (USFS 1996)

Under the No Action Alternative, integrity of palustrine emergent wetlands would continue to degrade from non-native plant species and conifer encroachment. Wetlands along the Merced River and its tributaries would continue to be degraded by heavy recreation-related foot traffic. Roads would continue to bisect palustrine emergent wetlands and divert water traveling from upland habitats to the river and tributaries. Under the No Action Alternative, these adverse impacts on the integrity of wetlands in Yosemite Valley would continue.

Out-of-Valley Areas

Adverse impacts on the integrity of wetlands in El Portal, Foresta, South Entrance, and Hazel Green would continue due to non-native plant species encroachment, and as a result of existing road and paved trail impacts. The integrity of historic wetlands at Badger Pass would continue to be adversely affected by the ski resort.

CONNECTIVITY

Yosemite Valley

Palustrine forest wetlands that line the Merced River would continue to be fragmented by heavy foot traffic that degrades vegetation alongside campgrounds, rafting focal points, parking at Camp 6, roads, and at focal points such as Sentinel Beach Picnic Area. Connections between the Merced River and upland habitats would remain compromised by roads, structures, utilities, and water diversions. Connections along the Merced River corridor and between the river and upland habitats are important for wildlife travel and access to water. Under the No Action Alternative, adverse impacts on the connectivity of wetland habitats in Yosemite Valley would continue.

Out-of-Valley Areas

Adverse impacts on the connectivity of wetlands in Foresta, Tioga Pass Entrance, and Hazel Green would continue due to the existence of roads through these sites. The connectivity of historic wetlands at Badger Pass would continue to be adversely affected by the ski resort.

CONCLUSION

Under the No Action Alternative, the Merced River would continue to widen unnaturally in Yosemite Valley. This would foster a shallower river that would not contain a variety of riffles and pools, would not have a ready source of large woody debris, and would be subject to temperature extremes; factors that otherwise contribute to the health of the aquatic system. Palustrine wetland vegetation would remain severely degraded in the campground area of east Yosemite Valley. Facilities and infrastructure would remain, some of which directly impact former wetlands such as Upper and Lower River Campgrounds. Surface water flows that sustain wetlands would remain obstructed by roads and other development. These conditions would continue to have long-term adverse effects on the size, integrity, and connectivity of wetlands in Yosemite Valley.

Long-term adverse impacts on riverine, palustrine forest, and palustrine scrub shrub wetlands along the river in El Portal would continue due to the presence of roads and structures impeding natural water flows through old river channels and impacting river-edge vegetation. Adverse impacts to palustrine emergent wetlands at Badger Pass would continue as a result of radiating use of the meadow from the ski area and parking lot. Palustrine forest and scrub shrub wetlands in Foresta, Hazel Green, and South Entrance would continue to be adversely impacted by adjacent roads and non-native species encroachment. Wetlands at Tioga Pass would continue to receive negligible, adverse impacts from current levels of human use.

CUMULATIVE IMPACTS

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 also could increase knowledge of resources and recreational use. These plans 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 affect wetlands through zoning and management designed to protect the river system and adjacent wetlands, with long-term, major, beneficial impacts.

The Tuolumne Meadows Water and Wastewater Improvements (NPS) project and the Mariposa Creek Pedestrian/Bike Path (Mariposa Co.) project are in the early stages of planning. Until the scope and design of the 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 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 denuded riverbanks that were formerly palustrine forest and palustrine scrub shrub wetlands. The erosion control and restoration projects would have long-term, localized, 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. A palustrine scrub shrub wetland traverses the Hazel Green Ranch site and a palustrine emergent wetland exists in the center of this area. Proposed new development would not avoid the wetland corridor. The long-term direct impacts on wetlands would be adverse due to the relative rarity of undeveloped wetlands between 1,000 and 3,000 feet in elevation, and the relative importance of remaining wetland habitat throughout 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.

Regional and parkwide plans which could result in long-term, moderate, and beneficial cumulative impacts on wetlands are tempered by adverse impacts that include extensive infrastructure that diverts water away from wetlands in Yosemite Valley, the potential direct loss of wetland habitat at the Yosemite View Parcel Land Exchange, and other projects outside Yosemite National Park, and continued unnatural widening of the Merced River in the east Valley.

These areawide projects (as described in Vol. II, Appendix H), in conjunction with the impacts of the No Action Alternative, would have overall adverse impacts on wetlands in the area. All of these impacts would be long term. The potential for beneficial and adverse impacts to wetlands would be greater from projects occurring within the cumulative impact assessment area of the Sierra Nevada bioregion than from this alternative. Therefore, Alternative 1, in conjunction with other regional planning and development activities, would have a minor to moderate, adverse impact to wetlands due to the relative rarity of undeveloped wetlands in the Sierra Nevada.

The soils impact analysis is based on three integrated parameters: the size of the area affected, degree of previous disturbance, and soil resource type. Three soil resource types are defined in the Methodology section of this chapter: resilient soils (R), highly valued resource soils (HVR), and other soils not identified as resilient or highly valued resource soils (O).

The No Action Alternative is provided as the baseline condition by which all other alternatives are evaluated. Existing conditions and trends in land management are assumed to continue in the future. Further degradation of soil resources may occur as a result of continued human use and existing development in the area. The following discussion is provided to characterize these impacts.

YOSEMITE VALLEY

Approximately 407 acres of soil is currently affected by some level of previous disturbance. Of this acreage, 120 acres are highly valued resource soils and 217 acres are resilient soils. Acreages were calculated with the parameters used in the 1991 Yosemite Valley Soil Survey. Table 4-10 summarizes Yosemite Valley soil types and currently affected acreage. Affected acreage totals were rounded to the nearest acre. Some minor discrepancies between acreage in the text and table may occur due to rounding, differences in mapping sources, or because impacts were not mentioned in the text if they were small (less than 1 acre).

Adverse soil impacts would continue to be associated with existing structures, roads, trails, campgrounds, and parking facilities. Impacts would be primarily related to erosion, compaction, soil profile mixing, and soil removal. Soils associated with riparian areas, such as the Riverwash series, are susceptible to erosion. Generally, these soils are coarse textured and have little organic matter to provide structural integrity. Removal of vegetation in heavily traveled areas further reduces soil stability. Continued uncontrolled access to the river would result in further erosion and decreased bank stability.

Soils that have been excavated and/or covered by impervious surfaces such as roads, parking lots or buildings may lack typical physical, biological, and chemical properties. In Alternative 1, soil removal and profile mixing have occurred in localized areas for building, road, and trail construction activities. For example, the Miwok complex soil type will continue to be impacted by buildings and parking lots at the general maintenance area and Curry Village.

Adverse impacts to soils resulting from current uses have lasted for several decades at existing building and road sites. Most of the impacts are long term. Erosion impacts may be temporary to long term, depending on the location and potential for renewal through sedimentation associated with flooding. For example, adverse impacts to floodplain soils are ameliorated over time by renewal during flood events.

Adverse impacts would continue on a mix of resilient and highly valued resource soil series. For example, the Lower Pines Campground would continue to affect highly valued resource soils (e.g., El Capitan) as a result of compaction and erosion impacts; likewise the Upper and Lower River Campgrounds would continue to affect resilient soils of the Miwok complex. These resilient soil types have physical attributes that generally support current land-use practices. However, hydric and other highly valued resource soils would continue to be disturbed by current land-use practices, including 101 Riverwash along the Merced River above Stoneman Meadow and 104 Aquandic Humaquepts at the Tenaya Creek/Merced River confluence. Although the area of disturbance is fairly localized, these soils cover much less acreage than the resilient soil types.

The current soil impacts within Yosemite Valley would remain unchanged under Alternative 1. The continued impacts associated with Alternative 1 would be adverse and long-term.

Soil impacts for seven areas or activities are characterized below. These conditions would continue under the No Action Alternative.

Curry Village

• Scattered visitor parking continues

• Current use of lodging units, campgrounds, ice rink, and area trails continues

The current affected acreage is approximately 49 acres (HVR = 0, R = 20, O = 29).

Yosemite Lodge

• Yosemite Creek human built rubble pile remains

• Lodge cabins are neither rebuilt nor restored

• Scattered visitor, staff, and employee parking continues

• Use of lodging units, area roads, parking lots, and trails continues

The current affected acreage is approximately 79 acres (HVR = 8, R = 69, O = 2).

Yosemite Village

• Use of current road through Cook’s Meadow

• Camp 6 continues as parking area

• Current use of Church Bowl picnic area continues

• Current concession uses in Yosemite Village center remain

• All housing units remain

The current affected acreage is approximately 105 acres (HVR = 16, R = 60, O = 29).

West Valley

Current land use remains at El Capitan Picnic Area, Cathedral Beach Picnic Area, and Bridalveil Fall. The current affected acreage is approximately 6 acres (HVR = 3, R = 2, O = 1).

Campgrounds

Use of current campgrounds continues at all sites. The current affected acreage is approximately 171 acres (HVR = 94, R = 65, O = 12).

Roads and Trails

Soils that have a seasonally high water table are susceptible to localized compaction. Existing roads and trails on soils such as the El Capitan and Leidig series have altered subsurface flow of groundwater, due to soil removal and compaction.

OUT-OF-VALLEY AREAS

The current development impacts within out-of-Valley areas would continue and remain unchanged under Alternative 1. The impacts would continue to be adverse and long term, because there would be no measurable change to existing baseline conditions.

CONCLUSION

Current visitor services and facilities within Yosemite Valley affect approximately 400 of the 3,555 acres of land area in the Valley. Further degradation of soil resources resulting from visitor use would continue. Impacts currently occur to several highly valued resource soils. Although these impacts may be ameliorated over time through restoration and visitor use access restrictions, the implementation of such restrictions would not be comprehensive. Thus the impacts are likely to remain over an extended period of time. The sum of all impacts resulting from current land use would have a long-term, adverse impact on existing soil resources.

CUMULATIVE IMPACTS

Since soil types vary by geographical location, actions outside Yosemite National Park generally do not impact the same soil types as those found within the Valley. Therefore, other present and reasonably foreseeable future projects considered to possibly have a cumulative impact on soils described in the Final Yosemite Valley Plan/SEIS must occur in the park or in proximity to the park. For purposes of this evaluation, projects within five miles of the park were considered to have a potential effect on soil types consistent with those found in the park. These projects include:

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

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

• Evergreen Lodge Expansion (Tuolumne Co.)

• Evergreen Road Improvements (Multi-agency, see Appendix H)

• Yosemite West Rezone for 55 Acres (Mariposa Co.)

• Tuolumne Meadows Development Concept Plan (NPS)

• Tuolumne Meadows Water and Wastewater Improvements (NPS)

• Hodgdon Meadow Campground Rehabilitation (NPS)

• Hodgdon Meadow Water and Wastewater Treatment Improvements (NPS)

Each of the above projects has the potential to produce further soil disturbances. These disturbances would include erosion and compaction associated with development, such as the expansion of the Evergreen Lodge and Hotels in El Portal. Projects in Tuolumne Meadows may impact highly valued resource soils that are susceptible to erosion. While projects such as the sewer line rehabilitation may have beneficial effects on water resources, their effect on soils would generally be adverse due to soil mixing, compaction, and erosion. Overall, the projects located outside of the park that may have cumulative impacts are small in scope, as compared to the total area of the region. Additionally, the impacts associated with those projects would be minimized through the use of Best Management Practices as required by local, state, and federal regulations.

As described above, impacts to soils under Alternative 1 would consist of a continuation of adverse effects associated with existing development and visitor activities in Yosemite Valley. No specific actions are proposed beyond current land management practices. Consequently, the cumulative impacts that would result from the combination of Alternative 1, as well as the other past, present, and reasonably foreseeable future projects, would continue to be long term and adverse.

YOSEMITE VALLEY

The Valley vegetation can be assembled into five general groups or types: upland, California black oak, meadow, riparian, and other (NPS 1994e). The other type includes miscellaneous non-native vegetation such as apple orchards and lawns, as well as bare ground and river channel. The Valley includes approximately 3,555 acres, of which approximately 70% is classified as upland, 5% as California black oak, 11% as riparian, 8% as meadow, and 6% as other.

Upland Communities

The majority of Valley vegetation falls under the upland vegetation type. Most of this has been disturbed to some extent by humans in the past; approximately 10% of upland acreage is heavily disturbed by past development of roads, facilities or structures, and frequent human activities. This category includes ten different subtypes of mixed conifers and canyon live oaks. Alternative 1 would provide no comprehensive approach to improvements, restoration, or management of these previously disturbed uplands or adjacent communities, resulting in continued and long-term degradation.

Size and Continuity

The size and extent of uplands in the Yosemite Lodge, Yosemite Village, and campground areas are unnaturally large due to lack of fire and modified hydrology, which has resulted in the encroachment of conifers into former meadows, riparian areas, and oak woodlands. This would continue under Alternative 1 due to the National Park Service’s inability to manage trees by prescribed fire within and around developed areas. Impacts would also continue where fill material was used to raise the level of the ground surface to provide drier sites for development (Camp 6 and the former Upper and Lower River Campgrounds). These upland communities would continue to expand and become more continuous through the Valley as existing and newly established conifers dry out soils, and woody debris and duff accumulate, gradually raising and drying the underlying substrate over time.

The unnaturally dense stands of incense-cedar and ponderosa pine would continue to contribute to the spread of annosus root rot through many of the developed areas in the east Valley (such as at Camp 4 [Sunnyside Campground], Yosemite Lodge, and Upper and Lower River Campgrounds area). Additionally, annosus root rot would continue to spread through the more open areas in the west Valley (such as Taft Toe and the vicinity of the old El Capitan picnic area), leading to continued high levels of management effort to remove hazard trees (dead or dying trees) from developed sites and road corridors.

Canyon live oak communities would continue to be impacted by housing and development at the Curry and Yosemite Village areas, while communities in the west Valley would continue to function naturally (albeit with higher than normal fuel loads) because of the lack of change in infrastructure, transportation routes, and trail systems.

Natural Structure, Diversity, and Productivity

A forest community’s diversity and productivity are directly related to the integrity of its structure (overstory, understory, and ground layers). The natural structure of the developed and disturbed upland communities in the Valley has been severely degraded due to lack of fire, resulting in an increasingly dense overgrown understory and a shift in species composition over time to more shade-tolerant coniferous species such as white fir, Douglas-fir, and incense-cedar. Therefore, under Alternative 1, the understory integrity, diversity, and overall productivity would continue to be impacted by a lack of native understory and lack of regeneration due to trampling in developed zones. Two examples where no action is considered a continued adverse impact are:

• Yellow Pine Campground and Sentinel Beach, formerly known for outstandingly large individual ponderosa pines, would continue to sustain a mixture of coniferous species in dense stands that would not facilitate re-establishment of the natural large individuals found there historically. This would be a direct result of the lack of prescribed fire and lack of ability to manage for more naturally open characteristics.

• Small portions of canyon live oak communities in the east Valley at the Upper Tecoya housing area would continue to lack a natural understory structure because of the continued existence of housing, with its associated trampling, landscaping, and non-native plant encroachment.

Continued degradation of this upland vegetation type would occur under the No Action Alternative and impacts would continue to be long-term and adverse, as there would be no measurable change from the existing condition.

California Black Oak Communities

Approximately 20 acres of the California black oak vegetation type have been heavily disturbed by past actions. Under the No Action Alternative, degradation would continue within those developed/disturbed areas of California black oak. The following describes the current condition of California black oak communities in the Valley.

Size and Continuity

• Existing stands would continue to be fragmented throughout the east Valley by development, roads, and encroaching conifers.

• Stands in the west Valley would continue to decline in size because of conifer encroachment and changes in hydrology resulting from the presence of roads. For example, Northside Drive impedes natural cross-slope drainage from Ribbon Fall to the Merced River, impounding water on the north side of the road. This unnaturally moist area encourages armillaria root rot in the remaining large trees at this site, causing tree failure either through collapse or increased susceptibility to other diseases. As a result, continuity of the California black oak canopy does not exist, and regeneration is not occurring at this site.

• Stands would continue to be impacted by summer irrigation in housing and landscaped areas (including the National Park Service historic housing district and landscaped areas surrounding The Ahwahnee), leading to further permanent loss of California California black oaks from mortality caused by armillaria root rot and lack of regeneration from armillaria and trampling.

• The continued inability to manage California black oak stands through prescribed fire (due to the presence of infrastructure) would continue to support mistletoe infestations and large infestations of oak galls. Lack of fire results in reduced nutrient cycling, which leads to tree stress and mortality of mature trees.

• The ability of the National Park Service to enhance California black oak woodlands would continue to be hampered by development and infrastructure through all developed California black oak areas of the Valley. Efforts to re-establish oak woodlands would continue to be done on a site-by-site basis rather than a holistic Valley wide basis.

Natural Structure, Diversity, and Productivity

• In developed areas, California black oak woodlands would continue to have little to no regeneration due to trampling, landscaping with irrigation, and other stresses, which increase the susceptibility of both young and old trees to armillaria root rot.

• Throughout the Valley, understory integrity would continue to be impacted by non-natives and/or lack of native vegetation as a result of paving, structures, and trampling.

• Continued loss of overstory trees to disease and the inability to manage the area through prescribed fire would continue to lead to an overall decline of California black oak in the Valley, with a loss of productivity and integrity for wildlife habitat.

• Due to the decline in California black oaks from lack of fire and alteration in drainages, other components of California black oak communities, such as deer grass (an important ethnographic resource), would continue to decline.

• Woodlands west of Curry Village would continue to be relatively unimpacted by human activities. However, the lack of fire would allow continued encroachment by conifers, leading to a gradual shift from a California black oak-dominated community to a mixed conifer California black oak community that is more common (thus less highly valued) in the Valley.

• The California black oak stand at the base of Bridalveil Fall would continue to be actively restored, as would stands at the Yosemite Valley elementary school, near The Ahwahnee, and along the Merced River in river restoration sites.

Continued degradation of California black oak communities would occur under the No Action Alternative, and impacts would continue to be long-term and adverse, as there would be no measurable improvement from the existing condition.

Meadow Communities

Approximately 8% of Valley vegetation falls in the meadow vegetation type (NPS 1994e). Many historic meadows have been converted to upland vegetation types or no longer exhibit meadow characteristics due to development. The following describes the current condition of meadow communities within the Valley.

Size and Continuity

• Meadow size would continue to gradually decrease in all meadows because of conifer encroachment, loss of natural drainage patterns because roads, bike paths with inadequate culverts, and river diversions (e.g., channelization of the confluence of Yosemite Creek with the Merced River).

• Continuity would continue to be disrupted because of fingers of conifers following raised portions of land along roadways and the bike path from Yosemite Lodge to Swinging Bridge.

• Areas of former meadow at the Upper and Lower River Campgrounds area; Northside Drive where it goes through Ahwahnee Meadow; portions of Lower Pines Campground; and roads through Sentinel Meadow and Cook’s Meadow would continue to either be altered or non-existent. These conditions are the result of raised road alignments, buried meadow soils where fill was added to raise land to increase suitability for development, and dominance by non-native herbaceous species due to altered soil and hydrologic conditions.

• Connectedness of meadows to riparian and wetland areas would continue to be cut off by roads and bike paths. Connectedness of meadow systems through the Valley would continue to be minimal at best due to unnaturally large areas of conifers between meadows and loss of oxbow and cutoff channels (see Glossary) which would have provided links from meadow to meadow.

Natural Structure, Diversity, and Productivity

• Meadows in the Valley would continue to have decreased integrity due to the presence of non-native plants and the introduction of stormwater runoff contaminants from adjacent roads, parking, and lodging.

• Drainage alterations, channelization and diversion of water away from these meadows, and ditches within meadows would continue to keep remaining meadows unnaturally dry. This would encourage invasion of drier areas by non-native plant species, with a loss of native diversity and a potential loss of productivity resulting from changes in species, food for wildlife, and cover.

• Meadows would continue to be maintained with prescribed fire; however, an inability to restore connections to river and upland areas because of continued development would continue to decrease overall meadow productivity.

Continued degradation of meadow communities would occur under the No Action Alternative. Impacts of this alternative would continue to be long-term and adverse, as there would be no measurable improvement from the existing condition.

Riparian Communities

Approximately 11% of Valley vegetation is within the riparian vegetation type (NPS 1994e). The impacts that would result from the No Action Alternative are listed by their effects on size and continuity of the community as well as the natural structure, diversity, and productivity.

Size and Continuity

• The riparian areas along ephemeral drainages and the Merced River through the Yosemite Lodge area and campgrounds would continue to be nearly non-existent due to the level of development, uncontrolled trampling, paving, and roads.

• Riparian zones along the Merced River and Yosemite Creek would continue to be lost by trampling as a result of undirected use of the river edge through the campgrounds and at Yosemite Lodge. This would result in discontinuous, narrow bands of riparian vegetation disrupted by long stretches of denuded and eroding riverbank, with little or no connection with either upland or meadow vegetation.

• Retention of bridges (Sugar Pine, Ahwahnee, Stoneman, Housekeeping, and Superintendent’s) and riprap would continue to cause unnatural hydrologic stress on upstream and downstream riparian areas, resulting in continued loss of riparian vegetation over time.

Natural Structure, Diversity, and Productivity

• Structure of riparian areas would continue to be impacted by encroaching conifers (along the Merced River, Yosemite Creek, and ephemeral drainages) and non-native plant species (Himalayan blackberry and foxglove along riverbanks).

• Narrow bands of existing riparian vegetation would continue to be prevented from expanding and reproducing because of existing development (bike paths, roads, and present structures) and partially removed structures (such as the old Eagle Creek and Bridalveil wastewater treatment plants), which continue to impact areas near the Merced River’s edge.

Continued degradation of riparian communities would occur under the No Action Alternative. Impacts of this alternative would continue to be long-term and adverse, as there would be no measurable improvement from the existing condition.

Other Communities

Approximately 6% of Valley vegetation is classified as "Other," which includes orchards, bare ground, and watered lawn. These areas have been modified to the extent that they no longer represent characteristics of a natural vegetation community. River channels, which lack perennial vegetation, are also included in this category. Specifically, these areas either remain unvegetated due to natural processes (surface river meandering) or human caused processes (human trampling), or represent "cultivated" vegetation types and thus do not fall within the primary Valley vegetation types. Under this alternative, these areas would remain as they currently exist within the Valley.

Impacts under this alternative would be long-term and negligible, as there would continue to be no measurable change from the existing condition.

OUT-OF-VALLEY AREAS

The following describes the impacts of the No Action Alternative on current conditions in each of the out-of-Valley areas. No actions would be taken in these areas under this alternative. Plant communities within the out-of-Valley areas do not directly relate to the grouped vegetation types defined for the Valley because of elevation, terrain, and plant composition differences. Therefore, plant communities in out-of-Valley areas are described separately from Valley vegetation types.

El Portal

As described in Vol. Ia, Chapter 3, the vegetation types found in the El Portal area of potential impact include canyon live oak (a type of upland) and riparian types; however, the plant composition of these types varies from those of the Valley. Meadow and California black oak types are not represented here.

Oak Communities

The existing oak stands would continue to decrease in size and continuity. The natural structure, diversity, and productivity would continue to be affected by the presence of non-native plant species, lack of natural fire and fire frequencies, and the current level of impact from development. Prescribed burning and mechanical removal of vegetation surrounding El Portal would continue to maintain semi-natural stands of oaks around developed areas by promoting oak regeneration with reduction of competing vegetation.

Continued degradation of this vegetation type would occur under the No Action Alternative. Impacts of this alternative would be long-term and adverse, as there would continue to be no measurable improvement from the existing condition.

Riparian Communities

• Riparian areas would continue to receive minor negative impacts from current development and use levels, with fluctuating continuity from cyclic flood scour and regeneration.

• The size of riparian areas would continue to be impacted by developments, including the Highway 140 corridor (managed by California Department of Transportation) and hotels and other development at Parkline, with continued decline in size (both length along the river and width from water edge up to the bank edge).

• Impacts from non-native plant species, including Himalayan blackberry and English ivy, would continue to inhibit regeneration of native riparian trees, shrubs, and especially herbaceous species.

• 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 the 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.

• Riparian areas immediately downstream of the Parkline development would continue to remain intact and highly functional, with minimal impacts from non-native plant species, human use, and trampling.

Continued degradation of this vegetation type would occur under the No Action Alternative, and impacts would be long-term and adverse, as there would continue to be no measurable improvement from the existing condition.

Foresta

The areas being considered for development in Foresta are dominated by whiteleaf manzanita/deerbrush associated with cheatgrass (in half the areas) and mesic red willow (in the other areas).

Size and Continuity

• Vegetation would continue to regenerate as it has since the severe A-Rock Fire of 1990.

• Fuels management work (prescribed fire and mechanical manipulation) would continue to facilitate a continuous and sustainable vegetative cover over the Foresta basin–a cover that is resilient enough to respond favorably to the frequent low-intensity fires that naturally move through the Foresta area.

• Private inholdings would continue to create small gaps in the otherwise continuous cover of the basin. The limited uses of areas such as Big Meadow would result in no change in either size or continuity of the riparian or meadow communities in and around Foresta.

Natural Structure, Diversity, and Productivity

• Fuels management work (prescribed fire and mechanical manipulation) would continue to facilitate a more natural (pre-exclusion of natural fire, pre-A-Rock Fire) stand structure in the Foresta basin, with priority placed on zones surrounding the developed areas.

• Productivity of the area would continue to change as stand structure changes with regeneration. Vegetation would continue to trend toward an open ponderosa pine/California black oak community, with meadows and riparian areas where they can be supported by suitable water supply and soils.

• 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 continue to occur, with associated management efforts to contain and control (and eventually eradicate) these species.

The vegetation types in the Foresta area would continue to improve as non-native plant species are controlled and/or removed and native vegetation cover becomes more well established. There would continue to be no measurable change to the existing condition, therefore, long-term impacts would continue to be beneficial.

South Landing

The vegetation found within the area of potential development in South Landing includes a ponderosa pine/incense-cedar type with sugar pine, and greenleaf manzanita (montane mixed coniferous forest and montane chaparral).

Size and Continuity

• Montane chaparral and montane mixed coniferous forest communities would continue to be disrupted by the maintenance of existing open areas remaining from old road and railroad corridors through the site as well as old staging areas remaining from construction of the Big Oak Flat Road in the 1960s. Disruption of these communities would also continue as a result of National Park Service activities in the vicinity of South Landing, including use of the area as storage for old equipment, a firing range for law enforcement staff, and a stockpile area for materials (such as sand, gravel, rock, and wood) for various ongoing projects and routine maintenance needs.

• Use of the area (for current activities) would require the continued management of hazard trees along the dirt road corridors and around the landing and firing range sites, further impacting the regeneration of this forest since it was clear-cut in the 1920s (prior to inclusion within Yosemite National Park) and impacted by road construction in the 1960s.

Natural Structure, Diversity, and Productivity

• National Park Service activities in the South Landing area would prevent the area from being managed with natural processes such as fire, thus continuing to impact the natural structure and promote an overly dense forest structure.

• 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). This condition would continue to affect the productivity and natural diversity of the South Landing sugar pine area as well as adjacent stands.

• Continued use of the site, including ground disturbance and importation of materials from outside the park, would continue the potential for introduction and establishment of non-native plant species at this site.

Continued degradation of native vegetation communities would occur in the South Landing area under the No Action Alternative. Impacts as a result of this alternative would be long-term and adverse because there would continue to be no measurable improvement from existing conditions.

Badger Pass

The vegetation found within the area of potential development at Badger Pass includes white and red fir (upper montane forest), meadow, and riparian communities.

Size and Continuity

• The upper montane coniferous forest community would continue to be dissected by the road, parking lots, and ski runs at the Badger Pass facility, with the continued management of hazard trees and removal of dead trees from the ski slopes.

• The montane meadow adjacent to the ski lodge would continue to be impacted by existing ski area structures, including the lodge, ski shop, and ski lifts. Impacts from the No Action Alternative would remain the same as existing impacts.

Natural Structure, Diversity, and Productivity

• The structure of the forest would continue to be manipulated to facilitate maintenance of the ski area, and natural fire events would continue to be controlled in the Badger Pass area to protect the existing structures. This would result in continued development of an overly dense understory with higher-than-normal fuel loads.

• Summer ski area maintenance activities would continue to disturb soil in and around the ski area (on dirt access roads leading to the top of the ski area, hazard tree removal, etc.), continuing to make the Badger Pass area susceptible to invasion by non-native species.

• Riparian areas downslope of the montane meadow would continue to be isolated because of the presence of access roads and parking lots, thus reducing overall productivity of the area.

Continued degradation of vegetation communities in the Badger Pass area would occur under the No Action Alternative and impacts would be long-term and adverse because existing conditions would not measurably improve.

Henness Ridge

Vegetation in the Henness Ridge area consists of a fairly intact canopy of montane mixed conifer forest with white fir, incense-cedar, and sugar pine.

Size and Continuity

• Existing conditions (a nearly homogenous coniferous forest community) would continue under the No Action Alternative, with small intrusions into the understory from past and currently used roads and a sand shed.

Natural Structure, Diversity, and Productivity

• Due to the relatively undisturbed nature of this area, natural structure, diversity, and productivity would remain the same (intact and relatively productive).

The continuity and structure of vegetation types in the Henness Ridge area would continue to receive minor intrusions under the No Action Alternative, with negligible impacts because any change from existing conditions would be immeasurable.

Hazel Green

Vegetation in the area of the potential parking and road development at Hazel Green is dominated by a mature white fir/sugar pine/red fir forest, with smaller riparian corridors along the headwaters of Hazel Green Creek.

Size and Continuity

• The white fir/sugar pine/red fir forest would continue to be bisected by the Big Oak Flat Road.

• Hazard tree management would continue to require the removal of dying and dead trees that are in danger of falling on the road. As a result, gaps in the forest canopy along the road would be more frequent due to the more rapid removal of overstory snags than would occur under natural conditions. Other areas would remain fairly intact, with natural gaps in the overstory canopy.

• The continuity of the riparian vegetation at the headwaters of Hazel Green Creek would continue to be broken by Big Oak Flat Road and ongoing road-edge maintenance activities.

Natural Structure, Diversity, and Productivity

• Stands of sugar pine in this area are somewhat affected by white pine blister rust, this would continue to affect the productivity and natural diversity of these stands as well as adjacent stands.

Continued degradation of these vegetation types in the Hazel Green area would occur under the No Action Alternative. Impacts resulting from this alternative would be long-term and adverse, as there would continue to be no measurable improvement from existing conditions.

Wawona

The dominant vegetation in the potential new housing area in Wawona consists of a lower mixed conifer forest of ponderosa pine, incense-cedar, sugar pine, white fir, and Douglas-fir, with occasional California black oaks. The area proposed for development is one of the last remaining undeveloped stretches along the South Fork Merced River through Wawona.

Size and Continuity

• The mixed conifer forest would continue to be bisected by Forest Drive, with some loss of continuity in the understory and overstory from this fairly narrow road.

• The mixed conifer forest would continue to provide a buffer between the road and housing development and the designated Wilderness boundary uphill and to the south.

Natural Structure, Diversity, and Productivity

• Stand structure would continue to be managed through a combination of mechanical thinning and prescribed burning.

• The Wawona area would continue to experience some impact from non-native plant species in areas disturbed by pile burning or hazard tree removal.

The impacts of Alternative 1 in the Wawona area would be long-term and negligible because there would continue to be no measurable change from the existing condition.

Big Oak Flat Entrance

Vegetation around the existing Big Oak Flat Entrance Station is dominated by a white fir/sugar pine/red fir forest and ponderosa pine/incense-cedar with sugar pine.

Size and Continuity

• The coniferous forests would continue to be bisected by the road, parking lots, and other facilities at the entrance station.

Natural Structure, Diversity, and Productivity

• Continued use of the site, with road maintenance activities and large numbers of vehicles, would continue to provide a source for the establishment of non-native plant species.

• Hazard tree management would continue to require the removal of dying and dead trees that are in danger of falling on the road. Removal of the trees would create more frequent gaps in the forest canopy than would occur naturally.

• Natural fire events would continue to be controlled in the Big Oak Flat entrance area to protect the existing structures, resulting in continued development of an overly dense forest understory with higher-than-normal fuel loads.

Continued degradation of the forest types in the Big Oak Flat entrance area would occur under the No Action Alternative. Impacts as a result of this alternative would continue to be long-term and adverse because the existing condition would not measurably improve.

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.

Size and Continuity

• Impacts would continue to occur to vegetation at Tioga Pass due to current development. Parking areas adjacent to the entrance station and at trailheads for Mt. Dana and Gaylor Lakes would continue to encourage radiating impacts to all three plant communities, thus decreasing their continuity. This impact would be long-term and adverse. Existing social trails around the tarns and heading toward Mt. Dana would continue to affect dry and wet meadow communities. A lack of clearly identified paths leading to the restrooms at the Gaylor Lakes trailhead parking lot would continue to encourage the use of existing social trails as well as the establishment of new social trails. These trails break up the continuity of vegetation cover, create unnatural openings by trampling paths through mat-forming plants, and break up and divert surface water flows. Gullies are created where water is unnaturally concentrated, and barren areas are created where water is diverted away.

Natural Structure, Diversity, and Productivity

• The function of all plant communities would continue to be adversely impacted by the presence of the road, parking lots, and other impediments to natural water flow and soil saturation. Continued collection of firewood in the lodgepole pine forest understory adjacent to parking areas would reduce the nutrient input of woody debris, leading to continued long-term, adverse impacts to this plant community. A risk of the establishment of non-native plant species in the vicinity of Tioga Pass would continue as a result of the current numbers of vehicles with the potential to carry seeds in from other areas, numbers of people (with mud on shoes and seeds on clothing and gear), and ground disturbance from social and established trails.

The continued degradation of vegetation types in the Tioga Pass area would occur under the No Action Alternative. Impacts resulting from this alternative would continue to be long-term and adverse, as there would be no measurable improvement from the existing condition.

South Entrance

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

Size and Continuity

• The continuity of vegetation at the South Entrance is currently fragmented by the presence of the main road, historic carriage road, historic railroad logging paths, and structures and parking at the entrance station. Sections of the Wawona Road lie on large cut and fill slopes up to 60 feet high. The cut slopes of decomposed granite and bedrock remain mostly unvegetated despite the passage of time since road construction. The road crosses a number of drainages, and fill was built up in these drainages to keep the road at grade. As a result, large dams of fill disrupt the continuity of riparian vegetation as streams pass under the road through culverts. This fragmentation would continue under this alternative, with long-term, adverse impacts to both montane forest and riparian communities.

Natural Structure, Diversity, and Productivity

• Road sanding, shoulder grading, and other road maintenance activities would continue to result in long-term, adverse impacts associated with the potential for establishment of non-native species along the corridor as well as within riparian areas adjacent and downslope of the road. However, fire could be reintroduced into the area (a long-term, beneficial impact) as part of the current fire management planning, resulting in improved understory structure occurring with the removal of doghair (unnaturally dense) thickets of seedlings and saplings.

Overall continued degradation of the vegetation types in the South Entrance area would occur under the No Action Alternative. Impacts resulting from this alternative would be long-term and adverse because there would continue to be little or no measurable improvement from existing conditions.

CONCLUSION

Under Alternative 1, no specific actions would be taken to change existing conditions. The existing condition of most Valley and out-of-Valley vegetation would continue to gradually degrade as a result of continued concentrated and radiating human use, and the ecological function (natural structure, diversity, and productivity) of plant communities would continue to be adversely affected by existing habitat fragmentation. The impact of this alternative would therefore be long-term and adverse.

CUMULATIVE IMPACTS

Upland Communities

Intact forests with trees of varying ages provide critical habitat for many wildlife species as well as other elements of biological diversity; perform important ecological functions; and provide inspirational, recreational, and cultural resources. National parks provide major concentrations of high-quality, late-successional forests in the Sierra Nevada and can provide an important reference point of pre-settlement conditions. However, the lower- and mid-montane conifer forests have been substantially altered. The areal extent of upland forests has greatly increased in the Valley since the 1860s as a result of the elimination of aboriginal burning and changes in hydrologic patterns. Overall stand density has increased in most lower- to mid-elevation forests due to lack of fire, while stand composition has been altered due to unnaturally large root rot populations and the establishment of white pine blister rust. Forests have been fragmented by the addition of roads, parking lots, and other infrastructure that has resulted in loss of either or both understory and overstory components, as well as the ability to regenerate. These patterns would continue under Alternative 1.

Increased human activity and related air quality degradation in the Valley and other montane areas 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 species are expected to continue.

Other cumulative impacts to vegetation include community fragmentation from increased land development and the potential for continued introduction of non-native plant species. Cumulative impacts to riparian vegetation also are expected because of development and other pressures along the narrow Valley floor, adjacent to the Merced River.

Other projects inside Yosemite National Park likely to affect upland communities (including South Entrance/Mariposa Grove site planning and various water and wastewater projects) would generally result in loss of individual trees with little overall impact to community function or continuity. The Yosemite Fire Management Plan Update (NPS) would reiterate the management goals and objectives for maintaining late-successional forests with management fires, resulting in major benefits to the ecology of these stands as structure is re-established over time. Other management plans, including U.S. Forest Service (USFS) wilderness plans in surrounding areas and the Sierra Nevada Framework for Conservation and Collaboration (USFS), would improve the possibility of a more comprehensive, ecosystem-based approach for managing the forests of the Sierra Nevada. Projects outside Yosemite National Park, including reforestation at A-Rock and Ackerson Complex Fire areas, Orange Crush Fuels Treatment Projects (USFS), and developments along all road corridors leading into the park, are expected to continue to directly remove trees (in the case of developments) or replant or manipulate forests for timber production rather than forest health, with resultant adverse effects.

Overall, the No Action Alternative, in conjunction with plans and projects outside of Yosemite National Park, would have little or no impacts to upland forests in the Yosemite region because of a balance between new management plans and continued fragmentation and lack of structure.

California Black Oak Communities

The Sierra Nevada region has 4.7 million acres of oak woodlands. Nearly 800,000 acres have been converted to other land uses over the past 40 years, including residential and industrial developments, rangeland clearing for the enhancement of forage production, and introductions of domestic livestock and non-native plant species. Past actions within the park that have impacted oak habitat include the inundation of Hetch Hetchy Valley by construction of O’Shaughnessy Dam, loss of integrity due to lack of aboriginal burning (leading to unnaturally dense coniferous stands with isolated, non-regenerating large oaks), damage and loss of oaks due to irrigation, and past and current construction activities.

Proposed and approved actions outside Yosemite National Park, including the expansion of Evergreen Lodge and expansion of housing in the Oakhurst/Bass Lake area would continue to cause a decline in oak woodlands. In addition, the expected population growth in the Yosemite region will contribute to further declines in oaks because of the use of oak for firewood to heat the increasing numbers of homes. Under the No Action Alternative, management of California black oaks in Yosemite Valley and Wawona would continue, with no direction towards managing intact woodlands or toward restoring integrity to existing highly impacted woodland and forest areas.

Alternative 1 would continue the trend of long-term, adverse impacts to oak woodlands throughout the Sierra Nevada region.

Meadow Communities

Meadow communities in the Sierra Nevada region have been dramatically reduced in area, vegetative complexity, and continuity in the past 150 years. Many of these areas, including Hetch Hetchy Valley, have been permanently inundated and impacted by past and present human activities (including grazing, plowing, drainage alteration to dry out soils, and intentional and accidental establishment of non-native plant species). The problem of noxious weeds and non-native invasive plant species threatens every aspect of ecosystem health and productivity in forests and on rangelands, and on both public and private lands. The increasingly devastating effects include the reduction of biological diversity, impacts to threatened and endangered species and wildlife habitat, the modification of vegetative successional stages, changes in fire and nutrient cycles, and degraded soil structure. Current levels of use in lower, montane, and subalpine meadows in the park continue to result in fragmented habitats, loss of productivity, and potential for accelerated conifer encroachment with loss of critical habitat. Development of the Silvertip Resort Village Project (Mariposa Co.) in Fish Camp and guest lodging and associated facilities at Hazel Green Ranch (Mariposa Co.) could affect remnant montane meadows at these sites.

Under the No Action Alternative, the piecemeal approach to restoration of meadow habitat in Yosemite Valley would continue. The pattern of human impacts to meadows throughout the region is also expected to continue. As with riparian zones, overall management direction for these areas, which encompass interconnected meadows and headwaters, would be provided by the Merced Wild and Scenic River Comprehensive Management Plan. Implementation of management plans for adjacent wilderness areas managed by the U.S. Forest Service would also likely benefit meadow vegetation through a more comprehensive and unified approach. Alternative 1, in conjunction with other plans and projects affecting meadow communities in and outside the park, would continue the trend of long-term, adverse impacts to meadow habitat in the Sierra Nevada region.

Riparian Communities

Riparian areas in the Sierra Nevada region have been directly affected with loss of habitat or have had their function impaired by various past and present human activities, including road construction, logging, grazing, development, and land drainage. Riparian areas are among the most ecologically productive and diverse terrestrial environments by virtue of their extensive land-water ecotone, the diversity of physical environments resulting from moisture gradients, and a mosaic of habitats created by dynamic river changes. Foothill areas below 3,300 feet appear to have experienced the greatest loss of riparian vegetation of any area in the region.

Proposed and approved projects inside Yosemite National Park and the El Portal Administrative Site that would adversely impact riparian vegetation include the Yosemite View Parcel Land Exchange and, potentially, the Mariposa Grove/South Entrance Site Planning and Hodgdon Meadow Water and Wastewater Treatment Improvement projects (NPS). These projects would contribute additional adverse impacts to riparian areas over the short term, but long-term impacts could occur with permanent loss of habitat if site design could not avoid the riparian areas. Designation of the Merced and Tuolumne Rivers as Wild and Scenic Rivers (including their headwaters), and development of Wild and Scenic River management plans would help guide management directions and levels of allowable impacts to these corridors in the future. Other projects, including erosion mitigation at many of the park’s campgrounds as well as ecological restoration of the Eagle Creek/Merced River confluence in Yosemite Valley, would improve the condition of currently impacted riparian areas.

Under the No Action Alternative, the piecemeal approach to restoration of riparian habitat in Yosemite Valley, El Portal, and Wawona would continue. Implementation of Wild and Scenic River management plans and river protection zoning and overlays would provide overall management direction for the river corridors. Implementation of management plans for adjacent wilderness areas managed by the USFS would also likely benefit riparian vegetation through a more comprehensive and unified approach. Therefore, Alternative 1, in conjunction with other plans and projects within riparian zones in and outside the park, would have negligible impacts to riparian zones in the Sierra Nevada region.

The overall cumulative impact to vegetation within the Sierra Nevada region as a result of foreseeable regional projects in conjunction with Alternative 1 of the Final Yosemite Valley Plan/SEIS would be adverse to upland plant communities, California black oak plant communities, and meadow plant communities. There would be negligible impacts to riparian plant communities.

This analysis describes impacts to wildlife in terms of habitat changes such as habitat loss or gain, degradation or enhancement, fragmentation or connectivity, level of human disturbance, and potential for increased or decreased conditioning of wildlife. The Vegetation section provided detail 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 National Park Service 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 Vol. Ia, Chapter 3, Affected Environment, Wildlife; table 3-6 illustrates the connections between vegetation types and wildlife habitats. Special-status wildlife species are discussed in a separate section of this chapter.

Short-term impacts would occur to wildlife during construction or implementation of actions described in this section. Based on the mitigation measures 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 HABITATS

The No Action Alternative would have a minor, beneficial effect on wildlife habitat in the areas that have been abandoned since the 1997 floods. The abandoned Upper and Lower River Campgrounds and the area of the abandoned Yosemite Lodge units are receiving greater wildlife use as they recover, compared to when they were active campgrounds and lodging facilities. Wildlife use can be expected to increase as these areas continue to recover. The benefit of this action is limited, however, given the high level of human activity that would still occur directly adjacent to these abandoned areas, especially the continued use of three multi-unit lodges that are in the floodplain. In addition, this alternative would result in the continued degradation and fragmentation of habitats in the east Valley through continued or increased human use.

The locations with potential for continued adverse impacts are described below.

Upland Habitats

Upland habitats are the most abundant type in Yosemite Valley, but current development and human activities have caused localized degradation of their value to wildlife. Such adverse effects that would continue under Alternative 1 include:

• The Curry Village tent cabins would continue to affect the quality of the ponderosa pine, mixed hardwood conifer, and riparian habitats they occupy. Forest understory would continue to be almost completely absent, affecting wildlife species that depend on that forest layer. The area would continue to be a source of human food for wildlife, resulting in alteration of wildlife behavior and threats to human safety. Hazard tree mitigation would continue to reduce the formation of snag habitat.

• Human use would continue to affect the mixed hardwood-conifer habitat at the Church Bowl Picnic Area by keeping understory vegetation from growing due to trampling. Food would continue to be available to wildlife, affecting their behavior.

• Fill material at Upper and Lower River Campgrounds would continue to support unnatural upland habitat and contribute to fragmentation of highly valued resource habitat types. Without this fill, the area would return to high-value types such as meadow, wetland, and riparian.

• Current levels of development inhibit the use of fire to manage vegetation, aid the spread of annosus disease, and are a factor in the spread of conifers into highly valued resource habitat types. Such factors alter the abundance and diversity of wildlife species dependent on highly valued resource habitats.

• Heavy vehicle traffic on existing roads would continue to fragment habitats. Wildlife using habitats in areas along the road would continue to be affected by traffic noise, lights, and moving vehicles. Traffic would continue to exacerbate the fragmentation effect of the road on habitats and wildlife movements, especially for small terrestrial organisms.

California Black Oak Woodland Habitat

California black oak woodland habitat has been severely affected by past and current human development and activities, causing fragmentation and reduction in this highly valued resource habitat type. Many wildlife species depend on black oaks for food and shelter. Under Alternative 1, the following adverse effects on black oak woodland habitat would continue:

• Upper and Lower River Campground, North Pines Campground, Backpackers and Group Campgrounds, and part of Lower Pines would continue to occupy areas that were partially black oak habitat.

• Factors resulting from current levels of development, such as altered hydrology from roads and structures, human trampling, landscape irrigation, and inadequate use of fire would continue to reduce black oak habitats, and affect their availability to wildlife.

• California black oak habitat, a highly valued resource type, would continue to be displaced by The Ahwahnee tennis courts, the former bank building, and the former gas station, locally affecting wildlife dependent on this habitat. However, these areas represent a relatively small portion of California black oak habitat in the Valley.

• The Ahwahnee Row houses would continue to displace natural habitat on the meadow/forest edge. Interface between meadow and forest habitats would continue to be affected. Intrusion of domestic pets and non-native plants into the meadow would continue to degrade habitat.

Riparian and Meadow Habitats

Riparian and meadow habitats have been the types most severely affected by past and present development and human activities, which has in turn adversely affected the numerous wildlife species that depend on these habitats. Current situations that would continue to adversely affect meadow and riparian habitats include:

• The Camp 6 area would continue to be used as parking and occupy upland and high-value potential riparian and wet meadow habitats, thus adversely affecting the species and abundance of wildlife in the area. This development would continue to interrupt the continuity of wet meadow habitat through the Valley. Radiating impacts from visitor use would continue to affect adjacent riparian and meadow habitats through human presence and trampling. Human/wildlife conflicts would continue to result from the availability of human food left in cars, trash cans, and litter. Dust raised by traffic on this unpaved parking area would continue to have an adverse effect on local wildlife through persistent dust on vegetation.

• Even though the orchards would not be actively maintained, they would continue to be the source of severe human/wildlife conflicts for many years. Bears would continue to be attracted to apples, causing extensive damage to vehicles parked in the orchard and threatening human safety. Deer attracted into the orchard also could injure people.

• The Yellow Pine Campground would continue to occupy and alter riparian and pine habitats. Existing riparian and wetland habitats would continue to be affected by radiating visitor use from the campground. Removal of hazard trees would affect the number of snags available to wildlife. Control and alteration of debris flow from Sentinel Creek to protect the campground would continue to affect habitat dynamics. The campground would continue to be a potential location for conditioning of wildlife to human food sources.

• Insufficient use of fire, because of its danger to existing development, would continue, leading to further conifer invasion of meadow habitats and reducing the availability of this important habitat to wildlife.

• Fill material, infrastructure, and buildings would continue to occupy areas that were naturally complex riparian habitat at Yosemite Lodge. Human trampling would continue to affect remaining riparian habitats in the area of Yosemite Lodge.

• Riparian and riverine habitats would continue to be degraded by the North and Lower Pines campsites adjacent to the Merced River, due to radiating impacts from associated human use, such as trampling of vegetation and disturbance of animals. Hazard tree mitigation in these areas would continue to limit the establishment of large, woody debris in rivers that provides substrate, nutrients, and cover for aquatic organisms. Management to protect campgrounds from river erosion may continue the use of bank stabilization techniques that would displace riparian habitats and restrict the formation of new habitats by preventing natural changes in river course.

• The abandoned Upper and Lower River Campgrounds and North Pines, Lower Pines, Backpackers, and Group Campgrounds would continue to occupy what was historically a complex matrix of meadow, riparian, and forest habitats. This would continue to be a major fragmentation factor in the band of wet meadow habitats that runs through the Valley. Although these areas would have less impact than if their use as campgrounds were renewed (some natural vegetation would return), the remaining fill, pavement, buildings, and infrastructure would prevent the return to natural habitat for wildlife, affecting the natural abundance and diversity of animal species.

• Many Housekeeping units would continue to occupy valuable riparian habitat and restrict the formation of new habitats through changes in river course. Management of hazard trees would continue to limit the formation of snag habitat and woody debris in the river. Concentrated human use would continue to be an abundant source of unnatural food to wildlife, leading to alteration in wildlife behavior and human/wildlife conflicts. Disturbance of wildlife in the camp and adjacent habitats would remain high.

• The rubble pile in Yosemite Creek would continue to alter stream dynamics, and thus the dynamics of natural habitat change downstream. Such disruption would continue to affect the abundance and diversity of wildlife found in these habitats.

• The obstruction of Bridalveil Creek by Southside Drive would continue to affect stream dynamics, and thus the diversity and succession of wildlife habitats in that area. Formation of valuable wetland and riparian areas would continue to be impeded.

• Roads would continue to obstruct natural water flows across Stoneman, Ahwahnee, Sentinel, Cook’s, and El Capitan Meadows, affecting the composition of wildlife habitat in these areas. The roads are also a likely barrier to the movements of some small animals that are reluctant to cross such an open area, resulting in habitat fragmentation. The existing roads lead to human intrusion into meadows, resulting in destruction of habitat and disturbance of animals. Roads can also be a source of pollution that affects aquatic species in adjacent meadows through degradation of water quality.

• Bridges would continue to affect stream dynamics and associated aquatic and riparian habitats. Deposition and scouring rates would continue to be altered, affecting streamside succession of wildlife habitats. These effects extend over long reaches of the river, both upstream and downstream of bridges.

• Riparian and pine habitats would continue to be affected at the Swinging Bridge Picnic Area. Heavy pedestrian traffic would keep nearly all understory vegetation from growing, and severe local disturbance of wildlife would continue. The area would continue to be a frequent source of human food to wildlife, through direct feeding, debris, and trash overflow.

OUT-OF-VALLEY HABITATS

No actions would be taken in out-of-Valley areas under this alternative. Wildlife habitats and populations would not be affected in these areas.

CONCLUSION

Habitat fragmentation would continue to have an adverse impact on wildlife and their habitat in the east Valley, with large areas of high-value habitat occupied by campgrounds, lodging units, and parking lots. This fragmentation of riparian, wetland, and meadow habitats has decreased the diversity and abundance of wildlife species in the Valley by affecting wildlife movements and the amount of contiguous habitat available to them. The effect of this fragmentation on wildlife is likely exacerbated by disturbance caused by large numbers of people in the park, their unrestrained access to sensitive habitats, and the high density of existing development. Developed areas that would be unused but not restored (i.e., Upper and Lower River Campgrounds and Yosemite Lodge cabin area) would provide better habitat than when they were used. Roads through sensitive environments would continue to adversely affect habitat quality and wildlife movements. Bridges would continue to adversely affect riparian and aquatic habitats by affecting river flow. Conditioning of wildlife to human food would continue at a high level in tent cabin areas, orchards, and picnic areas. Habitats in the west Valley and in out-of-Valley areas would remain relatively intact and unfragmented, except by existing roads and picnic areas. Overall, the impact of continued existing effects would be long term and adverse.

CUMULATIVE IMPACTS

In Yosemite’s 100-year history as a national park, incremental development has occurred to accommodate visitors, and park visitation has swelled; both have affected wildlife through degradation of habitat and direct disturbance. Habitat that has been altered or removed by development will not support a natural abundance and diversity of wildlife species because conditions for food, shelter, and reproduction are changed. Such impact extends beyond physical boundaries, because some animals are less likely to use habitats near heavily used areas such as roads, trails, campgrounds, and lodging areas. Within the park such degradation and disturbance are greatest in Yosemite Valley, with meadows bisected by roads, campgrounds and roads built up to river edges, large areas of habitat displaced by development, trails and roads running through and over riparian habitats, and nearly 2 million people visiting the Valley each year.

Outside of Yosemite Valley, impacts to park wildlife and their habitats tend to be smaller and more dispersed. Heavily traveled roads run through forest habitats, and small developments such as campgrounds, entrance stations, gas stations, and housing areas affect small areas of habitat. Larger concentrations of habitat degradation and disturbance occur at Wawona and Tuolumne Meadows, where concession operations, campgrounds, housing, and, in the case of Wawona, extensive private inholdings exist. Some areas of the park near its western boundary were logged around 1900. The construction of O’Shaughnessy Dam, which caused the inundation of Hetch Hetchy Valley and its extensive riparian, meadow, and wetland habitats, represents the greatest single change in wildlife habitat in Yosemite, both in area and magnitude.

Individually, the existing developments in Yosemite National Park have likely caused localized impacts to wildlife. These developments have affected abundance and diversity of species in those areas by changing the ability of habitats to provide necessary food, shelter, and reproduction sites. In total, these impacts have likely had an effect on parkwide wildlife populations, but because a majority of park habitats are relatively intact compared to those outside of the park, such an effect is thought to be minimal. The park has preserved some habitats, such as old growth forests, that are virtually nonexistent in the rest of the Sierra Nevada.

In addition, wider-scale, regional effects on wildlife and wildlife habitat outside the park have occurred across the Sierra Nevada as a whole. For example, a long history of logging, grazing, mining, and development outside the park has caused profound changes in habitat conditions and wildlife populations. A series of reservoirs on all major rivers have destroyed long stretches of riparian, meadow, and wetland habitats, affecting the full assemblage of species dependent upon these habitats.

Impacts to wildlife would also occur as a result of other present or reasonably foreseeable future projects (see Vol. II, Appendix H for a brief description of these projects). The effects of these projects would depend on several interacting factors, including the habitat type affected, extent of the area affected, quality of the habitat affected (e.g., level of existing disturbance), and distance of the area relative to the park and other similar habitats. Impacts on wildlife outside Yosemite National Park can magnify the adverse and beneficial effects of this alternative.

Many future or ongoing projects are limited in scope and would have minimal adverse effects on wildlife confined to specific development sites. Projects such as the Mariposa Creek Pedestrian/Bike Path (Mariposa Co.), Replacement/Rehabilitation of Yosemite Valley Sewer Line (NPS), El Portal Road Improvement Project (NPS), Yosemite Area Regional Transportation System (inter-agency), Mariposa Grove Roadway Improvement and Giant Sequoia Restoration (NPS), and O’Shaughnessy Compound Water System Improvements (City and Co. of San Francisco) would occur primarily in previously disturbed areas. Consequently, habitat loss would be minimal. Noise and human activity would likely disturb and possibly disperse wildlife in the site vicinity during the construction period (short term). However, long-term adverse impacts to area wildlife from such projects would be negligible due to current levels of disturbance or human activity at these sites and the localized nature of the effects.

Development projects such as the Rio Mesa Area Plan (Madera Co.); Highway 41 Extension (Madera Co.); University of California, Merced Campus (Merced Co.); and the City of Merced General Plan would occur some distance from the park, but are expected to adversely affect substantial areas of wildlife habitat over the long term. Effects include short-term habitat degradation due to noise and human activity during construction, as well as long-term habitat loss. Habitats affected would generally be dissimilar to those in the park (e.g., grasslands, agricultural lands), with different species likely affected. Consequently, interactive effects of these projects relative to park wildlife species would be negligible.

More substantial adverse impacts to wildlife are expected from other projects (such as the Yosemite View Parcel Land Exchange [NPS], Yosemite Motels Expansion, El Portal [Mariposa Co.], Hazel Green Ranch [Mariposa Co.], and El Portal Road Improvement Project, Segments A, B, and C) because these projects would affect important habitats within and in proximity to the park. Projects such as the Yosemite View Parcel Land Exchange (NPS) would result in long-term loss of important riparian habitat along the Merced River. Food, shelter, and reproductive sites necessary for riparian species would be lost by these actions. Chaparral habitat would be permanently lost near the park boundary due to the Yosemite Motels Expansion, El Portal (Mariposa Co.). Human activity associated with this facility would likely affect adjacent habitats and their use by less-tolerant species. The El Portal Road Improvement Project (Segments A, B, and C) has adversely affected some riparian habitats along the Merced River. The Hazel Green Ranch project, on the park’s boundary, could affect forest and meadow habitats.

Some future projects would have beneficial effects on wildlife habitat and populations. For example, the Merced River at Eagle Creek Ecological Restoration Project (Yosemite Valley) would restore and protect an area of highly valued riparian habitat in the Valley. Although the affected area is small, it would add to the extent and contiguity of this habitat for wildlife. The rehabilitation of Tamarack, Yosemite Creek, and Hodgdon Meadow Campgrounds and Bridalveil Horse Camp would help alleviate resource impacts associated with campground activities that are adversely affecting the quality of adjacent wildlife habitat. Sensitive habitats would be protected and restored, thus improving forage, cover, and reproductive sites for wildlife over the long term. Water quality in nearby streams would be enhanced through implementation of erosion and drainage control measures at the campgrounds, benefiting aquatic habitats and associated species.

In addition, several ongoing or future planning projects would potentially benefit wildlife over time, including the Fire Management Plan Update (NPS), Sierra Nevada Framework for Conservation and Collaboration (USFS), and Merced Wild and Scenic River Comprehensive Management Plan (NPS), Tuolumne Meadows Development Concept Plan (NPS), and Tuolumne Wild and Scenic River Comprehensive Management Plan (NPS). The Fire Management Plan Update (NPS) would result in a more ecosystem-based management of fire that would improve wildlife habitat by returning areas to a more natural and successional fire regime. Wildlife and their habitats would benefit parkwide over the long term through the creation of a more natural mosaic of vegetative successional stages, helping to restore natural abundance and diversity of wildlife species. Alternatives being considered in the Sierra Nevada Framework for Conservation and Collaboration planning initiative could lead to more ecosystem-based management of U. S. Forest Service lands surrounding the park. Actions under consideration include protection of wildlife and habitats over a wide area of the Sierra Nevada, including protection of critically impacted habitats. Implementation of these actions could reduce adverse impacts to park wildlife due to isolation as well as destruction of seasonally used habitats outside the park.

The Merced Wild and Scenic River Comprehensive Management Plan and Tuolumne Wild and Scenic River Comprehensive Management Plan would help identify critical wildlife and habitat resources associated with these rivers, and develop templates that would guide development and restoration such that important wildlife resources are protected and enhanced.

Clearly, the planning efforts described above have the potential to result in substantial beneficial impacts to wildlife over large areas. However, the magnitude of this effect would depend upon the alternative selected for each plan, and the level and timing of implementation of actions included in the selected alternative. These factors are unknown at this time.

When impacts of all present and reasonably foreseeable projects described above are considered in combination with Alternative 1, beneficial cumulative effects on wildlife would result over the long term. This conclusion is based primarily upon a conservative estimate of the effect that implementation of ongoing planning efforts that have goals and objectives for improved ecosystem management throughout the Sierra Nevada (e.g., Sierra Nevada Framework for Conservation and Collaboration) would have. Should substantial or full implementation of the actions included in these plans occur over time, however, long-term cumulative impacts on wildlife may, on balance, be beneficial to a greater degree. Long-term cumulative impacts on wildlife could continue to be adverse if implementation of these plans occurs sporadically or over a long time period.

Adverse cumulative impacts, including those under Alternative 1, would generally have local effects. Continued loss and fragmentation of habitats, especially riparian, meadow, and wetland, would continue to affect wildlife in the east Valley. The level of human disturbance in this area has likely affected use of intact habitats that remain. These effects have likely affected the local diversity and abundance of wildlife, especially when considered in combination with present and foreseeable projects near the park (e.g., Yosemite View Parcel Land Exchange and Yosemite Motels Expansion, El Portal). These projects and current effects in the park, however, would not have an appreciable effect on regional wildlife populations. Overall, cumulative impact would, therefore, be minor and beneficial, primarily from implementation of plans inside and outside the park that would affect wide areas of wildlife habitat.

| Table of Contents | Environmental Consequences | Alternative 1 | Alternative 2 |
| Part 1 | Part 2 | Part 3 | Part 4 |

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