Chapter IV: Affected Environment Introduction This chapter presents topics included in the analysis of the Merced Wild and Scenic River Revised Comprehensive Management Plan/Supplemental Environmental Impact Statement (Revised Merced River Plan/SEIS) and a rationale for their inclusion. These topics were selected based on federal law, regulations and executive orders, National Park Service management policies, and concerns expressed by the public, park staff, or other agencies during the public scoping period. This chapter also provides a discussion of topics that were dismissed from further analysis. Existing conditions are described based on the most recent analyses completed for each topic area. The affected environment described in this chapter covers the geographical area included with all of the alternatives, and also includes areas adjacent to the Merced River corridor. The potential impacts of each alternative within each topic area are presented in Chapter V, Environmental Consequences. Because this document is a supplemental environmental impact statement to the original Merced Wild and Scenic River Comprehensive Management Plan and Final Environmental Impact Statement (Merced River Plan/FEIS), impact topics discussed below have been updated to reflect current conditions, where appropriate. In addition, some of the impact topics related to biological resources, cultural resources, and recreation in the El Portal area were updated to accurately reflect additional research conducted to identify and locate the Outstandingly Remarkable Values associated with these resources in the El Portal Administrative Site. Impact Topics Considered in this Plan Natural Resources The federal and state Endangered Species Acts (and associated legislation), Clean Water Act, Clean Air Act, and NEPA require that the effects of any federal undertaking examine natural resources. In addition, the National Park Service management policies and natural resource management guidelines call for the consideration of natural resources in planning proposals. Significant natural resources (such as rare, threatened, and endangered species) exist within the park and the El Portal Administrative Site and could be affected by implementation of the alternatives. Originating in Yosemite National Park, the Merced River traverses a region of abundant natural resources. It is therefore necessary to characterize both these natural resources and the environmental consequences to these resources that could result from implementation of Revised Merced River Plan/SEIS alternatives. Analysis was performed for the following natural resource topics: Geology, Geohazards, and Soils Hydrology, Floodplains, and Water Quality Wetlands Vegetation Final Revised Merced River Plan/SEIS IV-1 Chapter IV: Affected Environment Wildlife Rare, Threatened, and Endangered Species Air Quality Noise Cultural Resources The National Historic Preservation Act, the Archeological Resources Protection Act, Native American Graves Protection and Repatriation Act, and NEPA require that the effects of any federal undertaking on cultural resources be examined. In addition, National Park Service management policies and cultural resource management guidelines call for the consideration of cultural resources in planning proposals. Many historic and archeological sites, museum collections, historic buildings and structures, cultural landscape resources, and traditional cultural properties exist within the park and the El Portal Administrative Site and could be affected by the alternatives. Analysis was performed for the following cultural resource topics: Archeological Resources Traditional Cultural Resources Historic Sites, Structures, and Landscapes Visitor Experience Stewardship of Yosemite National Park requires the consideration of two integrated purposes: (1) to preserve Yosemite’s unique natural and cultural resources and scenic beauty, and (2) to make these resources available to visitors for study, enjoyment, and recreation. Different options for implementing a user capacity program and river boundaries in El Portal considered in the Revised Merced River Plan/SEIS could affect patterns of visitor use and the type and quality of visitor experiences. Analysis was performed for the following visitor experience topics: Recreation Orientation and Interpretation Visitor Services Wilderness Experience Scenic Resources Social Resources Analysis of social resources examines the effects of visitation on the social environment within the park and in the surrounding region, and how visitors experience social resources within the park. Transportation is analyzed because elements of the user capacity program presented in the alternatives considered in this Revised Merced River Plan/SEIS could affect how visitors circulate within and/or access the park. The park’s scenic resources are a major component of the park visitor’s experience. Conserving the scenery is a crucial component to the National Park Service 1916 Organic Act and the park’s enabling legislation. NEPA requires that socioeconomic impacts IV-2 Final Revised Merced River Plan/SEIS Chapter IV: Affected Environment of the Revised Merced River Plan/SEIS be addressed. The Revised Merced River Plan/SEIS could affect socioeconomic activity within the park and in the surrounding gateway communities. Analysis was performed for the following social resource topics: Land Use Transportation Socioeconomics Park Operations and Facilities Impact Topics Dismissed from Further Analysis Environmental Justice Environmental justice analyses determine whether a proposed action would have “disproportionately high and adverse human health or environmental effects . on minority populations and low-income populations.” The National Park Service and other federal agencies have determined that a disproportionately high and adverse effect on minority and low-income populations means an adverse effect that: (1) is predominately borne by a minority population and/or a low-income population, or (2) will be suffered by the minority population and/or low-income population and is appreciably more severe or greater in magnitude than the adverse effect that will be suffered by the non- minority population and/or non-low-income population. Potential adverse effects identified in an environmental justice analysis include air, noise, and water pollution; soil contamination; destruction or diminution of aesthetic values; destruction or disruption of community cohesion and economic vitality; displacement of public and private facilities and services; increased traffic congestion; and exclusion or separation of minority or low-income populations from the broader community. Of particular concern is the effect on property acquisition and displacement of people. No aspect of any alternative in the Revised Merced River Plan/SEIS would result in disproportionately high and adverse human health or environmental effects on minority populations or low-income populations. Any restriction on travel, lodging accommodations, or access to any area of the park that might result from the Revised Merced River Plan/SEIS would be equally applied to all visitors, regardless of race or socioeconomic standing. In addition, it is expected that minority populations comprising a portion of Yosemite visitation come from areas outside the immediate Yosemite area, such as the Central Valley, San Francisco, and Los Angeles, and have a variety of other recreation options available to them besides Yosemite National Park. Although levels of park employee housing in various areas may be affected by decisions made under the Revised Merced River Plan/SEIS, employee housing decisions are not expected to result in destruction or disruption of community cohesion and economic vitality, displacement of public and private facilities and services, increased traffic congestion, and/or exclusion or separation of minority or low-income populations from the broader community. Final Revised Merced River Plan/SEIS IV-3 Chapter IV: Affected Environment Prime and Unique Agricultural Lands There are no known agricultural lands directly involved in this plan, and thus no further discussion of this topic is necessary. Also, this plan would not have any direct or indirect effects to downstream agricultural lands. Public Health and Safety Public health and safety is not presented as a separate topic in this plan because many impact topic sections (water quality, recreation, park operations, and others) evaluate park-related public health and safety issues. Museum Collection The Yosemite Museum collection is not presented as a separate topic. This Revised Merced River Plan/SEIS, as a programmatic document, does not specifically call for any data collection activities. Future projects undertaken in the river corridor could require data collection. Any effect from these projects on the Yosemite Museum collection would be addressed under future compliance documents. Regional Setting Yosemite National Park lies on the western slope of the Sierra Nevada, a massive mountain range dividing central and northern California from more arid lands to the east. Elevations in the park range from approximately 2,000 to 13,114 feet. The total area within the park’s authorized boundary is 761,266 acres. The El Portal Administrative Site is approximately 1,398 acres. U.S. Forest Service land surrounds the park and is divided into four national forests: Stanislaus, Toiyabe, Inyo, and Sierra. The park includes lands within Mariposa,