Environmental Setting and Impacts
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CHAPTER IV Environmental Setting and Impacts This chapter describes the environmental setting and analyzes the potential impacts associated with the removal of Sunol and Niles Dams. As described in Chapter II, this chapter provides the detailed analysis of environmental issues. The environmental setting presents both regional context and site-specific details of the existing conditions to provide a basis for identifying potential impacts due to project implementation. This chapter also includes, for each environmental issue, a description of significance criteria used in analyzing potential impacts. Based on these criteria, impacts determined to be significant or potentially significant would require mitigation measures. The impact analysis indicates whether or not mitigation measures are available to reduce impacts to a less-than-significant level; the reader is referred to Chapter V for a detailed description of mitigation measures. In some cases where impacts are determined to be less than significant, the impact analysis recommends improvement measures that could reduce adverse effects or temporary disruption; however, these measures are not required under the California Environmental Quality Act (CEQA). A. Compatibility with Local Plans and Policies The City and County of San Francisco, as a chartered city and county, and the San Francisco Public Utilities Commission (SFPUC), as a public utility, receive intergovernmental immunity under California Government Code Sections 53090 et seq. Such immunity exempts the extraterritorial lands owned by the City and County of San Francisco, through the SFPUC, from the planning and building laws of any other city or county in which those lands are located. Thus, the zoning and building codes, general plans, specific plans, and other planning and building policies of Alameda County, or various regional plans, do not apply to this project. The SFPUC has authority over the management, use, and control of its extraterritorial lands under the San Francisco City Charter, Section 4.112 (San Francisco City Charter, 2004). San Francisco’s planning and building laws, to the extent that they apply to San Francisco’s extraterritorial lands, could be applicable to the proposed project, as long as they do not conflict with the SFPUC’s charter responsibilities. Similarly, the San Francisco General Plan (City of San Francisco, 1996) applies primarily to lands within the City and County of San Francisco, and there are no specific policies directed to areas outside of these boundaries, although general environmental resource policies in the San Francisco General Plan could be applicable to the project site. The San Francisco General Plan, which provides general policies and objectives to guide land use decisions, contains some policies that relate to physical environmental issues. The compatibility of the project with policies that do not relate to physical environmental issues will Case No. 2001.1149E IV.A-1 ESA / 201591 Sunol/Niles Dam Removal Project October 2005 Environmental Setting and Impacts Compatibility with Local Plans and Policies be considered by decision makers as part of their decision to approve or disapprove the proposed project; any potential conflicts identified as part of that process would not alter the physical environmental effects of the proposed project. The SFPUC seeks to manage its lands in a way that is consistent with San Francisco’s planning and building laws and works cooperatively with local jurisdictions to avoid conflicts with local planning and building laws. Nevertheless, the laws of other jurisdictions are nonbinding on the SFPUC’s management of its lands. The referenced excerpts from the general plans of Alameda County and various regional plans are presented in this report for informational purposes only. Setting Project Area The proposed project area lies along State Route 84 (SR 84) in Alameda County, east of Fremont, between the communities of Niles and Sunol (see Figures 1 and 2). SR 84 parallels Alameda Creek and intersects SR 238 to the west of the project area and Interstate 680 (I-680) to the east. Sunol and Niles Dams are located on Alameda Creek in the Alameda Creek watershed. The Alameda Creek watershed contributes to the SFPUC water supply. The dams were built as part of the SFPUC water supply system. Due to system upgrades, they no longer aid in the provision of water to downstream portions of the system. Niles Dam Niles Dam is located approximately two miles east of Niles District, a section of the city of Fremont. The Niles Dam project site is located at the eastern edge of Fremont and is surrounded by low-density development (City of Fremont, 2004). The Niles Dam site has three land use designations under the Fremont General Plan: Hill Face Open Space (Development Reserve Boundary), Hill Open Space (Development Reserve Boundary), and Hill Open Space (City of Fremont, 2004). The Niles Canyon Railroad (NCRR, right-of-way formerly owned by the Southern Pacific Railroad) runs along the south bank of Alameda Creek about 150 feet southeast of the dam. The right-of-way is owned by Alameda County (City of Fremont, 2001). The Union Pacific Railroad (UPRR, formerly owned by the Western Pacific Railroad) right-of-way runs adjacent to the south bank of Alameda Creek about 2,000 feet south of the dam. The northern bank of Alameda Creek rises steeply and has limited vegetation. Vargas Plateau Regional Park, which is designated as Parklands in the Fremont General Plan, lies just south of the site across the UPRR right-of-way. Sunol Dam Sunol Dam is located in unincorporated Alameda County adjacent to the community of Sunol along SR 84 east of Niles Dam. Its land use designation in the Alameda County East County Area Plan is Agriculture (Alameda County, 2002). The UPRR and the NCRR, which generally run parallel to Alameda Creek in Niles Canyon, lie about 100 and 300 feet to the north, respectively, Case No. 2001.1149E IV.A-2 ESA / 201591 Sunol/Niles Dam Removal Project October 2005 Environmental Setting and Impacts Compatibility with Local Plans and Policies on either side of SR 84. The northern bank of Alameda Creek adjacent to Sunol Dam is characterized by dense riparian vegetation. A commercial (garden) nursery occupies the low- lying, flat area along the north side of the dam and its upstream reservoir. According to the East County Area Plan (Alameda County, 2002), the primary land use designations in the vicinity of Sunol Dam are Agriculture, Water Management, and Resource Management. Plans and Policies The SFPUC is in the process of preparing a habitat conservation plan for the Alameda Creek watershed. Currently, there are no habitat conservation or natural community plans for the project area. Plans and policies adopted for the project area are summarized below and are presented for informational purposes only. Alameda County General Plan East County Area Plan The East County Area Plan (ECAP), one of the three area plans that make up the Alameda County General Plan, addresses unincorporated areas of Alameda County. The other two area plans are the Castro Valley Area Plan and the Eden Area Plan. The ECAP, adopted in May 1994 (last amended 2002), includes the cities of Dublin, Pleasanton, Livermore, and small portions of Hayward. The Alameda County General Plan also includes five countywide functional elements: the Regional Element, Housing Element, Energy Element, Natural Resources and Open Space Element, and the Safety and Noise Element. The Sunol Dam site is located in the unincorporated portion of Alameda County in the planning area addressed by the ECAP. General Open Space Policy 52: The County shall preserve open space areas for the protection of public health and safety, provision of recreational opportunities, production of natural resources (e.g., agriculture, windpower, and mineral extraction), protection of sensitive viewsheds, preservation of biological resources, and the physical separation between neighboring communities. Sensitive Viewsheds Policy 116: The alternation of natural topography, vegetation, and other characteristics by grading, excavating, filling or other development activity shall be minimized. To the extent feasible, access roads shall be consolidated and located where they are least visible from public view points. Policy 117: The County shall require that where grading is necessary, the offsite visibility of cut and fill slopes and drainage improvements is minimized. Graded slopes shall be designed to simulate natural contours and support vegetation to blend with surrounding undisturbed slopes. Policy 118: The County shall require that grading avoid areas containing large stands of mature, healthy vegetation, scenic natural formations, or natural watercourses. Case No. 2001.1149E IV.A-3 ESA / 201591 Sunol/Niles Dam Removal Project October 2005 Environmental Setting and Impacts Compatibility with Local Plans and Policies Policy 119: The County shall require that access roads be sited and designed to minimize grading. Biological Resources The goal of the ECAP as it pertains to biological resources is, “To preserve a variety of plant communities and wildlife habitat.” Objective 1. Tree Preservation Policy 110: Alameda County requires that developments are sited to avoid or, if avoidance is infeasible, to minimize disturbance of large stands of mature, healthy trees and individual trees of notable size and age. Where healthy trees are removed, the County requires a tree replacement program which includes a range of tree