ENVISION SAN JOSÉ 2040 GENERAL PLAN UPDATE BIOLOGICAL RESOURCES EXISTING CONDITIONS REPORT Prepared by H. T. HARVEY & ASSOCIATES Prepared for David J. Powers and Associates 1885 The Alameda, Suite 204 San José, California 95126 20 March 2009 Project No. 2942-01 983 University Avenue, Building D Los Gatos, CA 95032 Ph: 408.458.3200 F: 408.458.3210 EXECUTIVE SUMMARY The City of San José, located in the northern portion of Santa Clara County, California, initiated an update of the City’s General Plan with a horizon year of 2040 known as Envision San José 2040. This existing conditions report describes the physical and biological conditions currently present within the area encompassed by the City of San José’s Urban Growth Boundary (“Study Area”) and will inform the process of updating the General Plan. BACKGROUND RESEARCH This report was based on a review of the current General Plan, San José 2020 (City of San José 1994), the working draft Santa Clara Valley Habitat Conservation Plan/Natural Communities Conservation Plan (HCP/NCCP; ICF Jones & Stokes 2008) currently in development, and area- specific documents such as the North San José Development Policies Update Program Environmental Impact Report (EIR) (City of San José 2005); the Evergreen – East Hills Vision Strategy Project Draft EIR (City of San José 2006) and the Draft Supplemental EIR for Revision of the Evergreen Development Policy (City of San José 2008); the Coyote Valley Specific Plan Draft EIR and comments on that Draft EIR (City of San José 2007a and 2007b); the Final Program EIR for the Alviso Master Plan (City of San José 1998); the South Bay Salt Ponds Restoration Project’s biological resources existing conditions report (H. T. Harvey & Associates 2005) and EIR (EDAW et al. 2007); a variety of biological databases, such as the California Natural Diversity Database (CNDDB 2009); and biological resources reports previously prepared by H. T. Harvey & Associates and others for various sites in the City of San José and vicinity. PHYSICAL CONDITIONS The Study Area is defined by the San Francisco Bay to the north, the Diablo Range to the east, and the Santa Cruz Mountains to the west. The majority of the Study Area occurs on the Santa Clara Valley floor and is relatively level. Elevations range from one foot below sea level in the Alviso area to approximately 400 feet elevation at the margins of the valley, with the highest elevations in the Study Area just above 800 feet in the Silver Creek Hills at the northern end of Coyote Ridge to the southeast and in the Santa Teresa Hills to the south. The climate in San José is typical of a Mediterranean climate, with mild, cool, wet winters and warm, dry summers. The lowlands of the Santa Clara Valley typically average 16 inches of rain annually, while the Diablo Range to the east may experience up to 30 inches/year, and the Santa Cruz Mountains to the west receives as much as 50 inches/year (SCS 1968). The Santa Clara Valley includes more than 800 miles of creeks and rivers, including 14 major waterways, in five major watersheds. The Santa Clara Valley has three major interconnected groundwater basins that supply nearly half of the total water used. Soils immediately surrounding baylands areas in the northern portion of the Study Area near Alviso tend to be fine- textured, clayey soils. Those soils in the valley lowlands and farther inland are more alluvial, deep, level soils, ranging from poorly to excessively drained, medium to fine-textured soils. Higher-elevation substrates in the Study Area may be sedimentary, basic igneous, and sometimes serpentine rock, with clayey, loamy textured soils (SCS 1968). Serpentine soils, which form Envision San José 2040 General Plan Update i H. T. Harvey & Associates Biological Resources Existing Conditions Report 20 March 2009 from weathered ultramafic rocks, support a unique assemblage of endemic plant and animal species in California. EXISTING NATURAL COMMUNITIES AND HABITATS Natural communities, land uses, and biotic habitats in most of the Study Area were recently mapped for most of the Study Area for the working draft HCP/NCCP (ICF Jones & Stokes 2008). That mapping formed the basis of the natural community and habitat maps and descriptions developed for this report. However, in the northern portion of the Study Area near Alviso, which was not mapped by the working draft HCP/NCCP, we mapped natural communities and habitats based on aerial photographs, USGS topographic maps, National Wetland Inventory maps, soils maps, previous reports by H. T. Harvey & Associates and others, personal experience, and limited ground-truthing as necessary. We also made minor revisions to the maps in the working draft HCP/NCCP based on our experience or ground-truthing in certain areas. H. T. Harvey & Associates biologists, using this mapping, identified eight general natural communities/land uses within the City of San José Study Area: grasslands, chaparral & coastal scrub, oak woodland, riparian forest and scrub, wetland, aquatic/open water, agricultural, and developed. These eight natural communities/land uses were further refined into 28 more detailed plant associations/wildlife habitats, for which the dominant and characteristic plant and animal species were described. WILDLIFE MOVEMENT Wildlife movement within or in the vicinity of the Study Area takes many forms, and is different for the various suites of species associated with these lands. Wildlife corridors, while long recognized as important, have been a major topic in conservation ecology over the past few decades, partly in response to increasing urban development and continued isolation of native habitats and species. The general overview of wildlife movement in the Study Area in this document focuses on existing conditions relating to situations where future growth may either impede movements, or areas where movement can be enhanced through thoughtful planning and policies. Major streams and associated riparian habitat corridors flowing through the City support anadromous fish runs, and have been identified as important landscape linkages. The stream and riparian corridors are rich habitats for wildlife and are also important corridors of movement, especially in areas such as the Coyote Valley where these intact linear habitats can connect broader open space preserves. The Coyote Valley, as depicted in the habitat maps, is primarily an agricultural area, but it is positioned between large tracts of open land that lie to the east and west of the valley. Movement of mammals, amphibians, and reptiles across this valley was relatively unobstructed historically. This connectivity changed as the Santa Clara Valley developed, particularly when Monterey Highway was constructed, the Coyote Canal was built, agriculture became dominant, and the U.S. 101 Freeway was constructed, and wildlife movement across Coyote Valley is at Envision San José 2040 General Plan Update ii H. T. Harvey & Associates Biological Resources Existing Conditions Report 20 March 2009 least somewhat impeded. The De Anza College Wildlife Corridor Stewardship Team has been studying wildlife use of, and movement within, Coyote Valley and has documented the movement of mammals through culverts under U.S. 101 and in fields throughout much of the valley. Wildlife movement across Monterey Highway has been less well studied. The South Almaden Valley Urban Reserve area, which supports a combination of rural residential areas and agricultural fields, does not have major physical barriers to wildlife movement, but it is more developed overall, especially at its northern end. The south end of the Santa Teresa Hills is characterized by extensive private open space providing ready movement into protected areas of the Santa Cruz Mountains. The Almaden Valley and Santa Teresa Hills thus provide avenues for wildlife movement within and between sections of the Santa Cruz Mountains and its foothills. In the Alviso area, an important movement corridor has long been recognized infringing non- tidal salt marshes that connect a major population center for the endangered salt marsh harvest mouse in New Chicago Marsh with the marshes of Coyote Creek. Without that corridor, the population south of Coyote Creek would be effectively isolated from areas north of the creek. This corridor includes several small patches of muted tidal and diked salt marsh at the northern edge of the Study Area. REGULATORY SETTING The following regulations pertaining to biological resources may apply to projects that will take place within the Study Area: the Clean Water Act Section 404 and 401, Porter-Cologne Water Quality Control Act, Rivers and Harbors Act, Federal Endangered Species Act, California Endangered Species Act, Magnuson-Stevens Fishery Conservation and Management Act, Federal Migratory Bird Treaty Act, California Environmental Quality Act, California Fish and Game Code, Santa Clara Valley Water District regulations, City of San José tree ordinance, City of San José Riparian Corridor Policy, and the City of San José General Plan policies. SPECIAL-STATUS SPECIES To develop a list of special-status species and sensitive habitats of concern that may occur in the Study Area, H. T. Harvey & Associates biologist collected and reviewed, in addition to the previously described documents, Rarefind data (CNDDB 2009); California Wildlife Habitat Relationships information; the Santa Clara County Breeding Bird Atlas (Bousman 2007a); and miscellaneous information available through the United States Fish and Wildlife Service (USFWS) including a list of special-status species potentially occurring in Santa Clara County using their website (http://www.fws.gov/sacramento/es/spp_list.htm), the California Department of Fish and Game (CDFG), and technical publications and previous reports by H. T. Harvey & Associates and others. We also reviewed information regarding wildlife use of Coyote Valley provided by De Anza College’s Wildlife Corridor Stewardship Team. For plants, we also consulted all CNPS lists (http://cnps.web.aplus.net/cgi-bin/inv/inventory.cgi) and applicable records to determine the probability of occurrence for all special-status plant species within the Study Area.