3.6 Biological Resources
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3. Environmental Setting, Impacts, and Mitigation Measures 3.6 Biological Resources 3.6.1 Approach to Analysis This section describes the existing biological resources in and near WTTIP project sites and evaluates project-related impacts on those resources. Information used in the preparation of this section was obtained from the following resources: Reconnaissance-level surveys Records from the California Natural Diversity Database (CDFG, 2005) Biological literature of the region (EBMUD, 1994; CDFG, 2003; Hickman, 1993; Zeiner et al., 1990; Stebbins, 1985) Special-status species information from the U.S. Fish and Wildlife Service (USFWS, 2005a) Occurrence records on file at the University of California Berkeley Museum of Vertebrate Zoology (UCBMVZ, 2005) Vegetation and wildlife species occurrence information from EBMUD biologists (EBMUD, 2005; Skahill, 2005; Hartwell, 2005a, 2005b, 2005c; Lake, 2003; Loughman, 2002; Beeman, 2001; Swaim, 2000; Dunne, 1994) Vegetation types and wildlife habitats were characterized on the basis of both records and field observations. ESA conducted surveys of project sites on October 12, 13, and 20 and November 3 and 8, 2005 to gather information on plant communities, wildlife habitats, and habitat use on and surrounding each site. All areas evaluated at a project-level were inspected for biological and wetland resources during the field visits. A general tree assessment was completed to estimate the number of protected trees that would be affected in accordance with each city’s or county’s tree ordinance. 3.6.2 Setting Regional Setting The WTTIP project sites are located in the Oakland-Berkeley Hills and in the western Contra Costa County cities of Orinda, Moraga, Lafayette, and Walnut Creek in the San Francisco Bay Area. The Bay Area region supports a Mediterranean climate and a broad range of habitats, including mosaics of oak and mixed evergreen forests, native and non-native grasslands, chaparral, upland scrubs, marsh and wetland communities, and riparian scrubs and forests. The majority of proposed projects are located within areas of residential development. However, the Highland Reservoir and Pipelines and northern portion of the Moraga Road Pipeline alignment traverse the Lafayette Reservoir Recreation Area open space. The San Pablo Pipeline alignment is located in the San Pablo Recreation Area. In addition, the Fay Hill Reservoir is surrounded by a large expanse of undeveloped grassland. EBMUD WTTIP 3.6-1 ESA / 204369 Environmental Impact Report June 2006 3. Environmental Setting, Impacts, and Mitigation Measures San Pablo, Lafayette, Lauterwasser, and Las Trampas Creeks serve as the primary drainage system in the WTTIP project area.1 Lauterwasser Creek flows southwest into San Pablo Creek, which flows through the San Pablo Reservoir and on to San Pablo Bay. Lafayette Creek flows eastward to Las Trampas Creek. Las Trampas Creek joins with San Ramon Creek and becomes Walnut Creek, which flows north to Suisun Bay. Though these drainages are culverted at road and highway crossings and have underground reaches through developed urban areas, many portions of these drainages support native riparian and wetland vegetation and riffle structure within the streambed. WTTIP Project Sites Plant Communities and Associated Wildlife Habitats The WTTIP project area supports 13 plant communities consisting of riparian and upland woodlands, shrublands, grasslands, and developed areas. The plant communities and associated wildlife habitats present at each project site are listed in Table 3.6-1 and described below. Sensitive plant communities, defined as communities of high priority by the California Department of Fish and Game (CDFG), are indicated below and in Table 3.6-1. The plant community classification presented herein is based on field observations and the CDFG List of California Terrestrial Natural Communities Recognized by the California Natural Diversity Database (CDFG, 2003). Plant communities generally correlate with wildlife habitat types. Wildlife habitats were typically classified and evaluated using the CDFG’s A Guide to Wildlife Habitats of California (Mayer and Laudenslayer, 1988). Upland Woodlands Mixed Oak Woodland and Valley Oak–Coast Live Oak Woodland. Mixed oak woodland consists of a dense to sparse cover of multi-stemmed coast live oak (Quercus agrifolia) and valley oak (Quercus lobata) trees, with a partial understory of shrubs and grasses similar to the non-native grassland in upland areas. Occasionally, other native and non-native species may be found, such as black oak (Quercus kelloggii), blue gum eucalyptus (Euculyptus globulus), madrone (Arbutus menziesii), and California bay (Umbellularia californica). Valley oak and coast live oak can occur as the sole dominant species or may intermix to form a valley oak–coast live oak woodland community. The understory of both types of woodland can include poison- oak, coyote brush (Baccharis pilularis), as well as herbaceous species such as vetch (Vicia sp.) and mustards (Brassica spp.). Mixed oak woodland occurs at the Orinda WTP, Leland Isolation Pipeline and Bypass Valves (near Danville Pumping Plant), and Withers Pumping Plant sites, and along the proposed Orinda-Lafayette Aqueduct, Glen Pipeline, Highland Pipeline, Lafayette Reclaimed Water Pipeline, Moraga Road Pipeline, and Tice Pumping Plant and Pipeline alignments. Valley oak–coast live oak woodland occurs at the Happy Valley Pumping Plant and Highland Reservoir sites, and along the proposed Moraga Road Pipeline alignment. Valley oak– coast live oak woodland is a sensitive community, which is defined as a community of high priority by CDFG. 1 The project area consists of the WTTIP project sites and the surrounding habitat. EBMUD WTTIP 3.6-2 ESA / 204369 Environmental Impact Report June 2006 Biological Resources TABLE 3.6-1 PLANT COMMUNITIES AND WILDLIFE HABITATS WITHIN THE WTTIP PROJECT SITES Project Site Plant Communities and Wildlife Habitats Present Projects Analyzed at a Project Level Lafayette WTP Mixed Riparian Woodland Eucalyptus Woodland Coyote Brush Scrub Non-native Grassland Developed and Ornamental Landscaping Orinda WTP Mixed Riparian Woodland Mixed Oak Woodland Non-native Grassland Developed and Ornamental Landscaping Walnut Creek WTP Mixed Riparian Woodland Non-native Grassland Developed and Ornamental Landscaping Sobrante WTP Mixed Riparian Woodland Non-native Grassland Developed and Ornamental Landscaping Upper San Leandro WTP Developed and Ornamental Landscaping Orinda-Lafayette Aqueduct Mixed Riparian Woodland Mixed Oak Woodland Non-native Pine Woodland Coyote Brush Scrub Non-native Grassland Developed and Ornamental Landscaping Ardith Reservoir Non-native Pine Woodland Eucalyptus Woodland Developed and Ornamental Landscaping Donald Pumping Plant Eucalyptus Woodland Developed and Ornamental Landscaping Fay Hill Pumping Plant and Pipeline Improvements Non-native Pine Woodland (pipeline only) Developed and Ornamental Landscaping Fay Hill Reservoir Non-native Pine Woodland Non-native Grassland Glen Pipeline Improvements Mixed Riparian Woodland Mixed Oak Woodland Developed and Ornamental Landscaping Happy Valley Pumping Plant and Pipeline Mixed Riparian Woodland *Valley Oak–Coast Live Oak Woodland (pumping plant only) Non-native Annual Grassland Developed and Ornamental Landscaping (pipeline only) Highland Reservoir and Pipelines Mixed Riparian Woodland (pipeline only) Mixed Oak Woodland (pipelines, access roads only) *Valley Oak–Coast Live Oak Woodland (reservoir only) Non-native Pine Woodland (pipelines, access roads only) Coyote Brush Scrub Non-native Annual Grassland *Mixed Perennial Grassland *Cattail Wetland (pipeline only) EBMUD WTTIP 3.6-3 ESA / 204369 Environmental Impact Report June 2006 3. Environmental Setting, Impacts, and Mitigation Measures TABLE 3.6-1 (Continued) PLANT COMMUNITIES AND WILDLIFE HABITATS WITHIN THE WTTIP PROJECT SITES Project Site Plant Communities and Wildlife Habitats Present Projects Analyzed at a Project Level Lafayette Reclaimed Water Pipeline Mixed Riparian Woodland Mixed Oak Woodland Non-native Pine Woodland Coyote Brush Scrub Non-native Annual Grassland *Mixed Perennial Grassland Leland Isolation Pipeline and Bypass Valves Developed and Ornamental Landscaping Mixed Oak Woodland (near Danville Pumping Plant) Non-native Grassland (near Danville Pumping Plant) Moraga Reservoir Developed and Ornamental Landscaping Moraga Road Pipeline Mixed Riparian Woodland *Arroyo Willow Riparian Woodland Mixed Oak Woodland *Valley Oak–Coast Live Oak Woodland Non-native Pine Woodland Coyote Brush Scrub Non-native Grassland *Creeping Ryegrass Grassland *Mixed Perennial Grassland *Cattail Wetland Orchard Developed and Ornamental Landscaping Sunnyside Pumping Plant Non-native Grassland Non-native Pine Woodland Developed and Ornamental Landscaping Tice Pumping Plant and Pipeline Mixed Riparian Woodland (pipeline only) Mixed Oak Woodland Non-native Grassland Developed and Ornamental Landscaping Withers Pumping Plant Mixed Oak Woodland Non-native Pine Woodland Non-native Grassland Developed and Ornamental Landscaping NOTE: An asterisk (*) indicates a sensitive community, which is defined by the CDFG as a high priority community. SOURCE: ESA Oak woodland provides food and shelter for a variety of bird species, including insect eaters such as chestnut-backed chickadee (Poecile rufescens), white-breasted nuthatch (Sitta carolinensis), and warbling vireo (Vireo gilvus). Other species attracted to this habitat include song sparrow (Melospiza