4.4 BIOLOGICAL RESOURCES This section describes the existing biological resources within the region and evaluates the significance of the changes in biological resources that would result from development of the proposed RTP/SCS, and feasible mitigation measures to reduce these potential impacts. Sources utilized in this discussion include data provided by the US Fish and Wildlife Service (USFWS), the California Native Plant Society (CNPS), and the California Department of Fish and Wildlife (CDFW). 4.4.1 ENVIRONMENTAL SETTING San Joaquin County is located within the San Joaquin Valley between the Sierra Nevada mountain range in the east and the Sacramento River–San Joaquin River Delta in the west. The County has over 900,000 acres and 1,400 square miles. It is characterized by an extensive north-south trending valley floor through the central County with gentle foothills rising along the eastern County, the Delta in the northwest, and the beginning of the coastal foothills to the southwest. Sacramento County borders the County to the north, while Stanislaus County is located to the south. Contra Costa and Alameda Counties are located to the west, and Amador, Calaveras and Stanislaus counties border San Joaquin County on the east. The Mokelumne River to the north, the Calaveras River and Mormon Slough in the center, and the Stanislaus River along the County’s southern border, flow through the County, predominantly east to west. The San Joaquin River flows north into the Delta through the south-central portion of the County. Old River forms a portion of the County’s western boundary and defines the southern boundary of the Primary Zone of the Delta within the County. The Delta-Mendota Canal and the California Aqueduct trend northwest to southeast in the southwest portion of the County. Primary creeks in the County include Dry Creek to the north; Corral Hollow, Hospital Creek, and Lone Tree Creek in the southwest; Little Johns Creek, Duck Creek, and a second Lone Tree Creek in the southeast; Mosher Slough, Bear Creek and Paddy creeks in the northeast and Potter Creek in the mid-east portion of the County. The northwest portion of the County is covered by the extensive sloughs and rivers of the Delta. Approximately 43 percent of the Sacramento/San Joaquin Delta Primary Zone is located in San Joaquin County. San Joaquin County was formerly dominated by riparian woodland, oak savannah, wetlands, saltbush, and perennial grassland communities that harbored an abundance of endemic wildlife and plant species. The San Joaquin Valley is now a vast agricultural region with a marked reduction of native habitats and the associated populations of plants and wildlife. Urban and industrial development has also contributed Impact Sciences, Inc. 4.4-1 2014 San Joaquin COG RTP/SCS Draft EIR 1173.001 March 2014 4.4 Biological Resources to the major habitat losses, which have occurred since the boom in agricultural development in the late 1800s. Less than 4 percent of the original native habitat remains of that estimated in historic times. The majority of the County consists of a combination of agricultural and urban environments that have been drastically altered from their native state by human activities. Native terrestrial habitat types that still exist in the County include chaparral, grassland, oak woodland/savannah, and riparian woodland. Aquatic habitat types remaining in the County are represented by lakes, streams, rivers, and wetlands such as sloughs, marshes, and vernal pools and this aquatic environment supports a rich fishery. Climatic and physiographic differences distinguish the various terrestrial and aquatic communities. Unique biological resources are contained within each of these habitats. In addition to providing habitat for resident wildlife and plant species, this region also functions as an important dispersal corridor for wildlife and a vital link in the migratory pathway of the Pacific Flyway. Local Biological Features Geomorphic Provinces California’s geomorphic provinces are naturally defined geologic regions that display a distinct landscape or landform. Earth scientists recognize 11 provinces in California. Each region displays unique, defining features based on geology, faults, topographic relief, and climate. These geomorphic provinces are remarkably diverse. They provide spectacular vistas and unique opportunities to learn about earth’s geologic processes and history. San Joaquin County is located in the Great Valley geomorphic province of California. Great Valley The Great Valley is an alluvial plain about 50 miles wide and 400 miles long in the central part of California. Its northern part is the Sacramento Valley, drained by the Sacramento River and its southern part is the San Joaquin Valley drained by the San Joaquin River. The Great Valley is a trough in which sediments have been deposited almost continuously since the Jurassic period (about 160 million years ago). Great oil fields have been found in southernmost San Joaquin Valley and along anticlinal uplifts on its southwestern margin. In the Sacramento Valley, the Sutter Buttes, the remnants of an isolated Pliocene volcano, rise above the valley floor. Bioregions The County is located within the Bay Area/Delta bioregion and is surrounded by four different bioregions: Sacramento Valley to the north, Sierra to the east, San Joaquin Valley to the South, and the Central Coast to the southwest. A brief description of the Bay Area/Delta bioregion is discussed below. Impact Sciences, Inc. 4.4-2 2014 San Joaquin COG RTP/SCS Draft EIR 1173.001 March 2014 4.4 Biological Resources Bay Area Delta Bioregion The Bay Area/Delta Bioregion extends from the Pacific Ocean to the Sacramento Valley and San Joaquin Valley bioregions to the northeast and southeast, and a short stretch of the eastern boundary joins the Sierra Bioregion at Amador and Calaveras counties. The bioregion is bounded by the Klamath/North Coast on the north and the Central Coast Bioregion to the south. The Bay Area/Delta Bioregion is one of the most populous areas of the state, encompassing the San Francisco Bay Area and the Sacramento-San Joaquin River Delta. The water that flows through the Delta supplies two-thirds of California’s drinking water, irrigating farmland, and sustaining fish and wildlife and their habitat. The bioregion fans out from San Francisco Bay in a jagged semi-circle that takes in all or part of 12 counties: Alameda, Contra Costa, Marin, Napa, San Francisco, San Joaquin, San Mateo, Santa Clara, Solano, Sonoma, and parts of Sacramento, and Yolo. The habitats and vegetation of the Bay Area/Delta Bioregion are as varied as the geography. Terrestrial Biota and Habitats It is important to note that plant communities are not always clearly defined with strictly delineated boundaries. Plant communities are dependent on or affected by factors such as geographical location, soil types, precipitation rates, solar aspect, and orientation of slopes, elevations, microclimates, and successional considerations. Therefore, it is not uncommon to find a particular plant or grouping of plants growing outside an area that would be considered their customary habitats if some of the above factors are advantageous to that growth. The following brief descriptions were taken from the County’s 2009 General Plan Background Report and represent the distinct ecological communities in the regions. Urban/Developed Urban or developed land is comprised of areas of intensive use with much of the land covered by structures. Included in this category are cities, transportation, power and communications facilities, residences, mills, shopping centers, industrial and commercial complexes, and institutions that may, in some instances, be isolated from urban areas. Agricultural land, forest, wetland, or water areas on the fringe of urban or built-up areas are not included in this category except where they are surrounded and dominated by urban development. Agriculture Agricultural land may be defined broadly as land used primarily for production of food and fiber and includes crop fields, orchards, vineyards, and grazing lands. The number of building complexes is smaller and the density of the road and highway network is much lower in agricultural land than in Impact Sciences, Inc. 4.4-3 2014 San Joaquin COG RTP/SCS Draft EIR 1173.001 March 2014 4.4 Biological Resources urban or developed land. Lands producing economic commodities such as wild rice, cattails, or certain forest products commonly associated with wetlands are excluded from the agriculture category and carry a wetlands designation. Similarly, when wetlands are drained for agricultural purposes, then they are included in the agriculture category. Agricultural lands that are no longer in use and where wetland vegetation has reestablished are included in the wetlands category. Annual Grassland Annual grassland is one of the most common plant communities in San Joaquin County, particularly in the eastern and southwestern areas. As in other Central Valley counties, native grassland species have been largely replaced over time by non-native species, which are now dominant. This community occurs on ridges, hill slopes, and valley floors. Species composition varies but typically includes non-native grasses such as soft chess, red brome, ripgut brome, foxtail barley, wild oat, and annual fescues, intermixed with herbaceous species such as mustard, lupine, owl’s clover, poppy, and various species of filaree. Most annual grasslands in the County have been subjected to grazing or frequent human activities, such as maintenance measures along roadsides. The annual grassland vegetation in these areas is often dominated by introduced weedy and invasive species, such as yellow star thistle. Grasslands are important habitats because they support pollinating insects, amphibians, reptiles, and small birds and mammals that are prey for other wildlife, such as red-tailed hawks, northern harriers, American kestrels, burrowing owls, coyotes, and gray foxes. Grasslands near open water and woodland habitats are used by the greatest number of wildlife species because the woodlands provide additional places for resting, breeding, and escape.