Appendix A Natural Environment Study (Minimal Impacts)

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Natural Environment Study (Minimal Impacts) County habitats and other land cover types. Vegetation communities and land cover types within the BSA were assessed in the field, and a 1 "=100' scale aerial photograph was used to provide locational references. 2.2.3.2. JURISDICTIONAL DELINEATION Areas of potential jurisdiction were evaluated according to the most current USACE and CDFW regulatory criteria and guidance for the region (USACE 2008a, 2008b, 1992, 1991; Supreme Court of the United States 2006; RWQCB 2004). The boundaries of the potential jurisdictional areas within the BSA were observed in the field and mapped on an aerial photograph (1 " = 100' scale). Measurements of federal and State jurisdictional areas mapped during the course of the field investigation were determined by a combination of direct measurements taken in the field and measurements taken from the aerial photograph. Appendix D, Jurisdictional Delineation Report, provides further details regarding this survey effort. 2.2.3.3. DAYTIME BAT HABITAT SUITABILITY ASSESSMENT A daytime bat habitat suitability assessment was conducted to determine whether suitable bat roosting habitat is present in the Fairview Street bridge and immediate vicinity. A 300 ft buffer surrounding the bridge was included because of the potential for indirect impacts from Project -related lighting and/or noise. During the bat habitat assessment, the underside of the bridge structure was accessed on foot and examined to locate any potential bat roosting sites as well as evaluate the potential for bat foraging and roosting activity in the vicinity of the structure. Potential bat roosting sites were identified by examining the bridge for any structural features (e.g., crevices or recessed spaces) that may be suitable for use as day- or night -roosting habitat. Once identified, these areas were examined with a high- powered spotlight for the presence of bats or bat sign (e.g., guano, urine staining, or vocalizations) that would indicate current or past use of that feature by roosting bats. Because the presence of adjacent foraging habitat increases the desirability of a structure as a potential roost site, potential foraging habitat was also assessed within and immediately adjacent to the structures on the basis of vegetation composition, presence of water, connectivity to other areas providing suitable foraging or roosting habitat, and accessibility. 2.2.3.4. NIGHTTIME BAT EMERGENCE SURVEY The presence or absence of bat maternity colonies could not be confirmed during the daytime bat habitat suitability assessment because the structures were examined outside the bat maternity season (April 1—August 31). Therefore, a nighttime ............................................................................................................................................... . Fairview Street Improvements from 9th Street to 16th Street and Bridge Replacement Project 13