Appendix A Natural Environment Study (Minimal Impacts)

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Natural Environment Study (Minimal Impacts) (refer to Appendix C, Representative Site Photos). These girders form cavities in the underside of the bridge deck that trap warm air and offer shelter from the wind. Cliff swallow (Petrochelidon pyrrhonota) mud nests were also present throughout the girders of the bridge at the time of the assessment. The swallow mud nests may also provide day -roosting habitat for bat species, including Yuma myotis and Mexican free -tailed bats, which have been documented day roosting in swallow mud nests and may use the mud nests observed on the bridge structure. Although the Santa Ana River is unvegetated and concrete lined in the vicinity of the Fairview Street bridge, water within the channel as well as ornamental vegetation associated with nearby residences provides foraging habitat for a variety of bat species, thereby increasing the likelihood that this structure is used for roosting. No bats were observed during the daytime habitat assessment or the nighttime emergence survey; however, some scattered guano was observed beneath the hinges, confirming the use of these crevices by individual bats. A concrete double -box culvert is situated within 300 ft of the Fairview Street bridge over the Santa Ana River. This culvert structure was not entered during the assessment because the entrances to each box were partially gated and because there were indications of human habitation, both of which presented potential safety considerations as well as reducing the likelihood that roosting bats were present. 4.1.6.2. PROJECT IMPACTS Since the existing Fairview Street bridge over the Santa Ana River will be demolished for the Project, potential direct and indirect impacts to roosting bats may occur. However, there is no evidence of maternity colonies roosting within the BSA. As long as the avoidance and minimization efforts discussed below are implemented, the Project is not expected to adversely impact protected bat species. The new Fairview Street bridge to be constructed under the Project may provide additional roosting habitat for protected bat species. 4.1.6.3. AVOIDANCE AND MINIMIZATION EFFORTS/COMPENSATORY MITIGATION The following measures will be implemented to minimize the potential for take of individual roosting bats and impacts to suitable day- and night -roosting bat habitat within the Fairview Street bridge over the Santa Ana River: ................................................................................................................................................ . Fairview Street Improvements from 9th Street to 16th Street and Bridge Replacement Project 43