Appendix A Natural Environment Study (Minimal Impacts)

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Natural Environment Study (Minimal Impacts) 4.1.1.1. SURVEY RESULTS The Santa Ana River within the BSA is an unvegetated, concrete -lined intermittent drainage feature. This channel conveys flows attributed to local urban runoff and seasonal storm water. The low -flow channel located within the center of the channel bed had standing water at the time of the field survey. The Santa Ana River has an OHWM determined to be 21 ft up from the channel bed. Downstream of the BSA, the channel has a direct nexus to the Pacific Ocean (a navigable water of the U.S.) and is tidally influenced at its mouth. However, the tidal influence does not extend to the BSA, and there are no waters subject to jurisdiction under Section 10 of the Rivers and Harbors Act. There are no wetlands or riparian areas present within the BSA. The total acreage of potential non -wetland USACE jurisdiction within the BSA is 4.18 ac. Because there is no current publicly issued guidance on determining RWQCB jurisdictional areas, jurisdiction was determined based on the federal definition of waters of the U.S. as recommended by the State Water Resources Control Board's Workplan: Filling the Gaps in Wetland Protection (2004). RWQCB jurisdiction is considered coincident with USACE jurisdiction (4.18 ac) for purposes of CWA Section 401 certification. Under California Fish and Game Code Section 1602, the CDFW takes jurisdiction over rivers, streams, and lakes. The State's jurisdiction generally includes the streambed/lakebed to top of bank and to the outer edge of associated riparian vegetation, where present. Within the BSA, California Fish and Game Code aquatic resources extend beyond the OHWM to the top of bank within the trapezoidal portions of the Santa Ana River. There is no associated riparian vegetation within the BSA. The total acreage of potential CDFW streambed jurisdiction within the BSA is 5.55 ac. 4.1.1.2. PROJECT IMPACTS The Project involves replacing the existing Fairview Street bridge with a wider roadway bridge. As shown on Figure 3, eight existing pier walls within the river banks (totaling approximately 0.09 ac) would be replaced with four new pier walls (totaling approximately 0.05 ac) within delineated USACE/RWQCB and CDFW non - wetland aquatic resources. The total proposed permanent fill is 0.05 ac for USACE/ RWQCB- and CDFW-delineated aquatic resources. Since the proposed support structures are smaller in area than the existing support structures, a net increase in channel capacity/waters of the U.S. would occur under the Project. Fairview Street Improvements from 9th Street to 16th Street and Bridge Replacement Project 33