75B - PH ADOPT RESO FOR PR NO 15-6827

Home Browse Search

NT MENTS INITIAL STUDY/MITIGATED NEGATIVE DECLARATION FAIRVIEW BPIOGE REVLACEM REST TO STREET BEET) PROJECT L S A MAY 2020 (9Tx STREET To ANTx STREET) L, OLEGT SANTA ANAL CALIFOPHIA 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 the top of the 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 OH WM to the top of the 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. The proposed Project involves replacing the existing Fairview Street bridge with a wider roadway bridge. As shown on Figure 4, eight existing pier walls within the riverbanks (totaling approximately 0.09 ac) would be replaced with four new pier walls (totaling approximately 0.05 ac) within delineated USACE/RWQCB and CDFW nonwetland 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 United States would occur under the proposed Project. Specifically, there would be a net decrease of 0.0175 ac of permanent fill within delineated Waters of the United States, and a net decrease of 0.04 ac of permanent fill within delineated CDFW aquatic resources. As shown on Figure 4, a potential temporary bike detour route would be constructed within the Santa Ana River channel. This potential detour route would be constructed and deconstructed during dry -season work within the channel. The detour route would have a dirt base with an asphalt surface, and would be entirely removed following construction of the proposed Project. Impacts associated with the potential bike detour route shown on Figure 4 would amount to 0.11 ac of temporary fill within delineated Waters of the United States and 0.13 ac of temporary fill within delineated CDFW aquatic resources. In addition, temporary fills associated with dewatering activities and/or materials staging within the BSA will likely be required to complete the bridge removal and replacement. Such temporary fills would not permanently reduce channel capacity or result in the loss of aquatic resources. Indirect effects such as dust and construction -related runoff are also possible, but such impacts would be effectively avoided or minimized by implementing standard best management practices (BMPs) during construction. No compensatory mitigation is required because the proposed Project would not adversely impact any jurisdictional wetlands, riparian areas, or Waters of the United States. A net increase of channel capacity/Waters of the United States would occur with implementation of the proposed Project. Since work would be occurring within jurisdictional aquatic resources, resource agency permits (USACE Section 404 Nationwide Permit authorization, CDFW Section 1602 Streambed Alteration Agreement, and RWQCB Section 401 Water Quality Certification) will likely be required for the proposed Project. The purpose of these permits is to ensure that projects that impact jurisdictional areas do not impair water quality or habitat. The resource agency permits will include specific conditions to be implemented to avoid substantial impacts to water quality or habitat. Mitigation Measure 13I0-7 requires the submittal of permit applications and compliance with permit conditions In order to avoid impacts to aquatic resources within the Santa Ana River and adjacent habitat areas, standard BMPs are necessary to protect water quality and prevent the spread of invasive R:\WKE1702\ISMND\Fina1 ISMND\Fairview Street Bridge Final ISMND7c05rBBZ 9 3-25