AgdaPkt 2020-12-07 Amended Joint SA PFA

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S.A. - Page 27 of 29 (S) OneShoreline Building Solutions for a Changing Climate Exhibit A Bayfront Canal and Atherton Channel Flood Protection and Ecosystem Restoration Project Scope of Work The Project generally proposes the installation of two 540 -foot long, 8 -foot wide by 5 -foot tall, underground concrete box culverts below Marsh Road at the entrance of Bedwell Bayfront Park. The culverts are designed to divert stormwater runoff during high tide conditions from the Bayfront Canal into managed ponds, which are a component of the South Bay Salt Ponds Restoration Project (SBSPRP). The connection to the managed ponds essentially increases the capacity of the Bayfront Canal and Atherton Channel to convey stormwater runoff from the Collaborative's respective jurisdictions. This additional capacity helps mitigate the impacts of flooding of residences and businesses in the communities proximate to Bayfront Canal and Atherton Channel from storm events up to a 25 -year return interval. Construction The Project includes the installation of two 540 -foot long, 8 -foot wide by 5 -foot tall, underground concrete box culverts, a lateral weir diversion structure on the Bayfront Canal; trash rack and service grate; sump pump with a 4 -inch drain line to Flood Slough; access shafts to the box culverts; outlet structure with headwall and riprap drainage connection to the Pond S5 Forebay (Forebay); the recontouring and lowering of a berm adjacent to the Forebay; and excavation of the Forebay for increased pond capacity. The proposed facilities are shown in Attachment 1 to this Scope of Work. Operations and Maintenance Activities Operations and Maintenance includes all activities required to maintain a fully functioning stormwater diversion facility. This work includes, but is not limited to: - Regular inspection of the Project area and facilities (quarterly between May and September, monthly between October and April, and before/after each major rain event) ; - Removal of trash, debris, and sediment from the trash rack, containment bin, sump pump, and outfall structures, as well as addressing of any necessary vandalism and repairs; - Maintaining the condition of the Project's built facilities including the intake structure, access shafts, outfalls, and riprap; - Ensuring the proper operation of the Project's built facilities, including the weir, box culverts, culvert gates, trash rack, sump pumps and outfall; - Providing electrical service to the automatic trash rack and dewatering sump pump and ensuring their proper functioning. - Coordination with property owners regarding access and activities - With the Don Edwards San Francisco Bay National Wildlife Refuge (Refuge), share operation and maintenance responsibilities of the Refuge's water control structures that manage desired water surface elevations, flows, and water quality in Refuge lands receiving water from Project facilities. Mitigation Monitoring and Maintenance All required inspection, monitoring, maintenance, reporting, restoration and replacement required by the project environmental documents and regulatory permits. Work will include, but not be limited to: site inspections, ground-based photo -monitoring, annual reporting to regulatory agencies, maintenance and restoration of planting materials including the temporary irrigation system. ATTY/AGR.2020.270/FSLRRD, Atherton, Menlo Park and County (MEMORANDUM OF UNDERSTANDING) (Page 14 of 15)