AgdaPkt 2016-04-25 Closed and Joint SA PFA

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7.B. - Page 3 Aside from normal tidal action in Redwood Creek, over time the water surface elevation during an extreme storm or tidal event could exceed the top of the creek side wall with anticipated sea level rise. Stillwater is defined as the flood level not including the effects of waves or tsunamis, but including storm surge and astronomical tide. Today the 100- year Stillwater elevation is 9.7 ft. and still below the proposed creek side wall elevation. Relatedly, the daily mean higher high water (MHHW) level reaches an elevation of 7.4 ft., and assuming a sea level rise of 4.6 ft. by the year 2100 the MHHW would be 12.0 ft. and would overtop the creek side wall. Such a rise in sea level would impact other areas adjacent to Redwood Creek outside of the project area, which could be inundated by flooding. In the occurrence of this height of sea level rise, other measures would be needed to be implemented. While the project would not affect the height of sea level rise, over time there would be an increase in flooding potential due to the vicinity to Redwood Creek. As such, the height of the creek side wall may require retrofitting if future sea level rise in Redwood Creek results in frequent flooding of the path. If the IS/MND is adopted and the Undercrossing Project is approved, staff will move forward to complete the design and permitting necessary to advertise the project for construction bids. Design drawings for the Undercrossing Project are 95% complete. Permits are required from Caltrans, the U.S. Army Corps of Engineers, Regional Water Quality Control Board, and the California Department of Fish and Wildlife, and applications have been submitted to each entity. Additionally, PG&E and AT&T utilities must be relocated before the Undercrossing Project can proceed. Utility relocation can begin as early as summer, 2016, and is anticipated to take between six months and one year. The construction contract could be awarded thereafter in 2017, opening to the public by early 2018. ALTERNATIVES 1. Do not adopt the IS/MND and/or MMRP, and direct staff to provide additional CEQA analysis. 2. Do not approve the project design. FISCAL IMPACT Total construction cost is estimated to be up to $3,000,000, including utility relocation and permitting costs. $2,234,405.42 is available as of February 29, 2016 from developer contributions to project accounts for the Blomquist Bridge Element, which includes the Undercrossing Project. $500,000.00 will be available under a grant from the San Mateo County Transportation Authority (TA), awarded by their Board on March 3, 2016. Staff will soon begin the process of entering into a funding agreement between the City and the TA. When awarding the construction contract for the project, staff will request that the City Council authorize remaining funding to come from the Gas Tax Construction Fund and Traffic Mitigation Fees Fund as needed.