DR-4569-CA Final Public Notice

FINAL PUBLIC NOTICE: Redwood Shores Sea Level Rise Protection Advance Assistance San Mateo County, California | HMGP 4569-230-007
 

The U.S. Department of Homeland Security’s Federal Emergency Management Agency (FEMA) proposes to provide federal financial assistance under the Hazard Mitigation Grant Program to the City of Redwood City in San Mateo County, California, to provide key planning steps in preparation of raising or adding to an existing levee system on the Redwood Peninsula. The proposed action would mitigate impacts from flooding and future sea level rise by developing a preferred alternative that would protect Redwood Shores from extreme storms, a FEMA 100- year tide, and approximately six feet of future sea level rise. Pursuant to Executive Order 11988 (Floodplain Management) and Executive Order 11990 (Wetlands Management) and FEMA’s implementing regulations at Title 44 of the Code of Federal Regulations Part 9, FEMA hereby provides interested parties with a notice of its final decision and an explanation of the alternatives that were considered.

The purpose of the proposed action is to protect Redwood Shores from flooding and sea level rise. The proposed action would complete planning activities in preparation for raising or adding to an existing levee system on the Redwood Peninsula. The proposed action consists of data collection, public outreach, completion of a 60 percent design, construction cost estimates, and development of required environmental documentation. Data collection would include coastal hazards analysis, hydrologic and hydraulic studies, land survey and utility location, topographic surveys, soil sampling, geotechnical investigation, and site reconnaissance along two potential levee alignments. Levee Alignment 1 would involve construction of approximately 3,330 feet of new levee, starting at the Marine Parkway entrance to U.S. Highway 101 (Highway 101), following the alignment of the existing Bay Trail on the northwest side of the Belmont Slough, and ending at Port Royal Park. Levee Alignment 2 would involve construction of approximately 1,860 feet of new levee, starting at about the same point as Alignment 1, and ending at the point where Belmont Slough makes a curve close to Highway 101, west of the Belmont Sports Complex and Conference Center. Following data collection and analysis, the City of Redwood City would identify one of those Levee Alignments as the preferred alignment option and then conduct geotechnical borings along that alignment only. Borings would occur every 1,000 feet along the preferred alignment, for a total of five borings, but exact boring locations are unknown at this time.

The entire Redwood Shores peninsula is depicted on FEMA Flood Insurance Rate Map (FIRM) Numbers 06081C0169G, 06081C0167G, 06081C0186F, 06081C0188F, effective April 5, 2019. Much of the peninsula lies within Zone X, designated as an Area with Reduced Flood Risk due to a Levee, with some areas mapped as Special Flood Hazard Area (SFHA) Zone A (no available base flood elevation, 1% Annual Chance Flood Discharge contained in lagoon). Levee Alignment 1 and Levee Alignment 2 are both located in Zone AE, with a 10-foot base flood elevation, and Zone X, Area with 0.2% Annual Chance Flood Hazard, or the 500-year flood.

The U.S. Fish and Wildlife Service’s National Wetlands Inventory map shows numerous estuarine and marine and freshwater emergent wetlands within the project area, as well as several lake and pond habitats within the project vicinity.

A map of the project area and its location within the floodplain and wetlands is available for public inspection. Parties interested in receiving a copy of the map should contact the FEMA Region IX Environmental Officer using contact information provided in this notice.

As stated above, the City of Redwood City would consider two potential levee alignments and would select the preferred alignment after various data collection processes. Selection of the preferred alignment would take into account the practicality of each option, as well as the differences in potential impacts to floodplains and wetlands. Geotechnical borings would only be conducted at the preferred levee alignment. FEMA has determined that the proposed project is the only practicable alternative available; therefore, the proposed action must be located in the floodplain and within wetlands. The proposed action would have no significant adverse impact on the floodplain or on wetlands and would benefit the area by reducing the risk of flooding and flood damage. Therefore, measures to minimize impacts on the floodplain and on wetlands are not necessary. The City of Redwood City has declared that the proposed action conforms to local floodplain standards, and would be responsible for the management, construction, and maintenance of the proposed action.

Additional information about FEMA’s proposed action may be requested by writing the FEMA Region IX Environmental Officer at FEMA, 1111 Broadway, Suite 1200, Oakland, California 94607, or fema-rix-ehp-documents@fema.dhs.gov. All requests should be received no later than 15 days after publication of this notice. No action will be taken before this date.