DR-4569-CA Public Notice 003

FINAL PUBLIC NOTICE: Estudillo Canal and Neptune Drive Flood Protection Project, Alameda County, California | HMGP 4569-468-014R 

The U.S. Department of Homeland Security’s Federal Emergency Management Agency (FEMA) intends to provide federal financial assistance under the Hazard Mitigation Grant Program to the Alameda County Flood Control and Water Conservation District in Alameda County, California to modify the Estudillo Canal by making improvements to the tidegate, lowering a portion of the canal, and creating a berm and floodwall along Neptune Drive. The proposed action would mitigate impacts from flooding by increasing flow capacity and redirecting flow in the Estudillo Canal, thus increasing shoreline protection at Neptune Drive to prevent coastal flooding from entering the project area. 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 reduce flood hazards. The proposed action consists of improvements to the Estudillo Canal, including expanding the capacity of the existing tidegate to allow for greater discharge flows, lowering a section of the southern canal bank to allow for temporary water storage in existing holding basins (“retention ponds”), and salt marsh modifications. The proposed action also involves shoreline flood protection components along Neptune Drive, primarily the construction of a berm and floodwall.

The project area is in the 100-year floodplain as depicted on the FEMA Flood Insurance Rate Map (FIRM) Numbers 06001C0258H and 06001C0254H, both with an effective date of December 21, 2018. The FIRM shows that the Estudillo Canal project area, in Panel 06001C0258H, lies within Special Flood Hazard Area (SFHA) Zone AE, an area that has a 1-percent probability of flooding every year and where predicted base floodwater elevations (BFEs) are 10 feet. The Neptune Drive project area, in Panel 06001C0254H, is also in SFHA Zone AE with a 1-percent probability of flooding every year and a BFE of 10 feet.

The U.S. Fish and Wildlife Service National Wetlands Inventory map shows five wetlands within the project boundaries and adjacent areas. The Neptune Drive project area is directly adjacent to a 210.33-acre estuarine and marine wetland. The Estudillo Canal project area overlaps with the edge of 261,265.24 acres of estuarine and marine deep-water and 2.41 acres of estuarine and marine wetland and is adjacent to a 15.11-acre lake habitat. A map of the project area and its location within the floodplain 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.

Alternatives to the proposed action were considered, including lowering the elevation of the southern embankment of the canal by smaller, varying extents, as well as raising the grade of the site. These alternatives are not recommended, either because they would not provide large flood stage reductions north of the canal, or because they would require a large amount of soil and necessitate the replacement of an existing residence. FEMA has determined that the proposed project is the only practicable alternative available; therefore, the proposed action must be in the floodplain. The proposed action would have no significant adverse impact on the floodplain and would benefit the area by reducing the risk of flooding and flood damage. Therefore, measures to minimize impacts on the floodplain are not necessary. The Alameda County Flood Control and Water Conservation District 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.