DR-4558-CA Public Notice 005

INITIAL PUBLIC NOTICE: Kimball Dam Raise (Advance Assistance), Napa County, California | HMGP-4558-548-040

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 City of Calistoga in Napa County, California, to evaluate and design structural improvements for the Kimball Dam and spillway to mitigate flood risks by increasing the reliability of the dam and spillway. Pursuant to Executive Order 11988 (Floodplain 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 intent to carry out an action affecting a floodplain.

The purpose of the proposed action is to reduce flood hazards. The proposed action consists of 1) developing hydrologic and hydraulic studies; 2) conducting technical studies including topographic surveys and geotechnical exploratory borings; 3) preparation of a preliminary engineering report; 4) completion of a final design technical memorandum with 60 percent, 90 percent, and 100 percent design plans; 5) preparation of applicable permits; and 6) completing the California Environmental Quality Act documentation and supporting environmental studies needed to construct the project.

The proposed action would require 12 geotechnical exploratory borings, each 100 feet deep with a total disturbance of 25 square feet per boring. Six of the borings would occur on the upstream face of the dam, requiring in-water work. The remaining six borings would occur on the downstream side of the dam and would not require any in-water work.

The project area is in the 100-year floodplain as depicted on the FEMA Flood Insurance Rate Map (FIRM) Numbers 06055C0230E, effective date September 26, 2008. The FIRM shows that the project area lies primarily within Zone X, an area of minimal flood hazard. A portion of the project area, an existing access road and one of the proposed staging areas, is within Zone A, an area that has a 1-percent probability of flooding every year and where predicted floodwater elevations have not been established.

Additional information about FEMA’s proposed action, including maps showing the potential impacts on floodplains, may be obtained 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 within 15 days after publication of this notice.