Final Public Notice: Eureka Flood Reduction Project (Phase 2)

FINAL PUBLIC NOTICE
EUREKA FLOOD REDUCTION PROJECT (PHASE 2)
HUMBOLDT COUNTY, CA
HMGP-4344-503-013R

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 Eureka (Subapplicant) in Humboldt County, CA, to mitigate flood risk by upgrading existing pipelines and installing new storm drains near low-lying, flood-prone residences and businesses in the West Side Eureka sub-watershed near Humboldt Bay. Pursuant to Executive Order 11988 (Floodplain Management), Executive Order 11990 (Protection of Wetlands), 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 risk. The Proposed Action consists of: 1) upsizing approximately 3,200 feet of existing storm drains with larger capacity pipes ranging from 18 to 36 inches in diameter; 2) installing 3,700 feet of new storm drain, ranging from 36 to 60 inches in diameter, and box culverts ranging from 8-foot by 3- to 4-foot; 3) placing up to 10 low impact development (LID) features (e.g., rain gardens) along or upstream of storm drain improvements (maximum area per LID feature is anticipated to be 10 feet by 15 feet with a maximum depth of 5 feet); 4) installing 4 trash capture devices upstream of the storm water system’s outfalls that drain to Humboldt Bay, including two vaults and two outfalls, and 5) extending, deepening, and widening of an existing channel that connects Humboldt Bay to Palco Marsh, and depositing beneficial fill excavated from the channel onto low-lying areas of the marsh, which would have the intended effect of restoring historical salt marsh elevations and associated habitat. No ground disturbance would occur within Palco Marsh. The majority of the project would occur within urbanized areas that have been previously disturbed during the initial installation of the existing stormwater conveyance infrastructure.

The project area is depicted on FEMA Flood Insurance Rate Map (FIRM) panel 06023C0845G, effective June 21, 2017. The FIRM shows that portions of the Proposed Action lie within Zone AE, a Special Flood Hazard Area with Base Flood Elevation (BFE) that has a 1-percent probability of flooding every year. The U.S. Fish and Wildlife Service’s National Wetlands Inventory (NWI) Mapper shows that portions of the Proposed Action overlap with estuarine and marine; freshwater forested/shrub; and riverine wetlands.

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.

Two alternatives to the Proposed Action were considered: Alternative 1: No Action; and Alternative 2: Replacing the City’s Entire Storm Drain System. Alternative 1 would result in no action being taken to mitigate flood hazards in the area. This Alternative is not recommended because flooding would continue in the City of Eureka due to extreme weather flooding events, tidal surges, and sea level rise. Alternative 2 would involve replacing the entire storm drain system in the City and upsizing the piping for suggested flood levels. This Alternative is not recommended due to cost and unknown environmental impacts resulting from the age of the storm drain system, which predates the California Environmental Quality Act (CEQA) review process.

FEMA has determined that the Proposed Action is the only practicable alternative available; therefore, the Proposed Action must be located in the floodplain and wetlands. The Proposed Action would have no significant adverse impact on the floodplain or wetlands and would benefit the area by reducing the risk of flooding and flood damage. Minimization of flood risk would be achieved through the Proposed Action by increasing the storm drain system’s capacity and its ability to attenuate storm water during tidal surges and projected long-term sea level rise, and by alleviating overflow during flood events. The City of Eureka 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.