DR-4558-CA Initial Public Notice 001

INITIAL PUBLIC NOTICE: MCSD WATERMAIN MAD RIVER CROSSING RETROFIT PROJECT (PHASE I), HUMBOLDT COUNTY, CALIFORNIA | HMGP 4558-396-059R

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 McKinleyville Community Services District (MCSD) in Humboldt County, California, to provide topographic surveys, engineering design, and special studies in order to create a new, seismically-resilient secondary pipeline under the Mad River. The proposed action would mitigate impacts from earthquakes by providing reliable water infrastructure to meet the full demands of the community and by using a more resilient pipe material to prevent catastrophic failure during an earthquake event. 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 intent to carry out an action affecting a floodplain and wetland.

The purpose of the proposed action is to reduce seismic hazards to a pipeline. The proposed action consists of topographic surveys, engineering design, and special studies relating to the construction of a secondary pipeline under the Mad River. Geotechnical investigations would include installing borings along the proposed alignment to understand soil stability, which would involve ground disturbance. The preliminary survey and engineering design would establish drilling locations, which could be located outside of the MCSD right-of-way, requiring temporary construction easements from adjacent property owners. Drilling would include ten borings extending to depths of 50 to 75 feet and with a diameter between 4 to 6 inches.

The project area is in the 100-year floodplain as depicted on the FEMA Flood Insurance Rate Map (FIRM) Numbers 06023C0687F, dated November 4, 2016. The FIRM shows that the project area lies within Zone AE, an area in the regulatory floodway along the Mad River that has a 1-percent probability of flooding every year and where predicted floodwater elevations are roughly 41 feet.

The U.S. Fish and Wildlife Service National Wetlands Inventory map shows several different potential wetlands within the project area. There are freshwater forested/shrub wetlands along the Mad River within the proposed pipeline alignment where geotechnical borings may be drilled. As geotechnical borings would be drilled within the river and on the riverbeds, impacts to wetlands are possible.

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.