Mad River Estuary Restoration

Mad River Estuary Restoration

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Project Goal:

Restore key salmonid off-channel rearing habitat and provide public access, specifically for angling and river recreational uses in the lower Mad River's simplified estuary. The project includes two primary components: off-channel habitat and public access improvements. The public access will benefit the community by providing ADA access to an overlook and to a river access point. The floodplain enhancement will provide channels and a pond within the floodplain that is designed to support winter rearing coho.

Metrics: 4.25 acres of floodplain restored

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Project Stages

Conceptual Design

Permitting Phase


Estimated Completion Date:


Project Funders

State Coastal Conservancy (SCC)

Fish Affected:

Project Description

The lower Mad River historically had access to a broad floodplain which provided critical rearing habitat for juvenile fish and off-channel refugia. Upstream impacts from land management and infrastructure development have led to sediment and temperature impairments. Lower in the river, levees to protect infrastructure and agricultural properties have disconnected the river from its floodplain. Partnering with the McKinleyville Community Services District, we are reconnecting the lower Mad River to more than 4 acres of floodplain to improve key salmonid habitat. In addition, we will improve the existing trail network to enhance public access for angling and river recreation. Now in 2021, the project is fully funded and will begin implementation of the public access and habitat restoration phases in 2022.

The 9.3-acre project is located on property owned by the McKinleyville Community Services District (MCSD), a public agency who oversees water, wastewater, streetlights, library, recreation, and open space within the community of McKinleyville. The project area is located three miles upstream from the mouth of the Mad River, within the zone of tidal influence. The project area encompasses bluff and floodplain topographic features and is within MCSD’s permitted wastewater facility, which includes 4.3 acres of constructed percolation ponds alongside the river. The habitat restoration project area focal point is a pair of constructed percolation ponds for treated wastewater disposal that are leveed from the river’s floods and ringed with cyclone fencing to prohibit public access. MCSD’s existing percolation ponds will be decommissioned and restored to riparian floodplain habitat. Within the restored floodplain a network of backwater ponds and channels will be provided that perennially connect to the Mad River and provide crucial off-channel winter rearing habitat for coho salmon.

The public access project will directly benefit the residents of McKinleyville, the region, and visitors to the region by providing an informational kiosk, interpretative signage, and universal access for a wide range of users such as casual walkers, hikers, birdwatchers, anglers, and cyclists. The project will also provide a lightly developed boat launch. The proposed trail will connect to School Road Trail and to the popular regional Hammond Trail - a part of the California Coastal Trail - that is used by local residents, Coastal Trail hikers, and touring cyclists.

Project Partners:

NOAA Restoration Center
Northern Hydrology and Engineering
SHN Engineers & Geologists
Chris Turner
Redwood Coast Action Agency
McBain Associates

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