Jacoby Creek Estuary Project

Estuarine Habitat Connectivity for Fish and Flood Control Project

Completed: 2019

Overview

  • Restore roughly 16 acres of former grazing pasture to estuarine conditions.
  • Installed habitat features within the estuary to support sensitive species like salmonids and tidewater goby.
  • Constructed features to assist salmonids in reaching the Gannon Slough system or lower Jacoby Creek if they were washed out of Jacoby Creek during flood events.
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History/Location 

This project area neighbors the USFWS Humboldt Bay Wildlife Refuge, the 225-acre Arcata Marsh and Wildlife Sanctuary, the 508-acre California Department of Fish and Wildlife (CDFW) Mad River Slough Wildlife Area, and the Jacoby Creek Land Trust property. Most of this region was once tidelands but now supports grazing and agricultural uses with residential farmhouses, zoned for agricultural and natural resource purposes.

The Jacoby Creek Estuary and Gannon Slough Tide Gate Replacement is a vital part of the Arcata Baylands Acquisition and Restoration Project, establishing connectivity across more than 1,300 acres of local, state, and federally protected lands along Humboldt Bay's northern edge. 

Restoration Enhancements

The focus of the Jacoby Creek estuary project was to restore roughly 16 acres of former grazing pasture to estuarine conditions. This was achieved by removing around 500 feet of the existing Jacoby Creek levee and constructing a new setback levee, enabling freshwater to flow into the estuary area during high tides and storms. A new 'fish-friendly' tide gate was also installed within the estuary to allow a muted tidal flow into an adjacent Gannon Slough channel. An existing Gannon Slough tide gate was replaced, and two new culverts were added to reconnect other remnant channels to the Gannon Slough complex. A channel extending from the new estuary tide gate to a remnant south Gannon channel was constructed to facilitate hydrologic connectivity during flood events and improve flood control for nearby agricultural lands. The project also included installation of habitat features such as large woody debris, low volume pools, and meandering channels within the estuary footprint to support sensitive species like salmonids and tidewater goby (Eucyclobobius newberryi).

The project was designed to assist salmonids in reaching the Gannon Slough system or lower Jacoby Creek if they were washed out of Jacoby Creek during flood events. Post-storm fish sample events, conducted by CDFW and City staff, have confirmed the project's success in protecting salmonids during storms, with substantial detections of young Coho salmon (Oncorhynchus kisutch) within the estuary. 

Partnership and Funding

City of Arcata.