Garcia River Estuary Enhancement Project

Garcia River Estuary Enhancement Project

The Project will restore complex salmonid rearing habitat in the 0.5-mile-long middle estuary zone of the Garcia River. The interface between fresh water and saline tidal inflows in the middle estuary provides the food-rich environment and water quality conditions that salmonid smolts need during their biophysical transition to the ocean. The Project’s goal is to create sufficient winter and spring rearing habitat in the middle estuary to support up to 54,000 juvenile coho and provide winter rearing habitat commensurate with the watershed’s summer rearing capacity. Ultimately, the Project is estimated to provide winter/spring habitat for approximately 68,000 coho juveniles. Currently, the Garcia River is disconnected from the adjacent floodplains except during large storm events, when it is only connected for a few hours during each flooding event. This inundation pattern does not provide the long-duration inundation needed to develop primary and secondary biotic productivity on the floodplains, nor does it provide the floodplain connectivity that juvenile salmon need during winter and spring flows to seek refuge from high velocities and take advantage of the food-rich wetlands. Hundreds of juvenile salmon (coho, Chinook, and, steelhead) have been observed congregating in and feeding from two small log debris jams in the estuary that have subsequently broken apart, leaving no complex shelter for juvenile salmonids to use during their critical estuary rearing period. With no in-stream shelter and little high flow refugia, juvenile coho and other salmon are vulnerable to high rates of predation and limited feeding opportunities in the Garcia River estuary, which severely limits the recovery potential in this critical coastal watershed that hosts one of the region’s few remaining independent wild coho populations. The Project aims to address restore complex rearing habitat by 1) re-connecting and re-creating two seasonally flooded accessible wetlands on the floodplains in the National Monument to provide long-duration inundated habitat for high flow refugia and floodplain feeding opportunities, 2) installing ten engineered log jams and six habitat structures to provide complex low-flow shelter elements that juvenile salmon need during their estuary rearing period, and 3) installing two engineered log jams to guide the river and create complex flow paths and connectivity to the floodplain inlets and habitat structures.

Point Arena

Mendocino

Unincorporated

Mendocino