Rogue Estuary TA 2022

Estuaries are listed as an Oregon Conservation Strategy Habitat, and the Rogue River Estuary is specifically listed as a Conservation Opportunity Area within that strategy. Estuaries provide an essential nexus for a variety of freshwater and saltwater species. This project addresses two locations - Elephant Bar and Saunders Slough, which are located on the south side of the lower Rogue River estuary, and adjacent to the town of Gold Beach, in Curry County.

This type of rearing, shallow water environment provides critical over-wintering habitat for coho salmon, and rearing habitat for steelhead, cutthroat, Pacific lamprey, and Chinook salmon (many listed are Oregon Conservation Strategy Species). ODFW Biologists have also identified these areas as having high intrinsic potential for coho salmon production. Due to the high intrinsic potential of the area for anadromous fish production and the need to improve stream complexity, the Rogue River Estuary Strategic Plan (LRWC, 2015) identifies this area as high priority for restoration. In addition, riparian areas are mainly composed of small shrubs and hardwoods and lack large conifers needed for future contributions of large wood to the estuary.

The request for technical assistance is to fund a hydrologic model with existing datasets, a design for a restoration plan, review of cultural resources, identify necessary permits, and draft construction implementation estimates. We plan to contract with a firm to do this work.

Project partners include private landowners, ODFW, and BLM.

The goal of the project is to create an estuary restoration design, which will increase suitable year round habitat for all freshwater life stages of coho and other native salmonids by 7.5 acres, while also supporting channel/floodplain processes that will benefit other native aquatic species. This open water and seasonally inundated habitat is extensively used by migratory waterfowl, red-legged frogs, beaver, native salmonids, and other fish. Estuarine habitats are already extremely limited in the Rogue River Estuary, and these important habitats provide rearing areas not only for salmonids, but also for species like eulachon, Pacific lamprey, and green and white sturgeon. Growth rates for juvenile coho salmon in estuaries have been shown to increase with time spent in estuaries rearing, and larger smolts have a greater chance of survival as returning adults.

Through this Technical Assistance grant the proposed design would lead to the addition of large wood placements in the slough, and to the rearing floodplain areas to help restore habitat quality and natural processes to the system by increasing productivity through increased organic matter and nutrient retention leading to increased invertebrate secondary production. The large wood will also provide pools that afford critical hiding and resting areas for fish, which are especially important fish habitats during periods of low streamflow. During high flow events in the winter, water flowing over and under logs can result in localized scour pockets or holes, providing excellent cover habitats for fish, as well as low velocity refugia.

The proposed sites are located within area of relatively high coho habitat intrinsic potential determined by NOAA and ODFW. The restoration actions supported by the deliverables identified in this Technical Assistance grant will reconnect and enhance degraded off-channel habitats, add large wood to the stream/slough channels and floodplains for shorter term habitat structural complexity, and revegetate sites to promote long term recovery and functionality of riparian areas, floodplains, and fluvial processes. The eventual implementation work should benefit salmonid populations by increasing access to high quality summer and winter rearing habitat. There are also plans to enter the restoration area on Elephant Bar into a conservation easement following the implementation, allowing additional protections.