Parrish Sprague River Stream Restoration Project - Instream Structures and Spawning Gravel

PROJECT OBJECTIVES:

1. Provide spawning, juvenile rearing, and adult holding/resting habitat on two miles of the Sprague River for Chinook salmon, Steelhead, Redband trout, and other native fish.

2. Aggrade the channel and reconnect the floodplain.

3. Increase hyporheic exchange by raising the water surface throughout the project to promote bank storage and allow for water return during the summer base flow period.

4. Install structures that promote turbulent mixing to oxygenate the water and create refugia.



PROJECT DESCRIPTION:

The Parrish Sprague River Channel Restoration Project is intended to enhance channel conditions on approximately two miles of the Sprague River using low-tech process-based restoration, including floodplain reconnection. Techniques may include BDAs (beaver dam analogs), PALS (post-assisted log structures), LWD (large woody debris) structures, grade control structures, and structures intended to promote turbulent mixing and increased oxygenation. The Parrish Sprague River Channel Restoration Project is located in the middle portion of the Sprague River approximately 0.35 miles downstream of the Sprague River bridge in the town of Sprague River, Oregon (Township 36S Range 10E Section 10; Figure 1).

This project will provide important spawning, juvenile rearing, and adult holding/resting habitat on two miles of the Sprague River for Chinook salmon, Steelhead, and Redband trout. The project will also improve habitat for ESA-listed species c’waam (Lost River sucker) and koptu (Shortnose sucker), and other native species including lamprey and sculpins.

Anadromous salmonids and adfluvial non-anadromous salmonids adult upstream migration is expected to be enhanced by providing large woody debris (LWD) cover along with expected pool deepening via change in structure associated velocity vectors. Spawning and egg incubation are expected to be enhanced through addition of gravel at locations associated with LWD structure placement. Fry colonization and juvenile salmonid rearing habitat will also be improved through woody structure additions.

The project area is a known area of low dissolved oxygen and current fish habitat conditions are poor due to a lack of habitat complexity and shallow water depths associated with a lack of woody vegetation or structure as well as high width-to-depth ratio associated with much of the mainstem Sprague River.

PROJECT BENEFIT:



This project is considered an important step towards achieving the tribal restoration goal of reintroduction and restoration of the Klamath Tribes historic anadromous fisheries that have been extirpated. Specifically, the project will enhance spawning, rearing and holding/resting habitat in the Sprague River to benefit Chinook salmon, Steelhead and other native fishes. The project will address factors limiting the productivity of Chinook salmon and Steelhead necessary for the exercise of native subsistence fishing.



The project will address factors limiting the productivity of Chinook salmon and steelhead necessary for the exercise of native subsistence fishing.