Pacific Northwest Research Station

Entiat Watershed Restoration

This economic recovery project, led by Karl Polivka of the PNW Research Station, deals with aspects of salmon habitat restoration effectiveness in the Entiat River watershed, a low-rainfall area in the Columbia Basin subject to wildland fire and drought conditions typical of the dry interior West. The work is being accomplished through a joint venture agreement with the Cascadia Conservation District (CCD). The resulting analyses will be made available for use by land and fisheries managers for planning and monitoring for habitat protection and restoration efforts.

The CCD used economic recovery funds to hire and house field and laboratory workers who gather and analyze data on the effectiveness of instream habitat structures in the Entiat watershed. The techniques employed are intended to yield direct estimates of the benefits of restored habitat structures to fish production, and allow greater precision in the estimate of variability instream carrying capacity than normal monitoring procedures. The work supports the roll-up of reach-level information to sub-basins, and helps researchers who use models to refine predictions of fish population responses to environmental fluctuations including climate change, supplementation, natural disturbance, and restoration actions.

The Entiat Watershed Planning Unit (WPU) is an association of resource specialists, local, state and federal agencies, and landowners who seek an informed approach to balancing the competing interests at stake within the watershed. Over the last decade, the Entiat WPU has advanced the goals of seeking restoration of depleted salmon stocks, restoring aquatic and riparian function, and meeting the needs of growing human activity in the Entiat River basin in Chelan County, Washingon. The CCD has facilitated the efforts of the Entiat WPU, in part by endorsing several instream habitat restoration projects, including linking project sponsors with funding agencies and obtaining landowner approval for implementation.

The project enables CCD to have a direct assessment of the effectiveness of restoration actions that inform their reports to the Entiat WPU and other interested parties. The information gained from this collaboration enables CCD to meet its obligation of accountability to the community of stakeholders in the Entiat River Basin by reporting on the effectiveness of restoration actions that CCD has sponsored.

In 2010, sampling was carried out in the lower Entiat River at microhabitats where restoration structures were present or absent. Technicians used snorkeling to count Chinook and steelhead, and evaluated the condition of fish they captured. They also made measurements of physical habitat parameters to analyze relationships between habitat conditions and fish numbers and health. The data were analyzed, and a report on results so far was prepared. Polivka is finding that the two types of fish appear to respond differently to restoration structures, with steelhead seeming to benefit more than Chinook. Mark and recapture studies indicate that growth of steelhead is higher at sites that contain structures. However, results are still preliminary, and additional sampling is expected to clarify the observations and help explain the causes and covarying factors.