Back Ground

Water temperature is a critical limiting factor in protecting and recovering federally listed threatened salmonids in Southeastern Washington. Salmonids exposed to water temperatures in excess of 18ºC over prolonged periods experience reduced growth and survival. In the October 2005 Snake River Salmon Recovery Plan the desired future condition for Joseph Creek suggests a 40% restoration of natural condition. A stream flow and temperature monitoring station has been in place in lower Joseph Creek (RM 2.5) since June 2003 (Latitude 46° 01' 46' N, Longitude 117°00' 57" W). This station indicates temperatures continue to exceed healthy condition. Riparian restoration work has been used to improve water temperature in other river reaches in southeastern Washington. This method is currently being used on Joseph Creek however, the majority of the watershed is located outside the jurisdiction of the State of Washington. This study will focus on pinpointing and identifying river reaches that exhibit excessive temperature gain.

Basin

The Joseph Creek Basin originates in Wallowa County, OR, north of the Wallowa Mountains and drains into the lower reach of the Grande Rondo River. Much of the upper river has not been developed and is roadless. The lower 4.5-5 miles has a developed road and has been modified to accommodate agriculture and travel. Riparian habitat in the roaded reach has been modified and reduced to as a result of management practices. The roadless reach appears to have intact healthy riparian as determined from satellite imagery viewed in GIS.


Project Description

This project will be a water temperature assessment using onset temperature data loggers. Data recorders will be place in-stream as soon as stream flows allow access. The objective of this project will be to identify river reaches that exhibit elevated temperature gain. Reaches are being selected based on riparian conditions to identify reaches for restoration. Data will be recorded hourly from initiation through fall when air temperature decrease and high water temperatures are observed to be receding at WDOE telemetry site.