Publication Summary

The 303(d) listings for temperature in streams in the Wind River basin include Bear Creek, Eightmile Creek, and Trout Creek. Temperatures in the lower portion of Trout Creek have frequently been measured near or above the lethal limit for steelhead of about 24 degrees C.

This technical assessment uses effective shade as a surrogate measure of heat flux to fulfill the requirements of the federal Clean Water Act Section 303(d) for a Total Maximum Daily Load for temperature.

The Wind River watershed covers 582 km2 and supports a fifth-order stream system that discharges to the Columbia River near the town of Carson, Washington. The 303(d) listings for temperature in streams in the Wind River basin include Bear Creek, Eightmile Creek, and Trout Creek. Temperatures in the lower portion of Trout Creek have frequently been measured near or above the lethal limit for steelhead of about 24 degrees C.

This technical assessment uses effective shade as a surrogate measure of heat flux to fulfill the requirements of the federal Clean Water Act Section 303(d) for a Total Maximum Daily Load for temperature. Effective shade is defined as the fraction of incoming solar shortwave radiation above the vegetation and topography that is blocked from reaching the surface of the stream.

In addition to the load allocations for effective shade, other management activities are recommended for compliance with water quality standards for water temperature, including measures to reduce channel widths and water withdrawals.