Publication Summary

This report describes the 1995-2000 water temperature results for monitoring conducted in the Chehalis River basin.

This report describes the 1995-2000 water temperature results for monitoring conducted in the Chehalis River basin.

Results are presented for long-term temperature monitoring in the upper Chehalis basin. The five monitoring sites were near the mouths of four tributaries to the Chehalis River -- Black River, Lincoln Creek, South Fork Chehalis River, Newaukum River -- as well as in the mainstem Chehalis River upstream of the Newaukum River. All sites showed water temperature violations, with three of the five sites exceeding 25 degrees C. Recommendations include continued monitoring and implementation of basin-wide riparian restoration activities.

Results are also presented for monitoring to determine the effectiveness of riparian shading practices in reducing water temperature. Results represent pre-shade conditions. Upstream and downstream sampling was conducted at seven monitoring sites: Mill Creek, North Fork Lincoln Creek, a tributary to Mohney Creek, south tributary of Salzer Creek, South Branch of Big Creek, Stillman Creek, and a tributary to Scatter Creek. Results show higher water temperatures downstream for most of the pre-restoration sites. Continued water temperature monitoring is recommended after riparian plantings have become effective in providing shade to the stream.