A water temperature study in geothermally active areas of Big Sulphur Creek was conducted to evaluate the suitability of habitat for juvenile steelhead trout. Portions of the Big Sulphur Creek drainage have been classified as lethal, marginal, or satisfactory based on a comparison of recorded temperatures and a review of literature concerning the effects of high temperatures on steelhead. Results indicate that stream temperatures in 4.1 miles of Big Sulphur Creek between The Geysers geothermal energy development and Squaw Creek increase to lethal levels during the summer months due to natural geothermal activity and reduced streamflow. Few steelhead have been collected in this area. Stream temperatures in Big Sulphur Creek upstream from natural geothermal activity and in Squaw Creek remain at satisfactory levels through the summer. Numerous steelhead have been collected in these areas and in Big Sulphur Creek downstream from Squaw Creek.
|
