A Statistical Model for Estimating Stream Temperatures in the Salmon and Clearwater River Basins, Central Idaho

A water-quality standard for temperature is critical for the protection of threatened and endangered salmonids, which need cold, clean water to sustain life. The Idaho Department of Environmental Quality (IDEQ) has established temperature standards to protect salmonids, yet little is known about the normal range of temperatures of most Idaho streams. A single temperature standard for all streams does not take into account the natural temperature variation of streams or the existence of naturally warm waters. To address these issues and to help the IDEQ revise the existing State temperature standards for aquatic life, temperature data from more than 200 streams and rivers in the Salmon and Clearwater River Basins were collected. From these data, a statistical model was developed for estimating stream temperatures on the basis of subbasin and site characteristics and climatic factors.

View Water-Resources Investigation Report 02-4195 PDF (1.5 MB)