Describing aquatic habitat is complex as it is the result of the blending of physical, biological, and chemical variables. Providing and maintaining suitable water quality, most notably temperature, is particularly essential for the fishery resource to fully utilize the aquatic habitat available to them. In the Sultan River, this is especially important in light of the recent re-introduction of Chinook, coho, and steelhead with the completion of fish passage at the Diversion Dam, which allows unfettered access to the upper reach of the river. The conditioning (blending and mixing) of waters of varying temperatures is expected to result in a more normative water temperature regime (similar to the temperature regimes further downstream in Reaches 1 and 2). Conditioning will stimulate primary productivity, increase macroinvertebrate production, improve fish growth, expand fish distribution and add resiliency to the fish population by enhancing fish survival in Reach 3. Monitoring of the biological response to conditioning will be used to help verify that this measure is meeting the intended goals.