Stream resource managers need to be able to determine the relationships between flows and various fish habitat parameters in order to evaluate the effects of a present or proposed project which can alter flow regimes. A technique was developed which uses field measurements and a digital computer to quantitatively express the relationships between streamflow and available food producing, spawning, resting microhabitat, and cover areas for trout. Changing a few weighting factors can adapt the program to various species of salmonids. An example of a plot of study results utilizing this methodology is presented. A discussion of the benefits from application of the methodology to release flow evaluations is given.