Predicting Channel Responses to Flow Diversions

potential to adversely affect the recreational, aesthetic, and ecological resources of mountain streams. The ability to predict channel response to flow diversion can help project designers minimize adverse impacts and design appropriate mitigation measures. Toward this end, we use insights gained from detailed case studies of Lake Fork and Rock Creek – two diverted streams in the Uinta Mountains, Utah – (Stamp 2000, Stamp and Schmidt 2000, Schmidt et al. 2005), in conjunction with the results of previous studies, to develop a conceptual framework for predicting channel response to flow diversion. Specifically, we present a classification of different types of diversion systems and compare their effects on downstream hydrology and sediment supply. We then provide a description of the geomorphic, climatic, and watershed characteristics that affect how alterations to the flow and sediment regime ultimately translate into changes in channel morphology. This conceptual framework for predicting channel response to flow diversion is applicable to common types of municipal and agricultural diversion systems on mountain streams in the Intermountain West wh er e r un o f f pa t t e rn s a re predominantly snowmelt-driven.