FLUVIAL GEOMORPHOLOGY AND INSTREAM FLOW WATER RIGHTS

It is well understood that the physical characteristics of the stream channel define the aquatic habitat and streamflows and movement of sediment are very important secondary factors. An instream flow water right is an allocation of water to the aquatic ecosystem. Methods based on an analysis of streamflows ignore the possibility of channel change although there is an implication that channel change is considered in any hydrologic analysis made to determine an instream flow water right that includes an analysis of annual peak flows. Physical habitat analysis also mostly assumes the channel does not change with changes in water management. Two elements of fluvial geomorphology are considered herein- peak flows and sediment transport. Peak flows were important in establishing insteam flow requirements for a project on the Terror River in Alaska. The need to move sediment and limit deposition in spawning redds of salmon and trout during the incubation as part of the incubation criteria used in physical habitat simulation. Sediment transport factors have been used in planning but appear not to be considered in the actual establishment if an instream flow right. Attempts to used peak flows in the process of allocation of water to instream flows have been made in Colorado but have not been successful. One of the purposes of the presentation is to ask for help in location studies that may have used fluvial geomorphology in the determination of a water right. Studies for water right determinations are no done for publication in academic journals which makes it difficult to locate them.