Efficient Patterns Of Conservation Activities In A Watershed: The Case Of The Grande Ronde River, Oregon

This research examines a spatially explicit allocation of habitat restoration activities in an Oregon watershed to meet water temperature targets for the benefit of endangered salmonid fish species. Integrating hydrological, biological and economic models, a series of optimization problems are investigated for different policy targets including temperature reductions and enhanced fish populations. Results indicated that the heterogeneous nature of riparian conditions and stream morphology needs to be considered if restoration activities are to be allocated efficiently in a watershed. We also found that it is less costly to implement restoration activities in tributaries if the objective is to maximize stream length where water temperatures decrease by a certain degree. Although temperature reductions are primarily achieved by shading in nearby reaches, if a desired level of temperature reductions increases, then it is necessary to apply restoration efforts in remote reaches.