Instream Flow Modeling to Support Hydroelectric Plant Permit Application

Pitkin County required technical services to understand both the water rights and instream flow impacts of various operations of a proposed hydroelectric plant on Castle Creek. The project team developed a model to analyze optimal hydroelectric operations based on existing water rights and historic streamflow. Once the model operations had been confirmed, the team developed and ran many test cases to optimize power production while maintaining instream flow. Ideal instream flow targets were based on results of existing R2CROSS analyses as well as stream levels deemed acceptable by the community.

Once the optimization process was completed, it was the job of the project team to effectively communicate the stream impacts to the client. Using the Indices of Hydrologic Alteration (IHA) protocol, details of the changes in streamflow regime were presented in a manner more understandable to the general public.