Reclamation Information Sharing Environment (RISE)

The Deschutes River flow can be characterized as dominated by groundwater discharge. Prior hydrologic modeling studies have not produced simulated streamflow of adequate quality. This scoping study explores a modeling approach similar to that taken in the recent St Mary and Milk River Basin Study Update, which includes a precipitation-runoff model with routing module that represents both a storage term that simulates the quick component of the runoff, as well as a lower storage term which describes the slow component of the runoff and the groundwater extraction and losses. This scoping study also explores an annual lagged precipitation-streamflow model. Both of these simple hydrologic modeling approaches reasonably simulate unregulated streamflow at three case study locations, including the Deschutes River below Crane Prairie Reservoir, the Crooked River near Prineville, and the Deschutes River near Madras. The methods show that a simple modeling approach may out perform more complex methods have that have historically been applied in the region.