One of the main goals of the RiverWare modeling system is to provide a way to express operating policy separate from the physical process model. Many older basin management models were dedicated software—they integrated complex operating policies into the code, intermingled with the code for the physical processes. This allowed ultimate flexibility and detail for the operations. Typically, general modeling tools allow only the specification of simple policies like guide curves.

RiverWare allows complex policies to be expressed in a general modeling framework. RiverWare achieves this through the RiverWare Policy Language (RPL), which the modeler can use to express policy. The policy statements are interpreted at runtime, and the policies interact with the simulation to drive the solution.