Steady-State Water Quality Modeling in Streams

A general mathematical model for simulation of conservative and nonconservative constituents in streams and rivers is developed. Mass transport of constituents is accomplished by advection and biochemical reactions. The models simulate the interaction of the dissolved-oxygen resources of the water system with the nitrogen cycle, chlorophyll a, and carbonaceous biochemical oxygen demand. Also, conservative substances and phosphorous uptake by algae and coliforms are simulated by the model. The results of applying the model to the Truckee River system in northern California and Nevada are presented. The model has demonstrated the ability to simulate historical water quality conditions and to be a flexible easily adaptable planning tool.