The Integrated Resources and Planning Distribution System Model (IRPDSM)  model was originally developed by DCSE in 1998 to assist one of California’s largest Water Districts to improve its operational policies to size future facilities, and in analyzing alternatives in the Integrated Resource Plan.

This model is a comprehensive resource and supply distribution system model which simulates and optimizes deliveries and storage of imported water through water distribution system.  The model accounts for regionally coordinated local water supplies and storage of imported water in local groundwater basins and the hydraulic and storage constraints that limit the movement of water through the distribution system.

IRPDSM has been used by IRWD to identify water sources, storage reservoirs, and connections between the different pressure zones, demand nodes, pumping capacities, and pipe sizes; the model uses the representative schematic to deliver water to meet demand up to the limitations of the existing system to convey the water.

By analyzing the IRPDSM model run results, IRWD staff is able to create demand shortage reliability curves due to different mix of water supply sources.  The model can provide information to identify demand zones within the system that could suffer significant supply deficit if one or more of supply sources were to be reduced or shut down.  Not only can the IRPDSM model identify demand shortage coming from supply sources deficit, but also determine the demand shortage is due to hydraulic capacity limiting the water from the alternative source to the area of demand.