SRP Irrigation System Modeling

The Salt River Project (SRP) is an irrigation water users association that serves approximately 250,000 acres (100,000 hectares) in south central Arizona in the vicinity of the City of Phoenix. When SRP was first developed over a hundred years ago, the service area was nearly entirely farmland or desert. Now it is approximately 85% urban, which has greatly changed how SRP operates and maintains its facilities. To assist in planning for continued changes in operational, maintenance and regulatory requirements, SRP has developed a series of models that are able to forecast land use and water demand, determine where in the system demand will be changing, and determine what water quality effects of well water and different mixes of surface water will be. Several studies have used these models including an available capacity study, well operation and water quality study, well effectiveness study, WTP siting study, and a dilution study for a Generating Station. This paper describes these models and some of the studies that have used them.