Agreement with Metropolitan and MWDOC, (Coordinated Operating Agreement, see “Available Supply Coordination: Water Banking” section below). IRWD is involved in numerous programs to help reduce dependence upon imported water (the most expensive source). These programs may influence the timing of the various sources and supply availability. Please see “Description and Quantification Section” below for more detail on individual supply sources. Available Supply Coordination: OCWD & Groundwater For groundwater supplies, coordination efforts are implemented with OCWD, which manages the Orange County Groundwater Basin (Basin). Approximately 50 percent of IRWD’s overall supply comes from its groundwater wells in the Basin. Each year OCWD sets a target amount of pumping and establishes a Basin Pumping Percentage (BPP) for the groundwater producers. The BPP is the ratio of groundwater production to total water demands expressed as a percentage. To discourage pumping above the established BPP, any groundwater production above the BPP is charged a Basin Equity Assessment (BEA) which is set so that the cost of groundwater pumping is similar to the cost of imported water. Some of IRWD’s treated groundwater supplies are exempt from the BEA. The majority of the potable groundwater used by IRWD is produced from its Dyer Road Well Field (DRWF) located in the City of Santa Ana. The DRWF consists of 16 wells that pump from the clear water zone of the Basin and two wells (with colored-water treatment facilities) that pump from the deep, tinted-water zone of the Basin. The tinted-water portion of the DRWF is referred to as the Deep Aquifer Treatment System (DATS). Through an existing agreement, the DRWF production is limited to 28,000 AF per year (AFY) consisting of 20,000 AFY of clear groundwater and an additional 8,000 AFY of “matching” clear groundwater, provided a minimum of 8,000 AFY of colored groundwater is pumped from the deep aquifer zone. Available Supply Coordination: Metropolitan & MWDOC (Imported Water) IRWD receives imported water through MWDOC. MWDOC is a wholesale member agency Metropolitan. IRWD submits imported water supply requests to MWDOC, which then incorporates the request into a regional order of water for imported supplies to Metropolitan. Both Metropolitan and MWDOC provide wholesaler information indicating their ability to meet IRWD anticipated imported water demands. Metropolitan and MWDOC both state in their UWMP and WSCP that these imported supplies are reliable through multiple, consecutive years of drought. The wholesale agencies are also involved with coordination of deliveries from IRWD’s Water Banking Program to be used in the event of imported water shortages. Available Supply Coordination: Water Banking IRWD has diversified its water supply reliability by developing cost effective water banking projects, as emergency storage, in Kern County, California. IRWD has constructed a fully operational Water Banking Program that makes it possible for IRWD and its banking partners to store excess water during “wet” hydrologic periods. The stored water is then available for use
WSCP - 17
IRWD – 2025 Water Shortage Contingency Plan
Powered by FlippingBook