How ASR can benefit Hillsboro
Hillsboro Water (HW) depends on the Tualatin River for its water supply the majority of the year (approximately from November to June). HW typically uses about 14 million gallons a day (MGD), but during the summer months that demand almost doubles (due to outdoor irrigation), and use can approach 25 MGD. Unfortunately, the river supply runs opposite of demand. During the months of lowest demand, especially late winter/early spring, supplies are plentiful and rainfall and runoff can be so heavy that the river overflows its banks. Very little of the river water can be stored so it just flows away. Then summer comes around and the river drops. Hillsboro and its water supply partners must release water that has been stored in Hagg Lake and Barney Reservoir to meet demand.
The development of ASR wells will allow Hillsboro and its Joint Water Commission (JWC) partners to inject some of the excess winter flow into the ground and then pump it out in the summer when the river is low. This will become a critical supply once Hagg Lake and Barney Reservoir no longer store enough water to meet summer demands of all JWC customers.
The JWC has identified aquifer storage and recovery as a potential "bridge" to their water supply needs. Estimates indicate that potential exists to develop an ASR program that could provide the JWC service area, including Hillsboro, up to 18 million gallons of water per day. The objective of Phase One of the program is to identify optimum test well locations, conduct well testing, and prepare facilities plans for three ASR wells. Subsequent phases of the ASR Program would seek to expand the overall system capacity by installing additional wells.