In the Moscow domestic area water is a precious resource. Research to protect the quality water in our aquifer systems is an ongoing venture. While more is learned everyday, there are still many unknowns. The Moscow Water Department is working toward sustainable practices to ensure water will remain as accessible in the future as it is now.
The City of Moscow receives its water entirely from groundwater sources. This means that rather than being supplied with water from a lake or reservoir, we pump water from two main underground aquifer systems, the Wanapum Aquifer System and the Grande Ronde Aquifer System. Contrary to popular myth, aquifers are not underground lake or river systems. Rather, the water in the aquifer systems is located in the cracks, pores, and fissures of the basalt and sediment layers.
The Wanapum Aquifer System is the shallower aquifer system of the Palouse Basin and is found about 60 feet below the surface. This system supplies about 30% of the City of Moscow’s water. Wanapum well levels in Moscow area wells fluctuate some due to pumping and recharge but appear to be quite stable.
The Grande Ronde Aquifer System is the deeper aquifer system of the Palouse Basin and is found at depths below 300 feet, if it is available at all. This system is the main source of water for the City of Moscow and virtually the only source for Pullman and Washington State University.
Recharge and Discharge Rates
Little is known about the recharge and discharge of the Grande Ronde Aquifer System. Research continues on the Palouse to determine the limits of this aquifer system. Historically, regional water levels in the Grande Ronde appear to be dropping at a rate of 1 to 2 feet per year.
The amount of available water in aquifer systems is determined by the rate of recharge and discharge of the system. Unsustainable pumping occurs when the rate of discharge exceeds the rate of recharge. The goal of the Moscow Water Department’s Water Conservation Program is to curb the pumping of Moscow’s wells to sustainable levels.