Palouse Environmental Update

By David Hall, Environmentalist Community Member

The Palouse Basin Aquifers: Our Municipal And University Water Use Is Unsustainable

As many here know, the City of Moscow and the University of Idaho get much of their water from the ancient and pure Grande Ronde aquifer. The City of Pullman and Washington State University get all of their water from the Grande Ronde. Historically the Grande Ronde aquifer water level has been dropping almost a foot a year–a 22-foot decline since 1992. It is illegal in both Washington and Idaho to mine groundwater (to use more water than is being recharged naturally)—but that is just what we have been doing in the Palouse basin.

There used to be at least one artesian well in Pullman. No more. The Grande Ronde aquifer recharges extremely slowly, if at all. The City of Moscow and the UI also get water from the shallower Wanapum aquifer, which does recharge. But its supply is insufficient for the needs of the basin. The UI does make use of quite a lot of water reclaimed from the City of Moscow’s water reclamation and reuse facility.

Five decades ago, in 1967, the Palouse Basin Aquifer Committee (née Pullman Moscow Water Resources Committee) was formed, under the direction of Washington and Idaho’s water agencies, to find a way to a sustainable water supply for the Palouse Basin. Recently the state agencies have indicated that, while headway has been made through studies and conservation, the solution is not in view.

Moscow, Pullman, the UI, and WSU have generally made great strides in conserving water. And while conservation is very important, we cannot conserve enough water to stop the mining of the Grande Ronde aquifer. We need to augment our supply of water in some manner.

The 13th annual Palouse Basin Water Summit will have a presentation by the Palouse Basin Aquifer Committee (PBAC) of their four top contenders for providing a more sustainable water supply for the basin. All four offerings presented by PBAC involve using surface water in some fashion. (See accompanying articles.)

Another option is to treat some of our wastewater. Two years ago Dr. Greg Möller (UI Professor of Environmental Chemistry and Toxicology) spoke at the Palouse Basin Water Summit about his wastewater to tap water system, N-E-W Tech™, and he demonstrated it at the Moscow Waste Water Treatment Plant. To read about his system, visit

I recently listened to a presentation on Sea Change Radio about Orange County’s waste to tap water treatment system. The General Manager of the Orange County, California, Water District discussed the innovative technology the district uses to clean its wastewater, and examined the costs compared to other alternatives. (See

Both of these options should be considered here, as should increased water reuse in the basin. Aquifer storage and retrieval (ASR) should not be considered for the Grande Ronde aquifer, as the risks are too high.

Palouse Basin Water Summit

Learn more about our water, our most important natural resource, at the Palouse Basin Water Summit on Wednesday, October 19, from 4:30-8:30 p.m., at the Schweitzer Event Center, at 1825 Schweitzer Drive in Pullman. An agenda can be found at Online pre-registration is requested, but admission is free and attendees are welcome to come and go.

Presentations will include the following: The Palouse Basin Aquifer Committee’s four top contenders for providing a more sustainable water supply for the basin by Ben Floyd; an update on the geology of the basin by Dr. John Bush; the Annual State of the Basin and Palouse Basin Aquifer Committee Annual Pumping Report by Korey Woodley; and more. The final presentation will be a keynote address by Patricia Mulroy (Senior Fellow for Climate Adaptation and Environmental Policy, Boyd School of Law, at the University of Nevada–Las Vegas, and former General Manager of both the Las Vegas Valley Water District and the Southern Nevada Water Authority).

In addition, there will be a drawing for a low-flow toilet (courtesy of McCoy Plumbing), and an individual Wisescaping® plan (courtesy of Anatek Labs). Expect a free buffet for attendees–and beer and wine will be available for purchase.

Palouse Basin Aquifer Committee’s Water Supply Alternatives

The Palouse Basin Aquifer Committee (PBAC) has identified four top solutions to meeting both the short- and long-term water supply needs of the Palouse region. The options presented by PBAC are based on revisiting all of the past studies that they could find (about 40) and carefully re-evaluating and comparing them. They winnowed those down to about 15 and then settled on four packaged project alternatives.

 Alternative 1 – 1,967 million gallons per year (MGY) (85 percent of the 2,324 MGY target); estimated capital cost 78 million dollars.

  • Direct diversion, treatment, and delivery of water from the Snake River to Pullman, WSU, Moscow, and UI.

Alternative 2 – 1,908 MGY (82 percent of the target); $60 million cost.

  • Direct diversion from the North Fork Palouse River, and pump, convey, and deliver treated water to the City of Moscow and City of Pullman water systems.
  • Direct diversion from Paradise Creek or the South Fork Palouse River, treat, and actively inject treated water to aquifer recharge wells in Moscow.

Alternative 3 – 2,324 MGY (100 percent of the target); $86 million cost.

  • Build a storage reservoir on Flannigan Creek, pump and convey water to Moscow, treat, and deliver to the City of Moscow and UI water systems.
  • Capture runoff from the South Fork Palouse River for treatment and direct use in the Pullman and WSU systems.

Alternative 4 –1,893 MGY (81 percent of the target); $73 million cost.

  • Direct diversion on Paradise Creek, treat, and actively inject treated water into recharge wells in Moscow.
  • Direct diversion from South Fork Palouse River in Pullman, treat, and actively inject treated water into aquifer storage and retrieval (ASR) wells in Pullman. A variation of this project could include direct use of treated water to the City of Pullman system without ASR.
  • Upgrade the Pullman wastewater treatment plant to produce reclaimed water for use within Pullman and WSU.
  • Use additional reclaimed water from the Moscow wastewater treatment plant. Infiltration basins would be constructed to provide for passive infiltration of reclaimed water into the Wanapum aquifer.
  •  Increase conservation to 15 percent additional savings beyond the baseline projection


Learn more about these alternatives at the Palouse Basin Water Summit on October 19 at the Schweitzer Event Center in Pullman.

New Wisescape® Book Available

The brand new book Wisescape® Guidebook: Water-Efficient Landscaping on the Palouse, produced as “A Partnership of the City of Moscow and the City of Pullman,” will be available at the Palouse Basin Water Summit. Learn how to use less than half the water a lawn uses by converting your turf to an eye-catching Wisescape®. This guidebook, specific to the Palouse region, presents a variety of native plants and ornamental plants.

Both Moscow and Pullman have rebate programs for property owners who transition from irrigated lawns to Wisecaping.

David Hall is a board member of the Palouse Prairie Foundation, Paradise Ridge Defense Coalition, and Palouse Water Conservation Network.