A report by scientists with Washington State University’s State of Washington Water Research Center could help inform decision makers and planners in watersheds across the state, as they develop projects that balance growth with the needs of threatened salmon and steelhead.

Mandated by a recently passed law addressing the effects of small rural wells on stream flows and fish, a WSU-led team of experts from around the state worked for more than a year alongside Washington’s Department of Ecology to develop technical guidance for watershed planners in 15 of Washington’s 62 Water Resource Inventory Areas, or WRIAs.

“We’ve tried to open up the assessment toolbox, to place management decisions in a more contemporary, comprehensive scientific framework,” said Stephen Katz, project lead and associate professor at WSU’s School of the Environment. “Our guidance highlights available approaches that can benefit endangered species and their habitat, as well as Washingtonians’ increasing need for high-quality water.”

The team’s final report, titled “Technical Supplement: Determining Net Ecological Benefit,” is included in the Department of Ecology’s “Final Guidance for Determining Net Ecological Benefit,” which was published July 31, 2019. The document provides a framework for watershed planners to develop proposals that offset the effects of rural wells on stream flows, and for state ecologists to gauge the merits of those proposals.

Connection between wells, streams

Closeup of Jonathan Yoder.
Jonathan Yoder

“There’s a connection between the water you use at home and the water in streams and rivers,” said Jonathan Yoder, project team member and director of the Water Research Center. “Water drawn from wells can affect the amount of water in our streams, which support fish, wildlife, recreation, and people.”

Historically, small rural wells, also known as permit-exempt wells, were scarcely considered in regional water budgets, as they drew so little water and put much of that back into the ground and rivers. Recent court decisions, however, have prompted more careful consideration.

“Our research is grappling with the problem that small wells can have important aggregate impacts,” Yoder said. “When a lot of people move into rural areas, those impacts can add up.”

Responding to the Washington Supreme Court’s 2016 Hirst Decision, the state’s 2018 Streamflow Restoration law seeks to restore stream flows and help support salmon populations while ensuring water for rural residents.

A toolkit for planners

Under the law, the 15 WRIA local planning groups must develop watershed plans that show an overall net ecological benefit from new wells over the next 20 years. The state legislature also seeks to appropriate $300 million in competitive grants for projects that improve stream flows in all WRIAs statewide.

The guidance document lays out steps for determining ecological benefits, discusses issues in measuring and monitoring, and includes five different assessment methods and a decision tree to help planners determine their best approach.

Closeup of Stephen Katz.
Stephen Katz

“Our objective is to provide both watershed planners and state ecologists with the tools and opportunities to make their cases as compelling and supportable as they can,” Katz said.

The scientists assembled by Katz have more than 100 years of collective experience in salmon recovery, habitat management, and the economics of water use. They reviewed decades of research on groundwater ecology, ecosystem characteristics, and the effects and mitigation of groundwater pumping to create the toolkit.

The team included scientists from the Washington Department of Fish and Wildlife, the National Oceanic and Atmospheric Administration’s National Marine Fisheries Service, WSU’s School of Economic Sciences and School of the Environment, and the Water Research Center.

The full team included Katz, Yoder, WDFW scientist Kiza Gates, retired WDFW scientist Hal Beecher, School of Economics Sciences faculty members Mike Brady and Joseph Cook, WRC environmental scientist Julie Padowski, and National Marine Fisheries Service scientists George Pess and Mark Scheuerell.

View the final guidance document on the Department of Ecology’s website. Learn more about streamflow restoration efforts in Washington. View the Water Research Center’s project summary page.