What is recycled water?
Recycled water is highly treated wastewater that has been filtered and disinfected to remove solids and other impurities. Simply put, recycled water is water that is used more than once!
Recycled water is used across the country (i.e. California, Florida, Arizona) and internationally as a sustainable water source to irrigate food crops, but is underutilized and underdeveloped in Washington.
Why use recycled water in agriculture?
With its lush forests and rainfall during the winter months, Western Washington may seem like it has abundant water. However, many local rivers and streams experience low flows in the late summer, when more water is vital for salmon and other fish, because demand and out-of-stream uses are outpacing water availability. Climate change and population growth make this problem worse.
Recycled water may offer a sustainable alternative water source for farms to use in irrigation. Irrigating with recycled water in specific basins can protect flows for wildlife and other instream users.
Tapping into a Sustainable Water Source of Water for Agriculture
In the Sammamish River, if irrigators switched from a river diversion to recycled water for their irrigation source, up to 5 cfs of additional flows could be kept instream during the irrigation season. During the late summer when flows can get down to 20 cfs, this would represent a 25% increase in flows.
The Sammamish Valley Recycled Water Project is working to address concerns about recycled water and to reduce the reliance on the Sammamish River for irrigation. Beginning in 2020, project partners interviewed producers in the Sammamish Valley to understand their baseline knowledge and sentiment towards recycled water as a sustainable irrigation source. Producers were also invited to a recycled water demonstration garden to learn more.
We also gave presentations, tabled at farmers markets, and conducted focus groups and surveys to see how local consumers feel about recycled water. The majority of consumers who participated supported using recycled water to irrigate food crops. That support increased when they learned about associated environmental benefits like flow restoration for fish.
Learn more about recycled water from our project partners:
- King County Department of Natural Resources and Parks (DNRP) – Recycled Water
- King County DNRP – Research Library
- King County DNRP – Sammamish Valley Recycled Water Fact Sheet
- King County DNRP – Sammamish Valley Recycled Water Technical Memorandum
- Washington State Dept. of Ecology – Reclaimed Water Resources
- Washington State Dept. of Ecology – Reclaimed Water Facilities Manual
Thank you Recycled Water Project supporters and partners!
