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Greywater Can Aid the Water Crisis in the Western U.S.
ONC Editorial

Mar 17, 2023

Greywater irrigation systems should be installed to help conserve freshwater in the western United States and to promote sustainable water management within urban settings. (The opinions expressed in this piece are those of the individual author, whose information can be found below.)

The western U.S., primarily California, Nevada and Arizona, is facing an extreme water shortage. Major water suppliers, such as the Colorado River and Lake Mead, have reached record low water levels, accentuated by the strong and persistent presence of climate change. The ‘bathtub ring’ is a visual marker of the stark difference between water levels in these reservoirs, displaying the amount of water that has been lost. Heat intensity and droughts also contribute to the depletion of groundwater, another major source of freshwater for these states. The decline in groundwater is especially concerning as the recharge time of aquifers is a slow and lengthy process. Greywater, or household wastewater that has not come into contact with any fecal contaminants, is a sustainable alternative for water management. Given its abundance and easy access, the western U.S. should use greywater to assist and mitigate water scarcity in the region. 

Greywater can be used in diverse ways. Not only can greywater be used for various water applications in and around a household, thereby reducing fresh and potable water consumption, but greywater will also decrease runoff into bodies of water where it is a pollutant to marine life and ecology. 

Irrigation uses a considerable amount of freshwater and is crucial for growing crops and providing food to a large population across America. Approximately 70% of freshwater is used for agricultural purposes. In places like the western U.S. where there is an insufficient amount of freshwater, greywater can help with irrigation. With proper treatments, greywater collected from industrial buildings and households can be used to supply water to landscaping and food-producing plants on a larger scale. Utilizing greywater in this capacity will spare freshwater from use while providing nutrient-rich wastewater to soil and plants, which will then be filtered and eventually introduced back into the water cycle. It will also aid in restoring groundwater and can be used during extended periods of drought. 

Taking the many benefits into account, installing complex greywater irrigation systems will help conserve freshwater in the western U.S. and promote sustainable water management within an urban setting.

Grace Axlund is an undergraduate student at Miami University where she is working towards her bachelors degree. She is majoring in Urban and Regional Planning, co-majoring in Sustainability, and minoring in Photography. She is an Infrastructure intern at ONC and has been with the organization since May 2022.


“Drought and Groundwater Levels | US Geological Survey.” USGS, Accessed 4 June 2022. 

Hand, Eric. “Western U.S. States Using up Ground Water at an Alarming Rate.” Science, 24 July 2014,

Sahawneh, Eyad. “Importance of Reuse of Greywater.” EcoMENA, 8 July 2020, Accessed 4 June 2022.

Water Science School. “Irrigation Water Use.” USGS, 7 June 2018,

“Western States Face Water Cuts As A Shortage In The Colorado River Is Declared.” NPR, 16 August 2021, Accessed 4 June 2022.

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