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Installing Greywater Irrigation Systems in the Western U.S.

This proposal explains how Greywater Irrigation Systems could be installed across the western United States as a means of reducing water scarcity in our country.

Big Picture: 

The western regions of the U.S. — specifically California, Nevada and Arizona — are facing a water shortage. The insistent threat of climate change only worsens the water crisis in this area. America must find alternative ways to conserve water and maintain responsible water management. 

Operative Definitions:

  1. Greywater: Wastewater from a household or building that has not come into contact with any fecal contaminants. This would include water from washing machines, sinks and showers. 

  2. Irrigation: Supplying water to plants or crops.

  3. Groundwater: Freshwater or drinking water that is found underneath the ground.  

Important Facts and Statistics:

  1. In the western U.S., about 80% of freshwater goes towards irrigation. 

  2. In urban areas such as Los Angeles, it is estimated that lawns contribute to 70% of water loss, according to a study published in Water Resources

  3. Research from the University of Utah. 

  4. The Colorado River and reservoirs like Lake Mead and Lake Powell—all major water suppliers—are falling to record low water levels. Lake Mead is only holding 35% of its total capacity. 

  5. About 65% of fresh groundwater is used for irrigation.  

Five-Point Plan: 

(1) Develop a government-issued guideline on greywater usage. A greywater policy that outlines health regulations and rules regarding the use of greywater should be developed. The policy would cover how to store greywater, how long it is good to use, how to collect it, what its composition can include, the difference between the use of untreated and treated greywater and how to effectively use it. This is to assist when installing or retrofitting greywater systems. 

(2) Educate the public. A critical part of the policy is ensuring that citizens understand the importance of greywater reuse. Strategic advertising and education about the topic would recruit the support of the public.

(3) Mandate greywater systems in all future development. This policy would make it mandatory to include greywater collection and reuse systems in all future developments, from single-family housing to apartment complexes. If the developer wants some sort of landscape, using freshwater would no longer be an option. This policy would be specific to regions in the United States, primarily the West, where water scarcity is a major threat. Although this measure is more drastic, it is a good way to ensure that these systems will be employed and it will help conserve potable water.

(4) Implement a residential greywater system. Accessible and feasible greywater systems will be developed that can be easily installed and maintained within a home. Tax credit for retrofitting a greywater collection system into homes will be offered as an incentive. 

(5) Expand greywater systems to agricultural areas. Greywater systems can be expanded to other areas where feasible, including small farms or agricultural systems. Treated greywater can be used to irrigate food-producing crops as long as it does not come into contact with the part of the plant that is going to be eaten. On-site greywater treatment systems would work best for this kind of operation so that the greywater can be filtered and distributed in the same place. 

Why this Initiative is Important: 

The western region of the U.S. is experiencing intense heat and droughts, throwing the freshwater supply into jeopardy. With the decline in surface water and the consequential decline in groundwater, another supplier of freshwater, western states need alternatives to water management. A residential greywater irrigation system would be a sustainable water management system that would supply nutrient-rich wastewater to landscaping plants and yards, which will filter the water and naturally reintroduce it into the water cycle. This irrigation system would take advantage of the abundant supply of wastewater generated in households, irrigate lawns, help restore groundwater and ultimately conserve freshwater. 


The opinions expressed in this article are those of the individual author, whose information can be found below.

The following student(s) worked on this nonpartisan proposal: Grace Axlund, Miami University.


“LA Lawns Lose Lots of Water: 70B Gallons a Year | UNews.” UNews, 24 May 2017, Accessed 30 June 2022. 

Leonard, Diana. “Reservoirs are Drying up in the Western US.” The Washington Post, 9 July 2021, Accessed 10 June 2022.

Mandler, Ben. “Groundwater Use in the United States.” American Geosciences Institute, 9 March 2017, Accessed 10 June 2022.

“Rebalancing Water Use in the American West.” Environmental Defense Fund, Accessed 10 June 2022.

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

“What is Groundwater.” Groundwater Foundation, Accessed 10 June 2022.

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