A simple sensor is helping communities stop wasting water they can’t afford to lose – and proving that small solutions can have an outsized impact.
14+ million gallons
saved per year across our project portfolio
~20%
reduction in water use at participating properties
16 properties
in California and Arizona
97% of residents
surveyed say they feel a responsibility to help save water
THE PROBLEM
Water too valuable to waste – quietly going down the drain
Every year, household leaks waste nearly 1 trillion gallons of water nationwide — and toilets are one of the biggest offenders. In large multifamily buildings, a single running toilet can silently waste hundreds of gallons per day. But finding that leak is nearly impossible: most large properties have just one water meter for the whole building, so finding a leak is like searching for a needle in a haystack.
In the drought-strained American West, this is water we simply cannot afford to flush away.
“Even the smallest leak can make a major impact… Resident and maintenance staff may not know there is an issue until a significant amount of water has already been lost. That’s why this technology matters.”
Mayor Kate Gallego, City of Phoenix
OUR APPROACH
Small actions adding up to big impact
Since 2021, the Pacific Institute has helped deploy an innovative toilet leak detection system across 16 affordable multifamily properties in California and Arizona. The solution is elegantly simple: a small sensor attaches to the supply line of each toilet and connects to an online platform that instantly alerts property managers when a leak is detected — so repairs happen in hours, not months.
SOCIAL IMPACT
Conservation for communities that need it most
Water efficiency solutions too often bypass the communities facing the greatest need. This initiative changes that by bringing cutting-edge technology to affordable housing, reducing costs for property managers, and letting low-income residents participate in conservation without added burden.
In a survey of 100 residents at participating properties, over 90% said they are concerned about water scarcity and feel a responsibility to help save water. 85% said knowing their building is taking action makes them happy to live there.
“Millions of gallons of water run through our properties, so it’s important to us that we do our part to preserve and sustain wherever we can.”
Tina Booth, Director of Asset Management, Housing Authority of the City of Los Angeles
PARTNERSHIPS
Unlikely alliances, outsized results
What makes this initiative successful is the coalition behind it. This project brings together people who don’t typically share a table: environmental researchers, affordable housing operators, water utilities, a tech startup, and Fortune 100 corporations.
In Phoenix, the mayor’s office, City Water, and City Housing united around a single toilet sensor. In Los Angeles, local and regional utilities offered rebates. Corporate partners provided funding through their water stewardship commitments. The Pacific Institute convened it all, in partnership with Sensor Industries and the Bonneville Environmental Foundation.
The result is a replicable model for cross-sector collaboration that can scale to cities across the United States and beyond.
“This project has a low entry point to investment and you’re able to see the benefits so quickly and you can measure the savings. Not only the volume savings, but also the dollar savings, and even getting towards energy benefits and other benefits.”
Shannon Quinn, Procter & Gamble
RECOGNITION
Awards
This work has been recognized for its innovation and real-world impact.
As drought and climate pressures intensify across the western United States, the opportunity is clear.
And it starts with fixing what’s hiding in plain sight. Learn how you can get involved in the initiative or support the work.
RESOURCES
- Saving Water and Money Through Toilet Leak Detection: A Los Angeles Case Study in Affordable Multifamily Housing (2024, Pacific Institute)
- Saving Water in Affordable Housing One Leaky Toilet at a Time (2024, Pacific Institute)
- Saving Water, Time, and Money by Fixing Leaks in Affordable Housing (2023, Pacific Institute)
- Fillmore Gardens Project Launch Press Conference with Phoenix Mayor (2026, City of Phoenix)
- Metropolitan celebrates four inspiring water-saving projects at One Water Awards (2025, Metropolitan Water District of Southern California)
- Metropolitan Water District of Southern California One Water Awards: The Housing Authority of the City of Los Angeles (2025, Metropolitan Water District of Southern California)
- Leak Detection Pilot Program Kickoff (2023, Phoenix Installation Press Conference with Mayor Gallego)
- Toilet Sensors Help Renters Reduce Water Waste from Leaks (2023, Spectrum News 1)
- Saving water in L.A., one leaky toilet at a time (2022, Google)
- Bonneville Environmental Foundation
- Cascade
- City of Phoenix
- The Coca-Cola Company
- Cummins
- Disney
- Ecolab
- Hunter
- Los Angeles Better Buildings Challenge
- Los Angeles Department of Water and Power
- Metropolitan Water District of Southern California
- P&G
- Primo Brands
- San Francisco Public Utilities Commission
- Sensor Industries
- Target