Project #4736

Adapting to Change: Utility Systems and Declining Flows

Principal Investigator
Research Manager
Ms. Maureen Hodgins
Brown and Caldwell
Climate Change
Utility Management
Water Demand & Forecasting


This project investigated the negative impacts observed by utilities during mandatory municipal water restrictions in California during the drought. Specifically, it looked at drinking water distribution systems, wastewater conveyance, wastewater treatment, and production of reclaimed water. A survey and utility interviews were conducted. The research found that significant reductions in water demand, along with declining flows, resulted in unintended consequences that ripple throughout California's interconnected urban water cycle. Understanding the system-wide impacts of increased conservation will help decision makers address California’s current and future water challenges.

This project produced two deliverables. The 2017 white paper, Adapting to Change: Utility Systems and Declining Flows, provides decision makers, water system managers, and other stakeholders with an understanding of the impacts of declining flows resulting from substantial reductions in indoor water use, and how utilities are adapting to these circumstances. The 2019 issue brief, Adapting to Change: Informing Water Use Efficiency and Adjusting to Declining Flows, builds on the white paper to inform future standards, implications, and adaptions following the 2018 California legislation that set a provisional standard for indoor residential water use of 55 gallons per capita per day.

Co-funding for this project was provided by Association of California Water Agencies, California Association of Sanitation Agencies, California Water Environment Association, and WateReuse California.