Roofwater Harvesting In California: Obstacles and Opportunities

The WATER Institute released this roofwater report in June 2011 that supports statewide adoption of this valuable water conservation strategy to increase community water security and stream flows for salmonid recovery. This report was a result of a meeting in 2010 and offers a broad overview of the status of roofwater harvesting in California, investigates obstacles, proposes solutions, offers recommendations for next steps and provides resources for further research.

Table of Contents

Executive Summary
Cultural Analysis
Regulatory Analysis
Technical Analysis
Scientific Analysis
Economic Analysis
Appendix 1
Appendix 2


Brock Dolman and Kate Lundquist of the Occidental Arts and Ecology Center’s WATER Institute produced this document, together with Kevin Swift of Swift Writing. Kyla D. Schwaberow provided layout and design. Wesley Look created the list of California agencies that exert power over water. All photos by Brock Dolman, unless otherwise noted.

Much of the information in this document originated at a meeting held in November 2010 at the Occidental Arts and Ecology Center (OAEC). Thanks to Dave Henson, Executive Director of OAEC, for facilitating this day long meeting and to the staff of OAEC for hosting and providing a delicious organic lunch. We would like to thank the following participants who contributed their valuable time and input at this meeting:

Brian Cluer — National Oceanic and Atmospheric Administration Fred Euphrat — Forest, Soil & Water, Inc.
Eric Berntsen — CA StateWater Board
Steven Chatham — Prunuske Chatham, Inc.

Lauren Hammack — Prunuske Chatham, Inc.
Mary Ann King — Trout Unlimited
Brad Daniels — Trout Unlimited
Carrie Sendak — Salmon Protection and Watershed Network Jeff Adams — Salmon Protection and Watershed Network

Thanks to the Gold Ridge RCD and Matthew Deitch of the Center for Ecosystem Management and Restoration, for use of his GreenValley Creek Hydrograph (GreenValley CreekWatershedAssessment,Gold Ridge RCD 2010), and the City of Santa Rosa Utilities Department for the use of their ETo graph.

Thanks also to the following organizations and web sites from which many of our resources were derived: www.,,,

Cover photo: Residential roofwater system installed by the Gold Ridge RCD’s Save Our Salmon (SOS) program in Bodega, CA

This report was made possible with support from the National Oceanic and Atmospheric Administration.

Rooftwater Harvesting California