California, perhaps more than any other of the United States, has been a leader in water efficiency experiments. It adopted uniform efficient plumbing standards in 1978 for showerheads and faucets and the same for water closets in 1992. Comprehensive water management planning was adopted in 1983 for all water agencies serving more than 3,000 connections or 3,000 people, and in 1991, a Memorandum of Understanding was signed by major water utilities and environmental groups statewide - pledging to implement standardized water efficiency programs called “Best Management Practices” in an attempt to help save the dying Bay-Delta Estuary. The California Urban Water Conservation Council, created by this Memorandum, is a non-profit NGO formed to oversee the Best Management Practices and to enforce the terms of the Memorandum. Since the historic signing of this Memorandum ten years ago, the Council has become a national example of consensus partnership on water efficiency. Water utilities and environmental groups work together on defining programs for water conservation, not as adversaries fighting each other in the press or in the courtroom. Technical assistance provided by Council staff helps utilities plan and implement conservation projects. This paper will outline national programs and will focus specifically on the Council partnership, which has resulted in benefits to water utilities, environmental groups, and state governmental agencies alike.