It is misguided, as this article from the California Water Alliance makes clear.
No one questions the need for Californians to avoid wasting water and conserving our precious water resources. Water we need for our people, cities, environment, wildlife, fish and food producers is wasted primarily because California lacks the necessary storage facilities to capture and hold the water during the summer and drought years.
California’s Mediterranean Climate means that most of its precipitation — rain and snow — falls during a few short months of winter and spring, from October to May. The rest of the year is dry. Much of that water — with the most flowing in wet years like 2017 — just dumps into the Pacific Ocean to be lost forever.
While California’s population is now at 39 million, its dams and other water storage systems were built 40-60 years ago to serve less than 25 million people. The introduction of a new water user began in the late 1980s and grew in less than 25 years to consume over half of all the developed water we capture and store in California.
While our cities, businesses and people use 10 percent of all developed water used, and 40 percent is used for food production, the new water user created through state and federal environmental regulations and by court decisions now accounts for 50 percent.
When water supplies are insufficient and we experience drought, underground water reservoirs are drawn down, causing land subsidence and increasing the cost and depth of water supply wells. Wet years allow those aquifers to refill, so providing surface water deliveries to avoid more pumping is essential to good management of the state’s underground water resources.
Water conservation by Californians also helps extend our existing water supply, but it cannot make up for strategic shortfalls due to insufficient storage infrastructure. The total water consumers save — even when it’s 25 percent or more of their use — makes up a very tiny portion of the total water used throughout the state. The conserved amount is also dwarfed by all the water that California does not capture and store, water that flows unchecked to the sea at all times of the year, but especially during our wet season. In all, during the peak drought years of 2015–2017, conservation measures extended the water supply about five percent compared to the amount of fresh drinking water the state allowed to flow into the ocean.
California must do a better job of managing its water for people, business, industry, farmers and the environment. A 20th Century water supply system cannot meet our 21st Century needs.