A new study out of the Pacific Institute in Oakland finds that California can save more than a million acre-feet of water each year — or 890 million gallons a day — through conservation and improved water efficiency. That’s close to 12 times the annual water usage of the city of San Francisco, and it’s roughly equal to the water required to grow all the grain produced in California.
The report’s lead author, Heather Cooley, says the strategies outlined in this report can help the state achieve its goal of a 20% reduction of per capita urban water use by 2020.
The Final California 20×2020 Water Conservation Plan [PDF], which was released in February, lays out a plan to reduce urban water use from 192 gallons per capita per day to 154 gallons by 2020. According to the plan, this represents an annual savings of 1.59 million acre-feet.
“California’s water problems require a portfolio of solutions. That’s certainly true,” said Cooley. “But we can’t do everything at once. We must do the most effective things first, and certainly water conservation and efficiency falls into that category.”
The state’s reservoirs are actually doing pretty well right now, thanks to a wet winter, but no one thinks that the state’s water woes are over. Population is expected to increase, especially in the driest regions — the Central Valley and the South. And scientists predict that the state is going to grow hotter and drier as the years go on. Plans are in the works for increasing water supply and improving the state’s water infrastructure, but many of those are on hold. The $11 billion water bond originally slated for the ballot this fall was bumped to 2012, so a major water overhaul is not on the near horizon.
Cooley says that many proposed projects are more expensive and yield less water than conservation. She cited the proposed dam at Temperance Flat on the San Joaquin River, which would provide far less water (approximately 158,00 acre-feet) and would cost more (the Bureau of Reclamation estimates $3.4 billion) and would have environmental consequences.
Conservation, she argues has no negative environmental consequences, and it actually saves energy. But it’s not free. Saving 890 million gallons of water a day through increased efficiencies would cost the state approximately $1.9 billion, Cooley estimates.
“There is an upfront investment, but in the long term, these efficiency improvements are far cheaper than many new supply options,” she said.
The plan targets both urban and agricultural use. In cities, the report recommends changes such as replacing inefficient toilets, washing machines and other appliances, and swapping out lawns for landscaping with low-water-use plants. In the agricultural sector, which currently uses 80% of the state’s developed water supply, the report recommends implementing more efficient irrigation technologies and strategies.