California's water-conservation challenge could be nearly solved if the pipes, water mains and aqueducts that carry the state's drinking water didn't leak.
But even if every pipe was secure and enough rain came this winter -- a reprieve that's looking less and less likely -- the state's current reduced water use is going to be "the new normal," state water officials said Tuesday, drought or no drought.
As much as 10 percent of water used by urban areas is lost thanks to leaking transmission pipes, according to the State Water Resources Control Board.
If state water agencies did a better job at detecting and repairing leaks, as much as 350,000 acre-feet -- or 114 billion gallons -- of water could be saved every year, the State Water Resources Control Board estimates.
Conservation efforts to date, including letting lawns brown and cutting back on washing cars, has saved 480,000 acre-feet of water so far in 2014, according to Max Gomberg, a climate change advisor with the agency.
The state uses about 43 million acre-feet of water per year. One acre-foot of water is 326,000 gallons.
California's 38 million people use about 21 percent of the state's water, according to state officials. The rest is consumed by the state's giant agriculture industry.
The San Francisco Public Utilities Commission, which manages the drinking-water supply for 2.6 million Bay Area homes and businesses -- including all of San Francisco, and much of San Jose and the Peninsula -- loses about 5 to 6 percent of water delivered in The City to leaks, agency spokesman Tyrone Jue said.
That's as much as 3 million gallons a day.
Of the total water delivered from the Hetch Hetchy Reservoir in Yosemite National Park, about 4 percent goes into the ground from leaky pipes, Jue said.
That's a significant amount of water, but that loss is well within the accepted industry standard, Jue said.
"We have a lot of leaky pipes because our system is over 100 years old," SFPUC General Manager Harlan Kelly told Gov. Jerry Brown's Drought Task Force on Monday.
The state is in the third year of one of the driest spells in its history. Brown declared a drought emergency in January. All 58 California counties are affected, and most of the state is in the most severe possible state of drought, according to the U.S. Drought Monitor.
To stave off environmental and agricultural disaster, Brown has asked water users to cut back at the tap by 20 percent. Mayor Ed Lee asked San Francisco water users to reduce consumption 10 percent.
These measures, while imposed because of the drought, may last well past when the rains finally come, Mark Ghilarducci, director of the state's Office of Emergency Services, said Monday at the SFPUC's headquarters.
"The drought is a crisis situation ... but in many ways, it's going to become the new norm in California," he said, noting that as the state's population grows, water demand will grow, too. "We need to think about how we're sustaining this very critical resource."
Plugging the leaks
- 350,000 acre-feet of water could be saved if moderate measures were taken to plug leaks
- 480,000 acre-feet saved in California thus far during drought conservation efforts
- 43 million acre-feet used in California annually
- 34 million acre-feet is annual agricultural use
- 8.7 million acre-feet is annual urban water supply
- 10%: Amount of water used in urban areas that is lost due to leaking pipes
- 870,000 acre-feet lost to leaks
One acre-foot is equal to 326,000 gallons of water
Source: State Water Resources Control Board
Correction: This story was updated Aug. 12 to correct the percentage by which Mayor Ed Lee had asked San Francisco water users to reduce consumption. The correct figure is 10 percent.