California voters won't get a chance on Nov. 6 to help decide the fate of Hetch Hetchy, a magnificent canyon in Yosemite National Park that has been submerged by part of San Francisco's water supply for nearly 80 years.

But voters statewide – especially those who care about our national parks – should watch carefully to see what San Francisco decides on Proposition F, a city ballot measure.

That farsighted proposition would require the city to study alternatives for the water and power provided by Hetch Hetchy. Since San Franciscans tend to be more environmentally sensitive than their leaders – and much more eager to explore the possibilities – there's a good chance they will vote in support of Proposition F.

Contrary to the rhetoric of reservoir defenders, Hetch Hetchy is not San Francisco's primary source of water, and draining it would not be disastrous. There are nine reservoirs that supply water to San Francisco, and Hetch Hetchy stores less than 25 percent of the total.

As UC Davis engineering professor Jay Lund wrote last month in the San Francisco Chronicle, "The Bay Area does not need the Hetch Hetchy reservoir to continue Tuolumne River water deliveries. Modifying the Hetchy Hetchy aqueduct to take water from Cherry reservoir or from the larger Don Pedro reservoir downstream could supply full Bay Area deliveries almost every year, with occasional shortages supplied from groundwater, reuse, conservation and water purchases."

If Proposition F were to pass, it would not automatically result in the draining of Hetch Hetchy. It would, however, force normally progressive San Francisco to study 21st-century ideas for efficiently using water. This includes expanded use of groundwater management and water recycling.

Although San Francisco officials say they are "working" on these alternatives, they have yet to follow the lead of many coastal water districts that recycle significant quantities of water. The Orange County Water District, for instance, recycles 92 million gallons of water daily.

If San Francisco were to get serious about a modern water management plan, it might help restoration proponents build their case that draining Hetch Hetchy would be feasible. But even then, San Franciscans would get a chance to weigh in, possibly through a vote in 2016.

Submerging Hetch Hetchy might have made sense during the early 20th century, when San Francisco was recovering from an earthquake and natural parks had little value to most Americans. Now all of that has changed.

Cities no longer need to depend on high-mountain reservoirs to avoid waterborne diseases. Modern treatment technology can take care of that.

Yes, that would cost money, but in considering the possible price tag, Californians also need to consider the costs of the status quo. Roughly 4 million people visit Yosemite yearly, but few visit Hetch Hetchy, partly because the canyon is under water and the reservoir itself is off-limits to boaters and swimmers.

This should be unacceptable in a national park. It is a mockery of what these parks are supposed to be about.

San Francisco voters can take a step toward changing that by voting "yes" on Proposition F.

© Copyright The Sacramento Bee. All rights reserved.

• Read more articles by the Editorial Board

Order Reprint