Watershed Moment

To better manage drought, the San Francisco Public Utilities Commission is overhauling the Bay Area’s water infrastructure

The Bay Tunnel project, which puts a tunnel in place to bring water to customers on San Francisco’s peninsula, replaces infrastructure originally built in 1925. (Photo: Robin Scheswohl, San Francisco Public Utilities Commission)
The Bay Tunnel stretches five miles and delivers drinking water to the peninsula area of San Francisco. (Photo: Robin Scheswohl, San Francisco Public Utilities Commission)

On April 1, 2015, four years into a drought that has infiltrated nearly every county in California, governor Jerry Brown called for an unprecedented executive order: mandatory water rationing across the state.

“It’s a new world,” Brown announced, standing on a barren peak in the Sierra Nevada where five feet of snowpack should have been. Communities now must take action.

San Francisco, for its part, already has. In the last decade, the San Francisco Public Utilities Commission (SFPUC), the water agency that provides retail and wholesale water service to Alameda, Santa Clara, San Francisco and San Mateo counties, has launched widespread conservation efforts. Rebates on water-saving showerheads and low-flush toilets, as well as partnerships with the city’s Public Housing and Parks and Recreation departments, have plummeted San Francisco’s daily water usage from 53 gallons per person to 45 gallons per person, the agency estimates.

But the commission’s work is far from over. The Sierra snowpack—which releases water throughout California’s dry season—is a key component to the state’s water system. A nonexistent snowpack is troubling for many water agencies in California, but none more than the SFPUC, which relies on the Hetch Hetchy watershed, a reservoir powered by the snowpack, for 85 percent of its water.

(Photo: Robin Scheswohl, San Francisco Public Utilities Commission)
(Photo: Robin Scheswohl, San Francisco Public Utilities Commission)

Hetch Hetchy is different from other water systems for several reasons: it relies on gravity alone to get from its source to the San Francisco Bay Area (and is so pure once it gets there that it doesn’t need to be filtered). Then it flows into Bay Area reservoirs for storage. Those reservoirs are pivotal in times of drought, but aging infrastructure and environmental realities—many sites fall on earthquake fault lines—have put the reservoirs far below the intended capacity.

So while the entire state of California is hunkering down on water usage, San Francisco has a much larger task at hand: updating its water system to better manage drought. In 2002, the SFPUC and its wholesale partners launched the $4.8 billion Water System Improvement Program (WSIP), which comprises 83 projects that, when completed, will revamp infrastructure, increase storage, and diversify sources of the region’s water supply.

At the helm of this incredible effort is Harlan Kelly Jr., general manager of the agency and a veteran engineer. Kelly began his career with the city of San Francisco as a student trainee in the Department of Public Works and worked his way up to become a city engineer in 1996, taking on the responsibility for the development, construction, and design of major buildings and street work. In 2003, Kelly was named assistant general manager of SFPUC, and in 2012, he was appointed general manager.

The Bay Tunnel Project

Crucial parts of San Francisco’s water system cross major earthquake fault lines, particularly the pipelines that deliver water to the peninsula area of San Francisco (“An earthquake could rupture the lifeline to the Bay Area,” Kelly says).

The Bay Tunnel, which was brought into service in 2014 and is nearing completion, transports a water pipe to SFPUC’s peninsula customers under the San Francisco Bay, replacing infrastructure built in 1925 that was far less resilient to earthquakes, according to Kelly.

“Before the tunnel, there were two pipelines that were submerged [on the Bay floor],” he says. “Those pipelines were so old and in sensitive habitat areas. So, we decided to replace them with a tunnel. It’s an amazing system that brings water to the peninsula area of the Bay Area, and it’s a project I’m really proud to be a part of.”

Today, Kelly’s primary focus is bolstering the Bay Area’s water storage to better serve the city during severe drought and other natural disasters. “Storage is really important in a drought; the more you store, the more you have when you need it,” Kelly says. “It’s like a bank account; you can’t just withdraw, withdraw, withdraw.”

The WSIP initiatives, all designed to ensure a reliable water supply, are about 88 percent complete. That last 12 percent, Kelly says, is critical to the future of San Francisco’s water system. “We’re in a state of repair. 2.6 million customers depend on us,” he says.

Calaveras Dam Replacement Project

About 85 percent of the water that the SFPUC provides its customers has to travel the entire width of the state of California to get to the Bay Area. The Calaveras Dam and Reservoir, when full, represents the SFPUC’s largest Bay Area reservoir and half of all Bay Area storage capacity.

Crucial in previous drought years, the reservoir is currently low because its dam is outdated and unsafe, Kelly says. So, his team is building a new dam downstream of the existing one to restore the reservoir to its previous capacity—nearly 31 billion gallons of water. The restoration, which is the largest and most complicated project of the overhaul, is slated to wrap up in 2018.

“An earthquake could compromise Calaveras, so we’re maintaining a lower level than a normal operating dam,” he says. “[The restructure] allows us to make it stronger, increase capacity, and turn the reservoir back to its historical capacity.”

The Lower Crystal Springs Dam, which sits about 30 miles from Calaveras on the opposite side of the Bay, recently underwent a seismic retrofit. That dam, which was built in 1888, is now back to its original height of 22 billion gallons of storage, according to the SFPUC.

The Calveras Dam and Reservoir, when full, represents half of all Bay Area storage capacity. (Photo: Robin Scheswohl, San Francisco Public Utilities Commission)
The Calveras Dam and Reservoir, when full, represents half of all Bay Area storage capacity. (Photo: Robin Scheswohl, San Francisco Public Utilities Commission)

Regional Groundwater Storage and Recovery Project

A collaborative project with other Peninsula cities, the Regional Groundwater and Recovery Project allows the SFPUC and its wholesale customers to reduce groundwater pumping so there is more free water in dry years—about 20 billion gallons more, according to the SFPUC.

Previously, neighboring water agencies would get a portion of their water from the SFPUC and a portion from groundwater, even during “wet years,” which unnecessarily depletes a vital storage resource, Kelly says. Through the new program—which just started construction and calls for the drilling of 13 new wells on the San Francisco Peninsula—the SFPUC will share its Hetch Hetchy water supplies with three other water agencies during wet and normal years as a means of conserving and storing groundwater for use in a future drought.

“It’s just another form of storage, and it’s a great program,” Kelly says.