A fire that destroyed a Treasure Island building Wednesday night tested the limits of the island’s water supply as developers and planners put the finishing touches on a massive redevelopment plan that would increase the island’s population and stretch existing infrastructure.
The fire that raged through a closed Navy barracks reached three alarms shortly after it was reported at 11 p.m., San Francisco fire Lt. Mindy Talmadge said. Firefighters deployed a pumping boat for the first time since the 1989 Loma Prieta earthquake, but did not use it.
The isolated, abandoned structure was allowed to burn itself out, but Talmadge said the department would have needed to pump Bay water onto the blaze through high-volume hoses if it had posed a threat to safety or to other structures. The existing water storage and distribution system on Treasure Island would not have been sufficient to put out the fire Wednesday had it been threatening safety or other structures, Talmadge said. With a massive development including high-rises and 6,000 residential units planned for the island, fire officials contend the water pressure will not meet fire safety standards without a high-pressure backup system.
Treasure Island receives its water through a 10-inch pipe run along the western span of the Bay Bridge, with a secondary supply option through a pipe on the eastern span. Under the latest version of the new plan for redevelopment of the former Navy base, the water supply would remain the same.
In mainland San Francisco, the fire department owns and maintains a secondary, high-pressure system of nonpotable water in addition to The City’s main water supply. Talmadge said the department is pushing for a similar system to be included in the development plans for Treasure Island.
“The [department’s] stand right now is that we need the extra pressure, especially if there’s going to be a population on that island of any significant amount. Last night was a good example of that,” Talmadge said.
The latest version of the development plan promises to “explore the use of a limited Bay water AWSS (alternative water supply) system,” which would include “suction hydrants” and “Bay water manifolds” located around the perimeter of the island. The plan indicates that the development partners, which includes the Lennar Corp., intend to discuss the system further with the fire department.
On Thursday, San Francisco Public Utilities Commission Spokesman Tony Winnicker said the existing tanks, which hold about 3 million gallons of water, provided enough pressure to feed the hoses that were hooked up to them. But he said the system will need to be upgraded before it can serve the expected development slated for the island.