SAN FRANCISCO (KGO) -- An upgrade is being made to the emergency fire-fighting system in San Francisco. Over 30 cisterns are being built to prepare for a major earthquake.
Crews have been working very hard over the last few weeks on what San Francisco Fire Department Chief Joanne Hayes-White calls a critical tool to fire fighting.
You may have seen brick circles at intersections around San Francisco and assumed they were just decorations. But they indicate a critical piece of San Francisco's firefighting strategy. They cover a cistern, a storage tank that holds 75,000 gallons of water.
One of 30 new cisterns are being built to compliment 150 already in the system.
"The use of a cistern would be under really emergency conditions, like a big conflagration where we are going need an immediate source of water in the event of a failure," Hayes-White said.
A system of storing water from the Hetch Hetchy Reservoir is thought to be unique to San Francisco and was devised after the 1906 earthquake.
"We've had the experience of the city going up in flames and trying to develop a system that could keep that from happening again," San Francisco Public Utilities Commission Steve Ritchie said.
So far, the cisterns have not been used. During the 1989 Loma Prieta earthquake, fireboats hauled in water from the bay. More recently, the Mission Bay inferno was fought using high pressure water hoses.
However, Hayes-White says the tanks are critical.
"Some people say well you don't really use it on a regular basis, but I can tell you that when the big one hits, these will be invaluable," Hayes-White said.
The 30 news ones are part of a $412 million emergency bond voters passed back in 2010. That includes upgrades to pump stations and pipelines. The outer Sunset will see the first cisterns, with the rest being completed throughout the city by 2017.