Water Plan Has Some Leaks
By Tom Doudiet
In response to the February article (Richmond Review/Sunset Beacon) on the use of both Lake Merced water and Sunset Reservoir water to fight post-earthquake fires in the Outer Richmond and Outer Sunset, it is gratifying to see that the SF Public Utilities Commission (SFPUC) is finally willing to concede that the use of our drinking water alone will not enable the SF Fire Department (SFFD) to combat post-earthquake fires in hundreds of blocks of wood-frame housing.
That it has now now included the more than two billion gallons of non-potable water in Lake Merced as a source of emergency water supply for the proposed high-pressure hydrant system in these two neighborhoods is a significant step in the right direction, but its overall proposal is still far short of the comprehensive plan needed to mitigate post-earthquake firestorms citywide.
First, there are 15 western and southern neighborhoods that lack the protection of high-pressure, high volume Auxiliary Water Supply System (AWSS) hydrants, so a piecemeal plan for only two of these neighborhoods will not prevent widespread destruction by post-earthquake fires.
We were given a glimpse into the intensity of the fires that will result from dozens of gas line ruptures that a major earthquake will produce by the recent explosion at the intersection of Parker Avenueand Geary Boulevard. The lesson that we must learn is that, while a single such incident can be managed (barely) by the SFFD using conventional water supplies from low-pressure hydrants, the time required by PG&E to shut off the gas (about three hours) resulted in the continuous need for large quantities of water over an extended period, as the wood-frame buildings surrounding the rupture had to be protected from the radiated heat of the gas-fueled fireball. Post-earthquake, the SFFD will be unable to fight multiple gas-fueled fires in neighborhoods that have no AWSS hydrants, and thus whole neighborhoods will be destroyed by firestorms.
Second, while the addition of Lake Merced water into the proposed Richmond/Sunset plan greatly increases the potential volume of water, the SFPUC has thus far not explained how this non-potable water will affect the drinking water mains that will come out of Sunset Reservoir and be part of this same firefighting system. Given that up to two thirds of the water in the City’s terminal reservoirs will, under State Water Code Section 73503, have to be shared with 27 cities on the Peninsula following a regional disaster, the water available from Lake Merced will make the relatively tiny amount of water from Sunset Reservoir almost meaningless for post-earthquake firefighting: two billion gallons (Lake Merced) is 67 times the amount of water (30 million gallons) that might be available from Sunset Reservoir (after two thirds of the water goes to the Peninsula). This again begs the question of why we would choose to use our drinking water, which will be in critically short supply for a very long time following a major earthquake, to fight fires.
Third, Lake Merced is not the only non-potable source of water that can be used for post-earthquake firefighting – the inexhaustible water supply that we have readily available on three sides of the City (namely, the Pacific Ocean), literally adjacent to the 15 unprotected neighborhoods, for over a hundred years has been the primary water supply for the AWSS hydrants (currently about 1,600 in number) that exist in other neighborhoods. In addition to the high pressure pump station at Lake Merced, the installation of saltwater pump stations at Ocean Beach and Hunters Point would give the SFFD an adequate water supply to combat post-earthquake fires in every San Francisco neighborhood and thereby save our wood-frame housing stock from total destruction by firestorms. Recall the photos of the Santa Rosa neighborhoods or the town of Paradise after the firestorms overcame their limited source — low-pressure hydrant systems. Only brick chimneys and foundations remained.
So, inasmuch as the water available from Sunset Reservoir would be insignificant in comparison to the non-potable water that is readily available to the City for post-earthquake firefighting, why is the SFPUC so adamant about using drinking water as part of a high-pressure firefighting system? Perhaps because it is seen as an opportunity to (mis)appropriate Earthquake Bond money to fund the building of reinforced drinking water mains, which, by law, should be paid for by water revenues, not by general fund bond money. The fact that the amount of drinking water from Sunset Reservoir that could ostensibly be used for post-earthquake firefighting would be virtually meaningless, when compared to the water available from the non-potable sources of Lake Merced and the Pacific Ocean, should finally put to rest this absurd premise of using our drinking water to fight post-earthquake fires.
Fourth, what is actually required, if the SFFD is going to have a reality-based plan to control post-earthquake firestorms, is a comprehensive expansion of the existing AWSS pipelines and hydrants into all 15 of the currently unprotected neighborhoods, a plan that has been repeatedly proposed and repeatedly shelved over the last fifty years, a plan that will use the inexhaustible non-potable sources of water that are readily available to “The City That Knows How.”
The current piecemeal approach using our drinking water, which the SFPUC has tenaciously promoted since abandoning the comprehensive AWSS expansion plans that were published in 2009 (in an independent study, by the engineering firm Metcalf & Eddy, that the SFPUC commissioned), will simply not provide the volume of water nor the pressure that the SFFD will need in all neighborhoods following the next major earthquake. The piecemeal approach is based on magical thinking.
It is time for the mayor to take charge of this situation and establish the comprehensive expansion of the AWSS into all San Francisco neighborhoods as a critical priority for the survival of the City. As a result of the recent Richmond District gas line rupture, it should be obvious that this is a matter equal in importance to the rebuilding of the seawall, which can be accomplished for about 20 percent of the cost. The alternative is for City Hall to concede that in order to avoid spending the one billion dollars to build the AWSS project, it is willing to sacrifice thousands of lives and tens of billions of dollars worth of wood-frame homes and businesses, in the unprotected neighborhoods, to post-earthquake firestorms.
Thomas W. Doudiet is a retired assistant deputy chief with the SF Fire Department.