Scattered round San Francisco are a complete of 177 massive cisterns buried beneath the streets. Their presence is seen at many intersections within the form of enormous brick circles embedded within the pavement. These cisterns maintain town’s emergency water provide, for use ought to town’s home water provide fail within the occasion of a nasty fireplace.
San Francisco is the one metropolis on the planet to have such a system. The cisterns type an integral a part of town’s Auxiliary Water Provide System that consist—other than the cisterns—water reservoirs, pump stations, suction connections and fireboats, and was designed to assist firefighters take care of emergencies.
A circle of bricks marking the place of a subterranean cistern. Picture: christeli_sf/Flickr
The AWSS was conceived and deliberate in response to the failure of the prevailing water system through the devastating fires that ravaged San Francisco following the notorious 1906 earthquake. Inside three days of the earthquake, fires destroyed roughly 25,000 buildings on 490 metropolis blocks. Many fires have been brought on by ruptured gasoline mains, however many others have been intentionally began by house owners of destroyed properties in order that they might declare insurance coverage on their properties, as a result of their insurance coverage insurance policies lined harm from fires however not from earthquake. Fireplace grew to become the one most harmful drive within the metropolis, with some estimates placing the loss as a consequence of fires as excessive as 90 % of the overall destruction.
San Francisco’s early settlers have been no stranger to fires. A metropolis that rose out of the gold rush was a veritable tinderbox with rickety picket homes, tents, the hulks of ships, and something that afforded safety. Throughout the first two or three years of its historical past, there have been six main fires, the primary in January 1949 when the Shades Resort burned to the bottom. Just a few months later, a ship went up in flames because it was getting ready to sail. In the direction of the top of the identical 12 months, one other fireplace started in the midst of the japanese aspect of the Plaza, that consumed practically all that aspect of the sq.. This was the primary nice fireplace which devastated San Francisco.
Fireplace in San Francisco Bay, 1856. Oil on canvas, by Charles Christian Nahl and Hugo Wilhelm Nahl
Six months in a while Might 4, 1850, a hearth ravaged three blocks of essentially the most beneficial buildings within the metropolis. Following the hearth, a 12,000-gallon cistern, one in all many to comply with, was constructed in Portsmouth Sq.. Artesian wells have been additionally dug in varied components of town and an ordinance was handed ordering all house-holders to have six water buckets stored in readiness for fires. However these preventive measures weren’t taken in time. A month later, a 3rd fireplace broke out from a faulty chimney in a bakery and the ensuing fires consumed all of the blocks between Clay, California and Kearny streets to the water.
Fires grew to become a repeated prevalence within the metropolis, breaking out each two to a few months. On Might 4, 1851, precisely a 12 months after the second nice fireplace, a catastrophic conflagration destroyed as a lot as three-quarters of San Francisco. It was essentially the most devastation fireplace to this point. Hardly six months handed when one more fireplace began, utterly gutting ten blocks and partially destroying one other six. Cautious of frequent disasters, individuals started to construct homes with strong bricks, some two to a few toes thick, to make them fireproof. However these superior constructions have been confined to the central enterprise part, whereas on the fringes and within the residential sections, the buildings continued to be of wooden body building.
San Francisco Mission District burning within the aftermath of the San Francisco Earthquake of 1906. Picture: Chadwick, H. D/Wikimedia Commons
In response to the fires, town put in a contemporary water provide system with over 4 thousand hydrants, that quickly changed the outdated time fireplace cisterns. Then the bottom shook on April 18, 1906, and town’s water pipes sprouted leaks in all places. Consequently, the hearth division misplaced water stress on the identical time that busted gasoline strains sparked a conflagration. Finally, it was water from these cisterns that helped firefighters save many neighborhoods from full destruction.
Having discovered their worth, town ordered the creation of over 150 new cisterns as a part of the Auxiliary Water Provide System, which additionally included a community of pipelines constructed solely for firefighting that was utterly separated from the common water provide pipelines. The strategically situated cisterns have capacities starting from 75,000 to over 200,000 gallons every, and collectively they’re able to retailer roughly 11 million gallons of water citywide. These cisterns are standalone reservoirs and are usually not related to the system’s water provide. Their presence is indicated by a circle of bricks with two manholes, the covers of that are embossed with CISTERN and S.F.F.D (San Francisco Fireplace Division).
For the reason that 1906 earthquake greater than a century in the past, the cisterns haven’t been used. However they’re nonetheless down there and repeatedly maintained prepared to avoid wasting town when the subsequent calamity strikes.
Map of San Francisco’s cisterns by Scott Kildall
Water cistern in San Francisco, California, within the Potrero Hill neighborhood, on the intersection of Mariposa and Missouri Streets. Picture: Mark Hogan/Wikimedia Commons
Inside a cistern within the Mission District, San Francisco, California. Picture: Robin Scheswohl/Wikimedia Commons
A manhole cowl over a cistern in San Francisco. Picture: Nick Sherman/Flickr
# Early Historical past of the San Francisco Fireplace Division, www.sfmuseum.net
# San Francisco Fire Department historical review, 1849-1967
# Thomas Ok. Pendergast, Auxiliary Water Provide System Enlargement Deserted, FoundSF