The High Pressure Water System
AFTER the great fire of 1906 a study was made to determine what further precautions could be taken by the City against the recurrence of such a disaster. As in the days of her earlier history, the citizens determined anew to overcome the fire hazard.
The great fire of 1906 was
caused by the fact that the water mains leading into the City, lying in
A study of the earths fault lines by scientists disclosed that any system of pipes leading up the peninsula would have to cross some of these faults and that at another earthquake the mains might again be broken. With this in mind, the engineers determined that a sufficient amount of water should always be in readiness in the City itself to take care of any fire or fires that might be started as the previous one was.
It was therefore determined to build an entire system of mains independent of the regular water system, for the fighting of fires, and that this system should be supplied from a reservoir, high up over the City, so that no engines would be necessary for pumping. This was to be known as the High Pressure Water System.
It was also determined that this high pressure system should be connected with the bay, so that if by any chance the system should be cut off the reservoir, saltwater could be forced into the system for the purpose of fighting a conflagration.
In addition to these precautions
it was determined to install and extend the system of cisterns throughout
the City so that the Department, if driven to this last recourse, could
always find a sufficient amount of water to find any ordinary fire. In
the great fire of 1906 it was impossible for the Department to get even
enough water to fill the boilers of the engines to generate steam. With
the present motor-
To provide for this independent high pressure system a bond issue of $5,200,000 was voted by the people. By reason of premiums on the bonds sold and interest earned during the building of the system the City realized about $6,000,000.
With this money the City
built a reservoir on the Twin Peaks at the altitude of 758 feet. Water
from this reservoir will go to the top of the highest buildings in the
City through the standpipes that run up the sides of them. This reservoir
has a capacity of about ten and one-
From this reservoir a system of mains leads first to two regulating reservoirs. One, known as the Ashbury tank, is of steel and contains 500,000 gallons of water at an altitude of 465 feet.
The second of these reservoirs
is known as the Jones-
From these three reservoirs
a system of mains radiate throughout the business section of the City.
This district is contained in what is known as the fire limits. As these
limits are extended and the high pressure mains laid, all buildings thereafter
constructed must be of fire-
Taking a lesson from the
Pioneers and their construction of cisterns, fifty-four of the old
cisterns built as far back as 1860 were repaired and placed in service.
In addition to these eighty-
In order to provide for the use of saltwater from the bay, in case the water in the higher reservoirs could not be used, two pumping stations were built on the bay shore. One is known as the Ft. Mason pumping station or pumping station No. 2, and the other is located on the northwest corner of Second and Townsend streets, known as pumping station No. 1. These stations contain electrically driven machinery which at a moments notice can begin pumping saltwater into the high pressure system. If necessary this water can be forced from the bay right up to the Twin Peaks reservoir; or, by closing of valves, the water can be directed through the mains in any desired direction.
One other important unit
was added to the Citys fire fighting system out of this $6,000,000; this
was that of two fire-boats, one known as the Dennis Sullivan and the
other David Scannell. These two boats can pump 10,500 gallons of water
a minute each. They are twin boats and can discharge twenty-
It is believed that with
the precautions the City has so fortified itself that no great fire can
ever again devastate the City.