The San Francisco call., 1909-11-13
WATER STORAGE TO
MEET EVERY NEED
Fire Protection System Will Be
Capable of Serving 5z,00O,-
600 Gallons in Day

engineering department of the city
government the probability is that
some time within year San Francisco
VIII have an enormous quantity of
water available for extinguishing fires
at high pressure in all parts of the
city. OF all the work designed for the
permanent benefit OF the city. to be
constructed with municipal funds. this
IS of first class Importance In prepara-
tion for the beginning of work on the
Twin peaks reservoirs the assembling
Of the necessary material to serve the
reservoirs is under way Pipe to feed
the city with water as a fire protec-
tfon measure is arriving in San Fran
cisco at the rate Of about is carloads
a day. Nearly 1900 pieces of pipe are
stored IN the city pipe yard and 126
hydrants have arrived.
TOTAL COST is s5,250.0OO
The total investment represented by
the Twin peaks reservoirs and the con-
Meeting part OF the city's FIRE protec-
ton system viii amount to IS $3.50. 600.
The reservoirs on the Twin peaks will
have a capacity OF 5000 600 gallons
each. To construct them will cost
slS5,000, as estimated The time al
iotted for the construction Of the
reservoirs. after the work has begun.
IS $50 days
The reservoirs viii be situated no
feet above the sea level They will be
constructed of reinforced concrete. in
huge holes eXcavated from the rocks.
They viii supply a pressure Of 325
pounds to the square inch. The distrib-
uting system will include "a miles of
pipes, ranging in diameter from 10
- 20 inches. The distributing system
viii cover ali the present populous dis
tricts in San Francisco.
The plans for Nying the pine and
the specifications are nearly completed,
50 that an early beginning will be made
on the work all along the line.
INDERWRITERS PLAN FOLLOWED
The national board Of fire under
writer's, after considering quantities OF
water that have been used at great
fires in the United States and in Eng
land, decided that municipal systems
should be designed so that $4,000 gal
ions Of water per minute might be
concentrated on any area in the con-
gested district of 100000 square feet
The size of mains and the location Of
hy0rants for san Francisco were de-
te' mined upon this basis.
II is estimated that the delivery
OF water viii be sufficient TO cover one
CT the blocks in the so vara survey
more than one foot in depth in one
hour and that the block bounded by
kearny. Post. Grant avenue and SUIT
ter street could be covered to depth
OF IS feet OF water in a day.
AS more than one fire might occur
at a time. or as a part OF the system
might be out Of service. it was con-
Sidered advisable 10 provide for the
delivery into the distributing system
OF more than twice the quantity re-
Quired by the national board OF fire
underwriters or at the rate of $4,000
gallons per minute for 13 hours, and
$4,000 gallons for Ga hours thereafter
PUMPS FOR EMERGENCIES
This is equivalent to 81. 600 900 gal
Ions in the first "A hours, and 10000
900 gallons per day thereafter, and
more than is available from the works
OF the Spring Valley water company,
for all purposes. OF. course. this sup
ply viii not all come from Twin peaks.
The water in excess of that to be
supplied from various reservoirs must
be supplied by the pumping stations.
or which two are TO be esta ablished.
one at the foot Of Van Ness avenue and
one on Rincon hill The pumping sta
ti0ns are TO be used only in an emer-
gency. The supply from the reservoirs
i'll be sufficient for all ordinary fires
as estimated.
Water viii flow from the Twin peaks
reservoirs through two 20 inch mains.
The protected area lies on the easterly
watershed Of the peninsula. between
the POtrero hills and the Golden Gate,
and includes the entire present fire
mits and nearly all the districts in
which shingled roofs are prohibited.
Ia extent it covers $500 acres. equiva-
lent 10 g 2-lO square miles. or nearly
double the burned area.
PROTECTED AREA DIVIDED
- AS the pressure from the storage
reservoirs on Twin peaks will be
s-reater than is necessary. except for
the very largest IRE. and since the
maintenance Of this pressure constant
lv on the mains will involve consider
able expense and some danger. the
protected area has been divided into
two zones.
The lower zone will include an area
of six square miles. taking in those
portions Of the land that are less than
$50 feet high This viii be supplied
from a concrete reservoir having a
capacity Of 100000 gallons, situated
under the roadway OF Jones street be-
tween Sacramento and Clay and haV
ing an elevation of about 329 feet
The roof Of this reservoir will be the
roadway on the street and il will rest
upon concrete and steel beams.
AS this region includes the greater
portion Of the manufa curing and mer-
cantile Industries it viii be surrounded
by "A and IS inch mains, from which
Z and IA inch mains VIII radiate at
Frequent intervals.
The upper zone Will include those
parts Of the protected area that have
an elevation Of more than $50 feet.
This area will include about two and
2 quarter square miles. 1t viii be
supplied from a reservoir containing
s00. coo gallons situated near Seven
feentb and Ashbury streets at an eleva-
ZION of 40 feet
MANSON DESCRIBES PROJECT
city Engineer Marsden Manson, sub
hitting a report on the plan for fire
protection, made the following state
mcnt.
Each of these zones will be sup
rIicd with water under pressure up to
80 pounds from its own distributing
reseIvoir. located at considerably less
elevation than the main storage reser-
voir. When necessary the mains of the
-pper zone may be connected with the
Twin peaks reservoirs and the pressure
raised.
The mains of the lower zone may
be connected with the reservoir Of the
upper zone or with the Twin peaks
reservoirs whenever pressure higher
than ordinary is required. Both zones
are thus commanded by ordinary
pressures for general use and high