The San Francisco call., 1908-10-24
OF WATER
IN HfTCH H[TCHY
Desmond Fitz Gerald and Pro-
lessor Marx Silence All
Objections Raised
Figures Given Show Ample
Source for City in the
Dryest Years

zoe, 900, 900 gallons or water daily TO
San Francisco, or enough for a pepula-
tion of nearly 100000, was attested
yesterday before the public utilities
committee of the board of supervisors
by Desmond F'itzGerald an eminent
Boston engineer and president for two
terms of the American society Of civil
engineers, and Professor C. d. Marx
of Stanford university In the opinion
of DR.. Giannini, chairman of the COM
mittee of the board, the report of the
consulting engineers was particularly
gratifying to the city.
The question propounded to the en-
gineers regarding the capacity of the
watershed to supply the city and the
Turlock and Modesto irrigation districts
was answered definitely in the affirna-
tive by the engineers who worked on
the problem,
we were very much impressed with
Hetch Hetchy and Lake Eleanor" said
Professor Marx. II know of no gather
ing ground in the United States that
affords better and purer water supply
and know of no better dam site any
where in the country" the professor
continued.
PLAN is APPROVED
Desmond FitzGerald spoke most en-
couragingly of the municipalities plan.
~AO oAsASCQ cltOABl1 tHdt dll luC CitlCS
about the bay unite in forming a water
district and secure a supply large and
adequate enough TO supply all the COM
munities. Such a water supply will
advertise the city: it will draw people
to you," he declared.
The report OF the two engineers an
swered in the Affirmative the question
put to them by City Engineer Mars
den Manson regarding the adequacy of
the I.aka Eleanor Jotr "
watersheds. The question was:
Will the proposed development of
Lake Eleanor and Hetch Hetchy reser-
Yoir sites be sufficient to enable San
francisco to secure q water supply of
200,009,000 gallons per day from the
Iuoiumne river, due regard being had
to the granted rights of the Modesto
and Turlock irrigation districts to the
natural flow of the river up to 1850
second feet?v
That ample discussion might be had
on the report of the consulting en-
gineers the public utilities committee
invited citizens generally to attend the
meeting, which was held in the cham
bers of the board.
GAUGE CRITICAL PERIOD
DR.. Giannini presided at the meeting
of the committee, which was attended
by Supervisors Murphy and McLeran,
his associate members, and Johnston,
Payot, Center, Pollok, Bancroft and
others Clerk Behan read the report of
the engineers in answer to the ques-
ton put to them by the city engineer.
In their report Marx and FitzGerald
explained that in order safely to secure
a water supply from any given water
shed 1T was necessary to determine the
yield during the period of longest and
most severe drought. known technically
as the critical period" The average
how of water is an unreliable criterion.
The runoff during the critical periods is
more important than the data on rain
fall Rainfall statistics at La Grange
We're available since 1865 to date and
data on the runoff at that point was
available from United States reports
for the period since 1895
One critical period. from July /, 1897,
TO July /, 1899, occurred during the time
runen data was being taken. That was
for period of sos DAYS.
SAFE SUPPLY IN DROUGHT
Figuring on storage reservoirs of
so,0OO,00O,000 gallons capacity, the re-
port says, concerning that drought:
During the whole Of that time the reservoirs
would have been below their full water line
and there would have been no discharge OF
water into the stream below the dam, exceDt
for the use of the irrigation districts in ac-
cordance with our instructions.
On the basis OF the measured runof at La
Grange. which, as we have already stated, we
believe TO be the most conservative basis that
can be adopted we have computed that during
1875 the safe daily supply for the civ Of
San Francisco from Lake Eleanor and Hetch
Hetehy watersheds would have been at the rate
of 240, 900 gallons daily.
We consider. therefore, that the question you
have asked us is answered in the affirmative
gallons d e Vr snd sboae e
gallons referred 10 in that question.
REVIEW OF RAINFALLS
In reviewing the rainfall records
for the period since 1858 it is learned
that the season 1s76-1S77 had the most
severe drought. Then there was a
showing of rainfall at La Grange of
only 5.74 inches. Concerning this the
report says:
With the natural now OF the stream entirely
diverted to the of the irrigation Districts
which is the worst assumption that be
of drought would have extended from July /,
1878. TO January l. 1873, period OF $40 days.
during which the only dependence of the city
Eleanor and Heteh Hetchy. After allowing for
evaporation and other losses. we find that it
storage to gallons in order to furnish
draft of 2o0. .000, 600 gallons daily.
In conclusion we desire to impress upon your
board the Importance Of beginning as soon as
possible a series OF continuous gangings at the
outlets of the Hetch Hetchy and Lake Eleanor
Wateftueus
Engineer FitzGerald displayed a
chart OF the critical period showing
that the available water. including the
proposed storage of 96,000,600,000 gall
Ions, plus the net yield of 40 $40, 900 900
gallons would be 145.920, 600, 600 for the
drought period OF sos days, which
would give supply of 240,0o0,o00 gall
Ions a day.
EXPENDITURES JUSTIFIED
Then. briefly, he told of the expert
ences of Boston in securing it's water
supply and of subsequent additions
made to the supply. He said that all
the earlier proposals met with fremen-
dous opposition, but that each succeed
ing expenditure for water justified it.
self. The first was for SO 900, 900 for
the original system in 1S49, which had
to be improved by an expenditure of
IS 900 600, and that now Boston and the
surrounding communities have a s40,-
600, 900 system.
James A. Waymire. promoter of the
Lake Tahoe water project, asked Pro-
fessor Marx what the increase of this
city's population would be normally.
and Marx read from an address he made
before the Commonwealth club. in
which he had estimated that the popu-
lation in 1850 would be 100000.
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