Daily Los Angeles herald., 1878-01-22
yos guseles Aerald.
PROFESSOR Davidson on Irr.E.s,ou.


last Wednesday evening. He used |
a blackboard freely to illustrate.
The main points made We present: |
The rights Of land and water he
first considered. Where irrigation |
is a necessity, all irrigable lands
should have equal rights to the
water available for that purpose.
The water should go with the land,
and the land must carry the water.
In Italy and Spain the water is
sold by measurement, and like
system to that in use in the Cali
fornia mines he would apply to the
water of irrigation. AS to the
quantity of water necessary to raise
Is crop, authorities differ. Exhibits
are made to show the actual duty
OF water, but all results fall short
Of the theoretical duty. The best
authorities allow from 10 to II
inches of water to produce crop Of
wheat, barley and maize, applied
In four waterings, or in three
waterings of four inches.
Observation in California cores
ponds with the smaller OF these,
where a rainfall of 103 inches, fairly
distributed, insures q crop of wheat.
But different crops require different
amounts. Assuming 10 inches
necessary to q crop, each acre will
require total of $4,000 cubic feet.
One cubic foot of water per second
for twenty-four hours will irrigate
23S acres. One cubic foot per Sec
ond for 100 days will supply 23S
acres sufficient for crop, exclusive
Of rainfall. In India they estab-
lish the theoretical duty Of water
running one cubic foot per second,
at two crops per year on 500 to 600
acres. But that is deemed too low.
Beresford formulates the efficien-
cy of water for irrigation thus:
Each cubic foot entering the head
works of q canal is disposed Of by
absorption and evaporation Ia pass.
ing to the distributing head; by
the same causes in passing to Sec
ondary bitches; by the same cause
in passing to field bitches; by care
lessness of cultivators, and lastly by
useful Irrigation. He should have
considered and included also evap.
grafton when the water is spread
over the land. The total loss is
about Is per cent. by evaporation.
Added to absorption, and the total
losses amount to from so to So per
cent, and by wastefulness it may
increase to 81 per cent. Loss by
absorption should be prevented, loss
by wastefulness reduced by strict
oversight and rigid measurement.
How would he apply the results de-
rived by others experience to Cali
fornia? He replied: One cubic
foot Of water per second through
the year gives 81 $3.50, 900 cubic feet,
which would cover S45 acres ten
Inches deep, and that is the stand
ard duty of water. Suppose in a
district it is available $50 days;
then one foot of water per second
gives IL, $50 feet, equal to ten inches
on 338 acres. At that rate 1000
cubic feet would cover 1886, 900 acres.
Less acreage than this would
Indicate leakage. In India
they get only one-third Of
the theoretical duty of water,
Here, he thought 1t safe to say. not
more than fifty per cent. passing
into the head of canal could be
utilized, hence 1000 cubic feet at
the rate given would irrigate only
1853, 900 acres in $50 days, but the
rainfall in California would, at six
or eight inches per year, restore the
loss, and SO the theoretical utility
of the water would be reached
Now only about 400 acres in O
square mile is usually cultivated, SC
the duty for 1000 cubic feet would
extend to 100000 acres in fact. In
reality, this 1000 feet running all
the year would produce. as in Italy,
two crops per year, and three root
crops. AS to the methods of APP
plying irrigation, the land should
pay for the irrigation with the aid
of the State, pay for the first cost
of bringing the water to the land,
and then it should be the lands in
perpetuity. This he explained as
follows: The State should make
the surveys, do the preliminary
work, and supervise the construc-
ton. When the State has fixed
the location for canals, and dis
trict assumes the construction OF
WOl hSf W abdIlduIc L0e
money therefor, the State should
guarantee the interest on the
money as expended, and continue
the guarantee to certain time, say
five years after the works are com.
plete. The lands should be held
good for the money expended and
the interest, and the State be re-
paid all its outlay. This plan
would require, probably, constitu-
tional authorization. If it is
now unconstitutional, put it
in the Constitution. As
to vested rights, he would
have condemned as necessary to the
States purpose all water interests.
This, he knew, was bold propo-
sition; but it must be met, if irri-
CATION ever becomes a reality in
California. He referred to the
fact that the report of the IrrIga-
tion Commissioners of the United
States for California, had long ago
advised the State to make surveys,
but it had not done so. Only 500
copies of that report had been pub
ished by Congress, and few found
their way to California. Those re-
ports, with his own supplemental
one, had a mass of carefully gath
cred facts which the Legislature
should avail itself of. He quoted
from the report of the Com mission.
ers: "The duty Of the Govern ment
State and National, is to encourage
irrigation. The first step ought to
be complete instrumental
Reconnaissance Of the country to be
irrigated, embracing the sources
ut which irrigating canals ought to
commence, gauging the flow in oil
rivers and streams, and defining
the boundaries into which the
country subject to irrigation is nat
urally divided" When this is
done, said the speaker, the proper
districts should be by Typographical