, 1890-04-08
DUTY OF WATER.
An Extremely Valuable Paper by
Engineer Mead.
Discharge Per Second to Irrigate a
Stated Area.
The Result of Measurements on
Cat and Potato Crops.

lerrltOrlal Engineer heau contributed
to the session Of the Wyoming Academy
of Arts, Sciences aud Letters last fall a
very valuable paper on The Duty of Wa
ter" Publication of the vital points of
the essay at this time cannot but result in
practical benefit to all irrigators and a re-
sumo is given.
The data was gathered in the field by
Mr.. Mead and is absolutely correct,
The amount of land on which a stated
quantity Of water will insure full crops is
designated for practical purposes IN one
OF three ways:
L. The discharge per second, or per
minute, Of Il continuous flow during the
irrigating season.
9. The total volume used during the
season.
8. The depth to which the quantity
used would cover the surface on which
applied.
The engineer says the first is most gen
orally employed and the duty" is ex
pressed by stating the number of acres
which a miners inch or cubic foot of wa
ter per second of continuous discharge
will irrigate-a convenient form of state
ment because it agrees with that used in
the allotment of water to bitches and OF
the distribution thereof. Taken without
some additional limitation. however, it is
an indefinite term, since the length Of
time of the flow is not stated. To make
it specific there must be some definition
of the duration of the irrigating season.
The paper stated that the principal
difficulty, however, is the lack of knowl-
edge as to the quantity used; and this
cannot long continue, as the necessity
for reliable data becomes each year more
imperative under our present laws; 1t
should be at the command OF the courts,
since the actual requirements of the lands
should be the basis of allotments of water
in the water right district. An approx
mate is indispensable to both the terri
torial engineer and the water commission
er IN performing their duties. Nor is the
commercial importance to water buyers
or water sellers of less moment. 1t %
not onlv a matter of dollars and cents to
kuow whether an inch will lrriRate an
acre, or a cubij foot per second eighty
acres, but it is impossible in the absence
of some reliable approximate Information
to place its distribution on a business
basis. Up to the present, he says, about
H. onIr or;,a.;op boa haan tha nnoerta,n
and unreliable one of personal judgment.
But few tests have been made. aud their
results are not generally known. Yet
millions of dollars have been invested in
bitches aud in the purchase OF water
rights aud allotments OF hundreds ofcubic
feet Of water have been made by our
courts.
Mr.. Mead quoted in this connection
from the opinion Of a judge to prove the
dilemma in which the courts find them
selves, and then proceeded with a highly
interesting account of his experiments
with the Wyoming kilometer. a seli-reg-
istering apparatus of his own devising to
solve the problem OF duty" present
ing diagrams and tables by way of illus
tration and demonstration. His expert
ments during the past season were with
oats and potatoes, the results being as
follows:
DAT CROP.
Total number of cubic feet of water.
used. Lose, 235. SIS.
Time employed, 54.5 days.
Am punt of surface, 1887 acres.
Average discharge for period used, 3.79
cubic feet per second.
Equivalent average DISCHARGE for irri-
eating season MAY, June, July, August,
1872 cubic feet per second, or al euuiva-
lent duty of one cubic foot per second
for a continuous discharge OF 80. acres.
POTATO cRoP.
Total number of cubic feet of water
used, 323, S25.
Time employed, &c hours.
Area OF surface, 7 acres.
Average discharge for period used, 2.5
cubic feet per second.
Equivalent average discharge for lrri-
eating season. May, June, July, August,
O.O3O5 cubic feet per second.
Or an equivalent duty of one cubic
foot per second for one continuous DIS