Omaha daily bee., 1902-04-18
ABOUT IRRIGATION
Department of Agriculture Issues a Bull
etin Of Great Value.
METHODS OF PREVENTING wASTAGE
Available supply of water Could Ac-
comppsh Much More Good ~ Care
~ Taken Of It's Dis
tribution.
C,rom a star Correspondent

WASHINGTON, April 17.-(speclal.)-The
second annual report, bulletin lO4, OF the
irrigation investigations Of the United
States Department OF Agriculture, under
the direction OF Elwood Mead, has just been
issued. 1t contains 1874 pages and is fully
illustrated. The leading subject Of the in
vestigation is TO determine the quantity o.
water used by farmers in various parts Of
the arid region. In his review OF the work
for the year 1900 MIR. Mead says that farm
ers need an approximate knowledge Of the
duty OF water in order to make intelligent
contracts for their supply. II is needed by
the engineers and investors in order to
properly plan canals and reservoirs. with
out this knowledge every important trans
action in the construction of irrigation
works or in the distribution of water there
from is very largely dependent on individ-
ual judgment or conjecture. Rights to use
Of water cannot be impartially settled un-
less at least an approximate knowledge OF
the duty Of water Is available.
Many works have been planned on the
assumption that water enough to cover land
to a depth Of one foot during the season
would bring crops to maturity, while the
average depth OF water used, measured at
the points Of diversion, was over four feet.
A large part OF this water is lost from the
canals between the headgates and the land
irrigated by seepage and evaporation. This
loss has been found to be much larger than
had been supposed, the average Of all the
measurements reported showing a loss of
2.47 per cent per mile of the water taken in
at the heads Of canals. The lowest meas
urement reported 10 about a quarter of l
per cent per mile, while the largest Is
more than 6 per cent per mile. Slight i'm
provements often reduce greatly the loss
due to seepage, II the places where this is
the most serious can be pointed out. Tne
Investigations in the field have this object
in view. In many places such work would
result in a doubling OF the water supply.
While the loss from canals is in itself a
serious matter, the greatest harm is often
done to low-lying lands which become too
wet to grow crops. or. IL the subsoils con-
tain injurious salts these are brought to
the surface and vegetable growth thus
made impossible. There will. therefore, be
a double saving from improvements which
prevent largo losses of water from canals.
The reports give the methods employed in
different parts Of the west for reducing
these losses.
Need of Storage.
All reports emphasize the need of stor-
age not only for increasing the area culti-
waited. but to properly farm the areas al
ready under cultivation. An important ques-
ton in the construction Of storage reser-
voirs is the amount and character of the
silt carried by streams whose waters are
stored. Investigations of this question have
been begun in the southwest, but it's study
will have to be carried on for a number of
seasons before much definite information
will be available. The progress report con-
tanned in Bulletin 104 deals with the
methods used for preventing the deposits
Of silt. This is sometimes ACCOMPLISHED
by making settling basins in the feeders
at short distances above the reservoirs.
thus checking the velocity of the stream
and permitting a deposit of the greater
part Of the silt. Sluicing reservoirs to re-
move the silt have not yet been attempted
in connection with this investigation.
There has been much demand for in
formation in regard TO pumping water for
irrigation. In many places 1t is believed