The Daily Missoulian., 1909-02-14


ground waters, over one-haif is evap-
| Grated into the atmosphere. About
, one third flows into the sea, this pro-
| portion increasing as the mountains
are denuded Of their forests. or the
enormous volume Of water which
| flows every year into the ocean,
| less than two percent is used for irri-
| cation or about 10 percent Of the
| total precipitation In the arid portions
| of the United States. The storage
| capacity of many of our natural reser-
voirs has been seriously reduced in
recent years through the removal Of
their forests. We have as yet de-
veloped no effective means of storing
and controlling flood waters and ev-
cry spring we stand helplessly by
and watch millions of cubic feet of
water go out in the freshets which
would be of inestmable value If 1t
could be held back from the river
channels for even two or three
months In the arid district, on the
catchment areas whose streams are
actually used for extensive irrigation
not more than Is percent OF the wa
ter which Is actually available for
this purpose Is restrained and di-
verted upon the lands which need it.
Water Supply.
From still another standpoint is the
conservation and control of the annual
water supply of the United States of
vital interest to the agricultural in
| dustries. The conservation commits
sion reports that the annual loss
I from floods in this country has now
| reached the astounding figure of $685.
! 10000 Every freshet means destruc-
tive erosion Of the soil. The produce
tivity of the upland farms is being
| constantly reduced by the washing
out OF the soil The commission es-
timares that the annual loss to the
farms alone from this process of soil
erosion reaches $50O.00O, 900, to say
nothing Of the injury to navigation.
Everyone who has had practical ex-
perience on the farm Or orchard
realizes the fundamental importance
of the great sub-surface reservoir of
ground water which holds in storage
the rainfall Of many successive years.
This great reservoir permeating the
ground for hundreds OF feet is the es-
sential basis of agriculture and is the
chief natural resource of the country.
1t sustains forests and all agricultural
crops. and it supplies perennial
streams. springs, and wells. 1t has
been clearly demonstrated that the
quantity of water contained in this
great sub surface reservoir is dimin-
ished by deforestation which converts
larger proportion of the precipita-
tion into immediate runoff and swells
our rivers into torrental floods, while
reducing the supply which is retained
to feed the permanent under ground
sources. Without attempting to re-
view the extense Investigations on
this subject, I will site simply two
instances which have come under my
personal observation.
Watersheds Compared.
Several years ago / made study
of two small watersheds in the Cats
kill mountains of New York whose
streams had been under daily meas
urement by the geological survey for
a number of years. One was rug
ged mountainous watershed, with
steep slopes. generally hard and
impervious geological formation, and
utterly lacking In lakes or other res
ervoirs, but densely forested. The
other lay in more moderate rolling
country with prevailing porous, lime
stone formation and Il large area of
lakes and swamps which formed ma
tural reservoirs This watershed had
been largely denuded of its original
forest cover and was used for farm
ing and pasturage. The two water
sheds We're so near together that all
conditions as regards precipitation
were essentially alike. A careful
analysis of the stream measurements
showed that the flow from the first
watershed was slightly more even and
regular than the flow from the sec
ond. The actual difference between
the cvenness of flow Is not of moment.
the essential point which was vividy
impressed upon me at the time was
that the forest cover on one watershed
accomplished the same results which
moderate topography. soft. previous
geological formation, and large
number Of lakes and swamps accomp
lished in the second watershed,
In California.
My second illustration Is taken from
the other side Of the continent in
the mountains or California. The
Kern river in that state has been in
tensively used for irrigation by large
land companies for over 30 years and
during that period has been subject
to constant measurements of both the
flow and the amount of silt which it
carries. Prior to 1897 the watershed
of that river in the high mountains
was burned over by forest fires prac-
tically every year: it was grazed by
sheep in the war for the open range
until the natural forage was almost
totally destroyed. Since 1897 this wa
tershed has been under the national
forest administration of the federal
government. The number Of forest
fires has been greatly reduced and the
grazing of stock has been limited to