Ottumwa semi-weekly courier. [volume] (Ottumwa, Iowa) 1916-1918, 1917-01-19


Geological Survey has just issued It's
latest report on the water flow of the
Colorado river and it's tributaries
charge of hundreds of streams In sec
onG.feet OF water fill the pages. Look
ing at the solid columns Of figures, a
plain citizen was moved to ask an Of
ficer of the survey question.
What is the purpose Of carrying
on this sort of measurement daily
year after year," he queried. "Why
do you keep big force of men read
ing guages and estimating velocities
il the same place on the same river
for fifteen years? Why don't you
measure stream and have done with
it,"
The officer told him story. 81 in
spected a dam down in the far south
west a few years ago." he said. 1T
was an excellent piece of work, well
constructed and perfectly able to hold
the waters that it was designed to
impOund There was only one thing
the matter with it. The water that
it should have backed up wasn't there.
The lake above it, made by its build
ing, was as dry as the great Sahara
desert. 1t was dam without water.
blocking an empty channel. They
We're actually pumping water into the
reservoir in an attempt to keep few
trees alive. There hadn't been en-
ough rain to run down the sides Of
the embankment for eight years..
'Why did they build a dam there
them" the questioner wanted to know.
"Oh. when they looked over the site
and decided to build, there was plenty
of water-a fine river 1t looked like
good thing. There had been plenty
Of water in the river for years past.
Everybody in the neighborhood re-
garded the river as permanent in
again freely enough. But series of
dry years happened to strike the re-
gion. and for those years the river dis
appeared"
OF colrse dam in such situa-
ton Is almost a dead loss. To be Of
any use to settlers and farmers a
water supply must be dependable 1t
must be there every year: because
the country cannot afford to walt
eight years between crops. And in the
land Of little rain, where irrigation is
the only method Of farming. a differ
ence OF five or six inches in annual
rainfall. that would be unnoticed in
the eastern half of the continent, is
the difference between ample water
and drought.
The only way to determine with
real scientific accuracy just what may
be expected from river system in
the way Of water supply is to meas
ure the bow Of the main stream and
its tributaries day in and day out for
a long period OF years Climatic
changes seem to move in long slow
cycles. Only by extended observa-
lions can the real available water sup.
ply be determined with reliability
that is essential before capital should
be risked in schemes for reclamation.
power and other development. And
this extended observation is the work
that the geological survey Is carrying
on in its stream measurements at
I 900 stations.
A case like that of the dam whose
river went dry and whose sides were
hardly dampened with rain in eight
years is Of course extreme and excep-
tional A much smaller variation in
the amount Of water between wet
years and dry years can make just as
effective difference between profit
and loss. II dam is built for irriga-
ton on basis of certain extremes
Of variation in water supply within
five or six years. and the seventh or
eighth year brings a new mark. lower
than any previously recorded, a GER
tain percentage of the crops depend
ent on the reservoir will inevitably
be lost, certain percentage Of the
land reclaimerd will for that year at
least go back to desert The same
thing holds true Of dams built for
power purposes. II mill is built
with the expectation of drawing a GER