Graham guardian., 1917-01-19
Relative to Water Problems
Given by Engineer
J. B. Spiegel

| wv ~ 80 WI ~ vow W AA>'A - AA' ~
came to the valley, the editor of
THE GUARDIAN suggested that |
let him know about my work and
it's progress in general. At the
time | was new to the country
and its people and just commenc-
ing the work snd so not much
could be said.
1t is now three years nearly
since the stream gaging on the
Gila river in Graham and Green
lee counties has been in progress
in a detailed way, but the people
do not seem to understand the
purpose of the investigation or
realize the benefits to be derived
therefrom.
One of the common questions
frequently asked me is What is
this all for?" A brief answer
would be For you," but | shall
endeavor to explain the problems
and the ways and means of gath
ering data for their solution. In
cidentally a few suggestions will
be added.
Before proceeding with the
discussion, | shall explain some
units commonly used pertaining
to water problems, such as will
be discussed. The three prin-
cipal ones are: The acre foot,
the second foot and the miners
inch. The first two are definite
and are definitely and directly re-
lated to each other; but the
miners inch varies somewhat ac-
cording to the Interpretation of
the definition. quote the para
graph devoted to it in Johnson's
Theory and Practice of Survey
ing"
This is an arbitrary standard,
both as to method and as to
volume of water discharged. 1t
rests on the false assumption
that the volume discharged is
proportional to the area of the
orifice under a constant head
above the top of the orifice. Its
use grew out of the necessities
of frontier life in the mining re-
gions of the West, and should
now be discarded in favor of
absolute units. The miners inch
is the quantity of water that will
flow through an orifice one inch
square, under a head of from
four to twelve inches, according
to geographical location. Even
if the head above the top of the
orifice be fixed and a flow Of 144
miners inches be required, the
volume obtained would be 3.3, AZ,
or At cubic feet per second, ac-
cording as there were 144 holes,
each one inch square, one open
ing one inch deep and 144 inches
long,or one opening IL inches
square. the tops of all openings
being 5 inches below the surface
of the water. This simply illus
trates the unreliable nature of
such a unit. = When the
miners inch can only be defined
as a certain number of cubic feet
per minute, it is evidentally of
no longer service and should be
abandoned. The method by weirs
is more accurate, and could almost
always be substituted for the
method of orifces." In Arizona
the miners inch is equivalent to
lao of a second foot.
A second foot is a cubic foot
per second. An acre foot is the
amount Of water that will cover
an acre of level surface one foot
deep. Roughly, a second foot is
equal to two acre feet per day.
If a cubic foot flowed every sec
ond in "a hours, sc, 400 second
feet of water would have passed.
There are 43, $50 square feet in
an acre and this number will
go into sc, 400 nearly twice, show
ing that a second foot is equal to
about two acre feet per day. The
latter unit is used in expressing
large quantities of water. For
stream measurement, the second
foot is used.
In another article | shall write
of the various methods more
commonly used for measuring
water.
7 r. SpIECE1.