Evening bulletin. [volume] (Honolulu [Oahu, Hawaii]) 1895-1912, 1911-09-09

Vuh OlC vi tuC hhoos hAAPOh sohs Os.~s
IL that different system Of measure
ment shall be taken up here. At the
present time there is only one way
for, expressing both flow and capacity,
and that Il by gallons. n you speak
Of a stream as q million gallon one.
you mean that during ewentyafour
hours one million gallons Of water
will Cow through It's banks past o.
given point This term Of gallons 10
also used to, express capacity, for you
speak Of million-gallon reservoir.
This last way Of using It IL the cor
rect one. as II gives you some idea
Of the quantity Of water that you
have collected In one place. When
you come to use II for the flow Of
q stream. however, II IL rather out Of
place. for no connection between the
amount Of water coming down the
stream and the quantity needed to
irrigate an acre Of land can be made,
except by the rough and ready moth
DDS In use at the present time.
The basis Of measurement which Is
In use on the mainland and in other
parts of the world IL that Of acre.
feet and second-feet. The first term
means the quantity of wseer that is
needed to cover an acre Of ground
one, foot deep with water, or a guam
tjty Of water equal to twelve inches
OF rainfall. The term second.foot is
Al abbrcviation for one cubic foot Of
water q second, and, as the full name
implies. means that every second one
cubic foot Of water will pass a given
point as the stream flows.
/ This may sound somewhat confus-
ing at hrst. but when II is seen how
easy It is to get some, idea Of how
much water a stream will give for
irrigation purposes when you have
Its flow mentioned in second-feet, you
may change your mind. Take a
stream that has a flow OF one million
gallons during every twenty -four
hours. According to local knowledge
this amount Of water Is enough to
irrigate one hundred acres of cane.
Beyond this fact. however. very little
is known.
Say that instead OF saying the
stream mas a flow of one million gal
Ions. II Is noted as a stream that
has flow Of l.55 second feet, which
means the same when worked out as
one million gallons. This means that
every second there is cubic foot Of
water available for irrigation pur-
poses. Now It Is known that one
second-foot Ia equal to two acrc-feet.
taking this out further. Il will be seen
that stream with flow of one Sec
0nd-foOt Ia capable Of covering two
acres Of land with foot Of water
every day. This also means that our
original stream has supply Of water
that is equal to twelve inches Of rain
over two acres.
| It has been worked out that a
: million gallons iof water, is equal to
F., three acre-feet, ~ following along the
1 lines that the million gallons may be
called '1.55 second-feet. :. Working
along lines such as these. II will be
seen that an idea Of something def
| mite can be obtained between the con-
| nection Of the flow Of the stream and
the rainfall which this representa-.
For instance. 1t has been stated be.
fore that million-gallon stream will
irrigate one hundred acres OF cane.
Worked out by second-feet, we have
Il that the stream, when put on the
ground, equals 1872 inches OF rainfall
in the year.
Less Of Water.
As previously reported in The
bulletin, Mr.. Martin has been
working on the amount OF water that
is lost In ditch. and has found 0u|
that there is hardly one OF the bitches
here that does not lose a certain
amount Of water during its length
In some cases 1t has been found tina,
ss much as forty per cent is lost
| BY means Of his observations hi
can tell the owners Of the stream
Just at what place they are losing
the water. and they will then BE- able
to get to work and remedy It. Their,
are men on two Of the other islands
all doing the same work and report
Ing back to Mr.. Martin, SO that he car
work upon the data. A yearly repor
Is published In all Of the States. and
from this the farmers and irrigation
men can see Just exactly what watel
tthey may expect during certain peri
ODDS Of the year. Many Of the planta
tons here have ordered current me
ters and will make calculations To-
themselves. There has been no re
port published as yet. but there vii
be one at the end of the present year
when Mr.. Martin has all his data to
gether. - ' .,.
The work Of the department doe
not consist Of sitting inside and max
Ing calculations. Every stream an
ditch has to be visited at all time
OF the year and the various calcula
tioAs made. From time to time MI
Martin expects to be able to give on
some valuable Information in connec
ton with our, water supply here.
JI - :