Honolulu star-bulletin. [volume] (Honolulu [Oahu, Hawaii]) 1912-2010, 1915-04-10
CITY ENGINEER
OUTLINES PLANS
FOR MORE WATER
Scheme Explained to Increase
Nuuanu Supply at Mod
crate Cost

CITY Engineer WhuchOusc has a
definite plan for materially increasing
IIOnOlulu's water supply without the
purchase OF any additional water
rights He has outlined his plans
which deal with the Nuuanu situation
in the following report to the super
visors:
! hand you herewith report on the
matter Of improving the Nuuanu wa
ter system so as to make available
for consumption the millions OF gal
Ions OF water which now 20 10 waste
without even generating electric pow
or.
At the present time this system
consists Of four earth reservoirs with
connecting pipe lines:
No / capacity u ,000,00O gals; elev.
high water 1913 II.
No 2 capacity 100000 gals; elev.
high water 739 f.
No. 3 capacity 10,0O0,0OO gals; elev.
high water SAG It.
No. 4 capacity 625 O00. 900 gals; cICv.
high water 1923 fl.
No. is a distributing reservoir on
ly and receives water from Nos. 2, "
and 4. IT receives no drainage from
the surrounding country.
1t is connected to Nos. and by
Is in. c. !. main and to No. 4 by
so in. steel and 80 in. wood staVe pipe
line
The Is in. also connects with the
weir at Luakaha.
II has been determined that the
Nuuanu watershed is good for 1900
600 gals day throughout the year.
At the present time conditions are
such that an average Of 100000 gals.
per day goes to waste out Of No. 2
spiliway.
The trouble in the valley is not lack
OF storage capacity, as No. has
capacity Of 625,000,O00 gals, but is
due TO the topography which delivers
the bulk of the water to Nos. 2 and
which are Of very small capacity.
There are two wheels at this sta
ton, one run by the low head from
No. and 3, and the other by the
water from No. 4. With this arrange.
ment it is impossible to conserve wa
ter in No. because It is continu-
ously drawn on for power even when
water is. wasting out of Nc. 2.
The difficulty is not entirely in the
valley because even without using
the water for power purposes it is not
possible to get il down to consumers
with the present distributory system.
The problem resolves itself into MI
nor problems, the first Of which is
to impound the water 50 as to save
every drop OF the runoff from the wa
tersheds of the various reservoirs.
The second problem is to get the
water to the consumers by means OF
proper pipe lines.
In our. case, however, there is the
additional problem of making use of
the water for the generation Of cleo
tricity.
The first problem may be solved in
several ways:
ta) BY intercepting bitches and
pipe lines on both sides Of the valley,
water which now goes into Nos 2 and
3 may be diverted into No. 4.
(b) By excavating Nos. 2 and 3
may be enlarged so as to double their
capacity.
(c) A compromise of "a and 3D.
that is, a partial development of,
No. ! watershed and the enlarge
ment of Nos. 2 and 3 to take care
OF the balance of the r1nof.
The second problem is much more
simple and can be solved by the lay
ing OF additional mains from No. i
down into the city.
The additional problem Is in con.
nection with the use of the water for
generating electric current.
. One thing TO be remembered is that
a pipe may be large enough to fur
nish the required amount of water
for domestic use but for power pur-
poses pipe several times the capa-1
city is necessary.
This is true at the present time In
Nuuana. The Is in. connecting Nos.
2 and to No. ! is amply large to
supply No. i, but as power line 1t is
insufficient. The point ] wish to make
is that the cost of developing water.
power should not be charged against
the water works except under the con-
dition that the electric light depart
ment pay a rate high enough to pay
interest on the investment and pro-
vide a sinking fund.
AS il stands the 80 in. from reser-
voir No. 4 is sufficiently large to de-
velop over 1000 b. p. but the water is
lacking Tin the reservoir). So that
to get the benefit Of the water from
GO