The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1885-1921, 1906-02-07

months quicker, an item more than Off
setting the increased cost.
| PROGRESS OF THE WORK.
At present the work on the big reser-
| earthwork on the Eva end is about
completed and the trenches for the
core-walls have been dug past the bed
of the Nuuanu stream. Nothing has
been done on the Waikiki end of the
work since the ground for the spillway
| was sluiced off some time ago and filed
all the Honolulu taps with mud, ex-
cept to survey for a few yards of
railway line up to Lulumahu gulch for
| the transportation of rock for the rip
| rap lining of the dam.
The earth for the Eva end of the
! dam is being conveyed from the higher
hillside by an aerial tramway with
self-dumping buckets, acting through
gravity. Each bucket brings down
third of a ward of red earth and scat
tiers it along the embankment wherever
desired This tram is the idea of Mr..
J. H. Moragne, engineer in charge for
the contractor, and is now being pat
ented Another labor-saving device,
not patented, is employed in pounding
this earth into solidity, herd of SheU-
land ponies being driven up and down
over the loose dirt, tamping the whole
firmly into place.
SEVERAL SPRINGS DEVELOPED.
The excavation for the core-wall in
the guIch of Nuuanu stream has tapped
number of artesian springs, the
water from which is delaying work
considerably in putting in the cement
core wall which is to strengthen the
dam at the point of greatest pressure
The highest portion of the dam will be
across this gulch and the corewall is
TO be built M from thirty feet below
the level of the stream, shutting off
the flow from the uncovered springs.
This concrete, which will be 156 feet
long and four feet thick, will
strengthen the wall so that pressure
ten times greater than a brimful reser-
voir can be withstood. At this point
the dam is to be 400 feet thick at the
bottom and forty across the top, while
in other portions the thickness varies
down TO 100 feet
DEVICES FOR SAFETY.
The big waste pipe, So inches in
diameter. has been put together and
the lowest effiuent pipe above 1t IS
ready for the concrete which will bind
these two together. Both pipes are of
wooden slaves and will be encased in
concrete and reinforced with heavy
expanded metal 1t is around these
pipes that the greatest danger VIII be
found and elaborate safety devices will
be used to prevent any possible leak.
Along them. at intervals of thirty feet,
concrete collars will be built, extend
ing into the solid dam eighteen inches,
thus shutting back any water which
might percolate through.
The waste pipe is the lowest, and
will be used to drain the reservoir
when necessary and also to supplement
the sixty-foot spillway on the WAIKIKI
end of the dam in case of any possible
clou8burst when the work might be
threatened. Above this will be the
three effiuent pipes, at equal distances
apart from the bottom to within flt-
teen feet of the surface. These sup
ply the water for the water MAINS
which passes first through the gate
chambers screens. The gate chamber
is tower built within the dam from
the bottom and protruding some
twenty feet, in which the machinery
for controlling the big "a and 80 inch
valves in the pipes are situated.
A foot of riprap on the inside will
complete the dam, which will at high
water be eight feet above the surface.
THE STORAGE CAPACITY.
When full there will be 4OO,0OO,00O
Gallons of water in the 70-acre reser-
Yoir. drained from 1225-acres of
catchment area The water from the
Lulumahu gulch, now the principal
source of the city supply, will be
turned back up Nuuanu valley and
emptied into the reservoir just above
the spillway, From the Eva si an
ls-ineh pipe pierces the dam. through
which the water from Malulu Will
eventually pour into the big lake.
For four thousand feet back, nearly to
the Pail brink, the water will be piled
up. in some placed sixty feet deep.
This water will be purer than that
now supplied to HOnolulanss. chemical
tests taken at the scarce showing the
entire absence of animal pollution and
much smaller proportion of organic
matter than in the present reservoirs
Nos. l, , and 3.
1On fal-a