The Hawaiian gazette. [volume] (Honolulu [Oahu, Hawaii]) 1865-1918, 1891-05-12
GREAT ENGINEERING
WORK.
The Hawaiian Sugar COmpany's
Ditch at MakaweH, kauai.


Sugar Co.'s ditch on the 18th April,
10 the lands OF the company at Maka-
well, Kauai, is one OF the most essential
factors in the building up OF the large
plantation Of the Hawaiian Sugar Co. at
MakaweH, thus adding another large
element Of wealth to the Hawaiian ISL
ands, and good prospects OF pecuniary
success TO the energetic promoters of
this enterprise.
The Hanapepe stream from which the
water is taken, is one OF the largest
streams on the island OF Kauai, and it is
less subject to fluctuations than many OF
the streams, owing to Its favorable situa-
ton and large watershed. Its numerous
branches collect the water from the
center and highest parts OF the island,
and converge to a single stream some
nine miles from the sea. At this point
the two main branches come together,
and 1t is at a point five hundred feet
above the junction OF these two branches,
on the east fork, that the beautiful
Hanapepe Falls, PSI feet high, are stu
ated.
The main watershed of the river lies
directly in the path OF the trade winds,
and while rain may be and generally is
falling a good portion OF the year at the
falls and higher up, scarcely any reaches
the sea in the vicinity OF Makaweli; a
climatic condition peculiar to many por-
tions OF the Hawaiian Islands, on the
western and southern slopes.
The porous character of the rock on
the island is also an important factor in
the steadiness OF the amount OF water in
the Hanapepe stream, storing up the
water in times OF overplus and giving it
out in times OF drouth. This was demon
strated during the progress OF the work,
as in the heavy side hill cuttings in
rock, and in the tunnels, considerable
increase OF moisture from the sides of
the cuts, in MANY places, and from the
roof of two OF Il tunnels, was noticed
after heavy I'm. This would be a
small amount, OF course, at any one
point, but when collected from large
watershed would be a respectable per-
centage OF the total. This refers simply
to the deeper percolations and not to the
natural drainage OF the surface soils.
The general character of the canyon of
the Hanapepe stream is very rugged,
with precipitous sides, and, in many
places, noticeable at the canyon station
and lowest pipe crossings, has nearly
perpendicular rock bluffs OF about 600 feet.
The very ruggedness of the canyon has
been the chief reason in past times, OF
preventing the higher waters of the
hofy,sr fol 70, build
sugar plantations on the fertile lands
lying in a broad circle near the sea. In
fact the scheme had been by many
deemed impracticable, but after the
lease OF the lands came into the hands
of Hon. IL. p. Baldwin, the pioneer on
the Islands in the matter of laying large
pipes for irrigation, and his associates,
constituting the Hawaiian Sugar Co.,
the practicabiiity of the scheme has not
only been demonstrated, in the building
of the ditch, but asystem capable OF irriga-
ting 600 acres of very fertile cane land,
by the cheapest known method, gravity,
has been built at a cost not exceeding
the first cost OF first-class pumping
plant, doing equal duty and pumping to
a height of 100 feet.
The water from the east fork is taken
out at the foot of the falls, carried across
the west fork, where it meets the waters
of that fork, taken out d few hundred
feet above the junction. Two low ma
sonry dams built across the two branches
at the points of divergence will insure all
the water of the river at its lowest stages.
This amount during the past year has
not fallen below 30 cubic feet per second,
an amount OF water capable OF irregating
from , 900 to 5000 acres Of sugar cane.
The capacity OF the ditch is 90 cubic feet
per second, or 216,000 gallons per hour.
The ditch is 1879 miles long from the
head dams to the reservoir.
The difficulties of the conception OF the
best position OF the ditch, from an en-
gineering and therefore economical
point of view, all lie in the first 634
miles, or from the head dams to the last
pipe crossing of the Hanapepe stream,
In this distance there are 16,100 feet of |
ditching, u, 800 feet OF fuming, 500 |
feet OF steel piping and ,017 feet of tun-
neling. There are six inverted syphons !
in this distance. The first three are
short, crossing side gulches, the last |
three crossing the water from one side OF |
the main canyon to the other, to pass |
precipitous bluffs or to obtain more IA
vorable ground for ditching.
The longest Of these syphons is l 1923
feet, and the deepest 400 feet. The
diameter of the pipe is 40 inches, of
steel OF 10000 pounds tensile strength,
and varying in thickness from s to 5-16
of an inch. The maximum strain is
1900 pounds per inch, or about 4 the
strength of the pipe. The pipe
was thoroughly coated inside and out
with heated preparation of asphaltum
and coal tar, laid in q trench in the
ground or on prepared trestle work, riv
eted continuously in sections, and COW
cred with earth or lumber to prevent
the sun from melting the asphaltum Or
expansion. Pipe similarly pre-
pared and laid in California has been
Iound to be as good as new after doing
fifteen years service There is good rea-
son to believe that fifty years IS not too
ong to expect for the life of such pipe.
Four substantial iron bridges carry the
pipe across the river. Three of them
ire of 100 feet each, the other of 140 feet
ipan. The flume of which there will be
.ltogether about 234 miles, consumed
bout 600, 900 feet of lumber, and is very
built OF redwood.
OF the ditching about two miles were
ut from the solid rock, the remainder :
,eing in the ordinary red earth of the :
Five-sixths OF tine last 61a |
niles or from the last crossing of the /