Evening star. [volume] (Washington, D.C.) 1854-1972, 1902-12-17
OF M0L0KAI
FOURTH IN SIZE OF HAWAIIAN
GROUP.
Discussion of the Possibilities of Its
Water Supply for Irrigation
for Sugar Cultivation.


Water supply paper No. II. United States
geological survey. by DIR. Waldemar Lind
gren is a description of the Island of Mol
okai and discussion of the possibilities OF
its water supply for irrigation for sugar
cane cultivation. -
Molokai the fourth in size of the Ha-
waiian Islands is a narrow strip of land
extending thrty-nine miles from east to
west with an average width of a little less
than seven miles, and having an area Of
261 square miles. In 1900 the population
numbered about 200, including 1000 in
the leper settlement established in 1865 on
the northern coast.
Molokai is almost entirely of 1gneous
origin and stands on the submarine plateau
from which the whole northern group or
islands rises. 1t is a volcanic cone built up
in the middle of the ocean by great num-
Der of SuperimpoSed basaltic flows. The
island is, in fact, formed by two volcanoes.
The west end forms one separate and COM
plete, though comparatively low cone,
Mauna Loa, with an elevation of 1,3S2 feet.
The main or eastern part of the island, ris-
ing to nearly 5000 feet in the central peak
of Kamakou, is not of simple a struc-
ture. 1t represents one part, and probably
the smaller part, of a large volcano, the
northern part having dropped down along
great break or dislocation to a depth of
from a few hundred to 5000 even 1850
feet. Thus the great northern pail or cliff
is really break or a fault line which split
the volcano in two. The low peninsula of
the leper settlement Kalaupapa, the only
land of Importance at the foot of the cliff,
seems to be a part of this sunken area,
still above water, on which a crater and
several lava streams yet remain.
The face of this great pail has been
carved into a few deep recesses or alcoves,
over the edges of which the waters of the
upper drainage basins fall in numerous cas-
cades, increasing to magnificent waterfalls
during the rainy season. The surf beats
directly against the foot of the eScarpment.
The southern slope of the island is very
different from the northern Instead of
few great canyons, some forty or fifty
gulches and rav-res form the drainage ways
of the southern slope. These conditions,
thinks DR.. Lindgren, are the natural result
of comparatively recently established
drainage system over the smooth sides of
volcanic cone
A Coral Reef
A coral reef from one-half to one mile
wide fringes practically the whole southern
coast of the island, with the result that the
parts adjacent to the main gulches are
gradually being filled up by mud, and the
island is gradually growing out in this di-
rection. The coral reefs on the northern or
trade wind side are not extensive. A large
AREA VI uttIie SdIlu OCCURS On IHlS she, ana
part of these dunes are consolidated to hard
sandstores, containing peculiar human
looking footprints which, however, DIR.
lIindgren suggests. may be the results of a
Hawaiian propensity for practical joking.
The island possesses the same equable eli
mate that enjoyed by others of the same
group; frost probably never occurs, even at
the highest elevations. The trade winds
are strong, especially during the winter
months and on the northern coast, making
it impossible to effect a landing there dur
ing long periods. There is in general a Wet
season from October to the end of May and
a dry season including the summer months
The west end and part of the south shore
are in the arid zone of the Island. and the
whole northeaSterly part has an abundant
rainfall. There seems to be no data to
prove the assertion that the rainfall
Molokai is decreasing. 1t is no doubt true
that the island formerly supported a much
denser population. This is indicated by
many old garden patches on streams which
are now dry carry water only intermit-
tently. All this is, however, most probably
directly chargeable to the destruction of the
forests and the following irregularity or
disappearance of the water supply.
The soils of Molokai, divided into residual
and sedimentary soils, usually Of great
fertility. The finest body of agricultural
land on the island is situated in the great
gap near the western end, and has an area
of about 1900 acres of deep-red soil un
excelled for purposes of sugar growing. The
principal problem of the water supply of the
island is how to bring the water from that
part which receives an abundant precipita-
ton to this arid portion containing the rich
soils.
As to Irrigation.
In regard to vegetation, the southern side
of the island may be separated into several
zones. There is first the immediate coast
fringe, distinguished by cocoa palms and al
garoba trees "a variety of mesquiD; the bar
rem zone of the south coast; the belt of the
grass lands; and, finally, the high forests.
The forests begin at an elevation of about
800 feet; but the trees are in poor condi
ton and on large areas are dying. 1t should
be observed that the forests on this island
are swampy. Open forests with trees grow
ing on dry ground do not exist The lahua
tree is most abundant. 1t has dark-green
foliage and bright-red f1owery tassels dur
ing the spring months The height is usu
ally thirty to forty feet and around it's
roots cluster ferns which send their wide
spreading fronds up fifteen feet There is
also the oha or mountain apple, and the
koa with its exceptionally hard wood.
Many theories have been advanced as ex-
plantations of the decay of the forest. 1t
has been attributed to cattle, deer and
goats. TO decrease of rainfall and to dis
Of the trees. 1t is evidently true that
for many years the island has been over
stocked But in many canyons where cat
tie can scarcely find their way as we'll as
in some parts of the swamps. the trees
are dying. which indicates that they are
suffering from some insect or fungus. Cat
tie and disease rather than any change in
CLIMATIC conditions DIR. Lindgren holds. are
responsible for the decay of the forests.
Hence. the remedy would be to exclude cat
tie. goats. deer and sheep, and to plant
otto trees. for instance eucalyptus acacia
or Monterey cypress.
The fundamental law governing the water
supply is that the only source of fresh
water is the rainfall. In Molokai the part
of the rain water that goes into the ground
sinks freely through the porous rocks until
1t meets the sea water, upon which it rests
like a sheet and with which 1t must, there
fore, mingle more or less. This ground
water energies salty springs at or near
sea level; as springs. few in number and
unreliable, at elevations of from 1000 to
200 feet there being practically no per-
manent springs up to the 1000 foot level
and as springs of the summit region, feed
ing the permanent streams. The wells so
far sunk have usually degnerated into salt
water wells or have yielded so much salt
in their water as TO impair their usefulness
The permanent streams remain as the
source of water for irrigation.
How to Obtain Water.
The principal problem on Molokai Is how
to obtain water for the irrigation of the
14,0O0 acres of deep soil in the great gap.
Another problem is to obtain water for the
irrigation of the small coast flats occurring
at intervals