fall of the water level with tide.
may be used but should be located in
deep water beyond the surf. They must
sheltered bays, harbors, lagoons, or
be positioned vertically and be off
estuaries can be supplied by intakes
the bottom but still beneath the water
constructed in the same way as fresh-
surface at low tide.
In this way
water surface intakes.
foreign materials in the water which
islands where there is insufficient
surface and ground water, and on or
distillation equipment will be largely
The rigid pipe type intake
can be paced on timber supports and
constructed as follows:
piling or riprap.
(1) Salt water wells.
anchored can support the intake screen
wells should, If possible, be used in
in much the same manner as in surface
preference to offshore intakes. Wells
waters (fig 9). A rubber suction hose
can be dug to tap fresh or salty
can be used to connect the rigid pipe
This eliminates the
problems caused by tides, surf, and
supported beneath the float.
shallow water close to shore.
wells have an added advantage in that
they can be constructed back of the
In regions such as
Driven and jetted wells
may also be used effectively at beach
abundant rainfall and rapid surface
source for the inhabitants, however,
(2) Offshore intakes.
the quantity of water available may
intakes are sometimes required because
of lack of time, men, or equipment or
needs of both the civilian population
because of coral conditions which
and the military.
Rainwater as a
prohibit well construction.
source may be sufficient for small
of either the rigid pipe or float type
units for limited operations, but
Float type sea water intake.