ment except levee construction is
emphasized. The present channel of the river will not carry without
damage the amount of water recently thrown into it, and while it is
important to provide regulations which will in the future prevent
encroachment, and which will correct the evils now present along the
channel, these measures can not, operating of themselves, give relief
from flood devastation. Immunity from flood destruction in the Passaic
must come, if it ever comes, from the construction of flood-catchment
reservoirs in the uplands.

It is not necessary to spend any great amount of time in determining the
cause of floods upon the Passaic. A review of the flood history of this
river shows that in every case floods arise from extraordinary
precipitation. High waters occur through the melting of snows and during
periods of abundant rain. The heavy floods which have been regarded as
extraordinary are clearly the result of unusual conditions of
precipitation. The river carries the usual flood waters, and no damage
is done until the water poured into it is far beyond its carrying
capacity. Therefore the provisions which are made for preventing damage
by floods must, if they be effective, be designed to meet extraordinary
conditions, and means which would prove effectual in ordinary cases
will not stand the test. In order to appreciate the extent of the flood
in the lower valley it is necessary to visit the flooded area and
observe the points of flood height. Unless one does this he will be very
readily deceived when he considers means of flood prevention.

FLOOD CATCHMENT.

Among the highland tributaries of Passaic River there are three
principal areas where storage reservoirs for flood catchment may be
placed: (1) The Ramapo, Wanaque, and Pequanac drainage basins, from
which the waters are carried into the central basin by Pompton River;
(2) the Rockaway drainage basin, and (3) the upper Passaic drainage
basin. The remaining principal tributary of Passaic River, the Whippany,
is not well provided with storage reservoir sites. The combined capacity
of catchment reservoirs which could be constructed in these drainage
areas is considerably more than the volume of the heaviest known
rainfall, that of October 8-11, 1903.

In the description of reservoir possibilities in the following pages the
data with reference to many of the basins are computed from planimeter
and other measurements, the United States Geological Surv