between Copperas and Kanouse mountains, just below the village of
Newfoundland. This point has been considered an excellent site for the
construction of a dam, and in the installation of the present
water-supply system of Newark it is proposed that the entire valley in
which Newfoundland is situated be overflowed. The site is one of the
most advantageous known for the creation of a flood-catchment basin. If
a dam 50 feet high were erected across this gorge, a lake would be
formed which would have a surface area of 3.15 square miles and a
capacity of 3,267,200,000 cubic feet, equal to a storage of about 30.5
inches on the 46.12 square miles of contributing drainage area. This
would afford complete protection in case of a sudden run-off of 12
inches, would provide for the supply of the city of Newark without
greatly disturbing the present storage system of that city, and would
still yield a large amount of water for compensating purposes in dry
seasons.
The construction of Newfoundland reservoir would be very expensive, as
it would involve the flooding of Newfoundland Village, in which there is
considerable improved property. About 3 miles of the track of the New
York, Susquehanna and Western Railroad would be submerged, as well as a
considerable mileage of macadamized highways. On the whole, however, the
Newfoundland reservoir project is the most favorable which can be found
on the Pequanac Basin. There are above this point numerous reservoir
sites, but their combined capacity would not be equal to that of the
proposed Newfoundland reservoir, and the construction would be probably
quite as expensive.
_Stickle Pond reservoir_.--Below Newfoundland there are few available
places at which water could be stored. Stickle Pond is probably the best
adapted of any of those available. If a dam 1,050 feet long and 80 feet
high were erected across the river about 1 mile below the present outlet
of Stickle Pond, a lake would be formed having a surface area of 422
acres and a storage capacity of about 800,000,000 cubic feet. The
drainage area above this dam would be approximately 4 square miles. This
is a comparatively small amount of storage, yet it would provide for all
flood catchment in that comparatively limited area and would be of
assistance at times in compensating the dry flow of the Pequanac.
ROCKAWAY SYSTEM.
Rockaway River offers a greater number of available reservoir sites than
either of the other highland tributaries of the Passaic. Some of the
reservoirs which could be constructed could be used solely as catchment
areas to hold back flood waters, while the capacity of others would be
so much greater than any single flood run-off that they might serve also
as compensating reservoirs. A large dam is now in process of erection at
Old Boonton, conserving a considerable amount for the water for the
municipal supply of Jersey City. This reservoir can not be depended upon
as a flood-catchment area, as it will be the aim of those in authority
to maintain the water in it as high as possible.
_Powerville reservoir_.--A short distance above Boonton the erection of
a comparatively small dam would flood a large, irregular, flat basin
having an area of a little more than 4-1/2 square miles and extending up
the Rockaway Valley to Rockaway Village, up Beaver Brook to Beech Glen,
and north and south for considerable distances. The probable capacity of
this reservoir has been estimated, and it is fairly certain that it is
considerably more than would be sufficient for flood catchment. Its
construction would, moreover, improve the entire valley and be of
advantage to many interests.
The northern New Jersey flood commission has selected for investigation
a reservoir site on Rockaway River at Powerville. By the erection of a
dam across the stream at this point, 28 feet in height and 470 feet
long, a reservoir 4.6 square miles in area, with a capacity of
1,565,000,000 cubic feet, would be afforded. The drainage area above
this point is 114 square miles. The cost of such a reservoir is
estimated at $600,000.
North from Powerville, near the confines of the proposed Powerville
reservoir, there is an available reservoir site along Stony Brook. By
the erection of a dam 1,100 feet long and 120 feet high a lake would be
formed 645 acres in extent, which would serve as a flood-catchment basin
and a compensating reservoir. This reservoir would hold approximately
850,000,000 cubic feet. The construction of a reservoir at this place
offers no engineering difficulties, and the project may be regarded as
extremely favorable.
Dixons Pond, west of Rockaway Valley and northwest of Powerville, is a
small sheet of water which lies in a valley which might be flooded to a
greater height. By the erection of a dam 450 feet long and 30 feet high
a lake of 136 acres would be created, which would form a part of the
flood catchment and compensating service.
_Longwood Valley reservoir_.--A large storage basin is afforded in
Longwood Valley which, if developed to its full extent, would extend
from a point about a mile below Lower Longwood 7 miles up the headwaters
and reach to about 1-1/2 miles above Petersburg. An alternative
proposition is afforded which involves the submerging of less than half
this area.
A dam 800 feet long and 55 feet high might be erected across a gorge
about 1 mile south of Petersburg. There would be formed a lake of about
1.247 square miles, or 800 acres in extent. The hamlet of Petersburg
would be submerged, but the damages from the destruction of improved
property would not be very great, as the improvements and the land are
not especially valuable. This reservoir would have a capacity of about
964,000,000 cubic feet and the surface would be at a height of 800 feet
above sea level.
The alternative plan, that of using a longer stretch of the valley for
reservoir purposes, would involve the construction about 1 mile below
Lower Longwood of a dam 1,300 feet long and 110 feet high. The reservoir
thus formed would be 1,900 acres in extent and contain approximately
3,447,000,000 cubic feet. The drainage area above this dam is limited,
and if the reservoir were drawn down to an amount equivalent to 15
inches upon the drainage area there would still remain an enormous
amount of water which could be used in a compensatory way to tide over
dry seasons.
_Splitrock Pond._--By erecting a dam 550 feet long and 30 feet high
across a gorge at the outlet of Splitrock Pond, a lake could be formed
having an area of 625 acres and adding to the present storage capacity
of the lake an amount approximately equal to 475,000,000 cubic feet,
equivalent to 38.75 inches on the drainage area.
Thus it is seen that if this reservoir were drawn down an amount
equivalent to 15 inches on the drainage area, which would without doubt
give sufficient protection from all floods, there would still remain a
storage capacity of 23.75 inches for compensating purposes in addition
to the amount now available in Splitrock Pond. This project is one of
the most attractive in the Rockaway Basin, as the damages which would be
caused by flooding would be, comparatively speaking, nil. The property
is, however, now owned by the East Jersey Water Company, and is prized
highly as a reservoir site by that corporation.
UPPER PASSAIC BASIN.
_Millington reservoir._--There is an area of swamp land, comprising a
part of the drainage area of upper Passaic River above Millington, which
is known as Great Passaic Swamp. It is bounded on the south by a long,
narrow trap ridge known as Long Hill, the summit of which ranges from
400 to 500 feet in elevation, or roughly 200 feet above the border of
this swamp. To the northwest the land rises gradually toward Trowbridge
Mountains, while to the northeast is the terminal moraine. The outlet of
Passaic River at Millington is by a narrow gorge, which offers natural
facilities for the erection of a dam.
The whole situation is exceptionally good, and the surface of a
reservoir might be fixed at any elevation between 240 and 300 feet above
sea level. With the surface of the reservoir at 300 feet a dam 1,600
feet long and 90 feet high would be required. This lake would have an
area of 28.46 square miles. The drainage area above Millington has,
however, an area of only 53.6 square miles, and the proposed reservoir
would therefore cover more than half of this. Therefore the conservation
of so large a quantity of water would not be necessary nor advisable,
unless the beautifying of the surrounding country were an object to be
taken into consideration, which might be profitable.
A better project, however, would be to construct a dam at Millington 900
feet long and 50 feet high, the crest being about 260 feet above sea
level. There would be formed a lake with an area of 19.41 square miles,
and a capacity of 1,477,600,000 cubic feet, equal to 9.864 feet on the
drainage area. This project is too great for the necessities here
presented, and would not be wisely considered unless it were found
advantageous to improve the country generally as a place of suburban
residence. The land which would be flooded with the reservoir crest at
260 feet is of a wet, swampy character, and its value for agricultural
purposes is somewhat doubtful. Such construction would involve the
flooding of 13 miles of road, which, however, would not involve a great
loss of invested capital, as the roads generally are of a poor
character.
A second alternative would involve the construction of a dam across the
Millington gorge, 550 feet long and 30 feet high, raising the water to
240 feet above sea level and creating a lake of 14.40 square miles. This
would conserve 4,026,000,000 cubic feet, equal to 2.69 feet on the
drainage area. This would be ample for flood purposes and would still
afford a large impounded area, as the drawing off of an amount equal to
10 or even 15 inches on the watershed would not reduce the size of the
lake to any great extent.
The whole project here presented involves few difficulties, and as the
drainage area above is of small extent, the mere question of conserving
the flood waters could be met without great difficulty. The natural
advantages, however, are so great and the land included within Great
Passaic Swamp is of so little value that the surrounding country would
be improved and beautified by the construction of such a reservoir. The
opportunity for varying the character of the reservoir to meet the ideas
of those interested seems unexampled, and as a whole it presents an
extremely interesting field which may be profitably exploited.
SADDLE RIVER.
This stream has been described in the report on the flood of 1902,
already referred to. It contributes a large amount of water to the main
artery of the Passaic below Dundee dam, and as the river channel at that
point is overburdened under the present conditions because of lack of
slope and numerous catchments, together with what is known as the
Wallington Bend, it increases very materially the damage caused by
floods.
The most effectual remedy in the case of Saddle River floods is that of
construction of flood catchments. No studies have been made of the
situation in the Saddle River drainage area, but a superficial
inspection of the basin shows that opportunities for the construction of
flood-catchment reservoirs are not numerous.
SUMMARY OF FLOOD-CATCHMENT PROJECTS.
By following the plans described in the preceding pages absolute flood
catchments may be provided above Little Falls on the Passaic Basin for
551.7 square miles, leaving only 221.2 square miles from which flood
run-off would flow immediately. The accomplishment of this would involve
the construction of Pompton reservoir, which would withhold all flood
waters from the northern tributaries. It would leave unprovided for 20.2
square miles on the Rockaway, 71.7 square miles on the Whippany, 46.2
square miles on the upper Passaic, and 83.7 square miles tributary to
the Central Basin and not included above.
Leaving Pompton reservoir out of consideration, and conserving flood
run-off on the Ramapo, Wanaque, and Pequanac rivers, there would be
absolute flood catchment up to a 12-inch run-off over 494.8 square miles
above Little Falls. This would leave 278.1 square miles unprovided for,
the run-off from which would not overburden the channel in the lower
valley, provided, of course, that channel were improved to a maximum
carrying capacity.
PREFERABLE RESERVOIR SITES.
The following table and discussion of preferable sites for flood
prevention are taken from the report of the engineering committee of the
northern New Jersey flood commission:
Table showing detailed facts regarding possible reservoir sites on
Passaic drainage basin.
KEY:
A: Area of watershed.
B: Area of reservoir.
C: Height of dam.
D: Length of dam.
E: Elevation of flow line.
F: Storage, watershed.
G: Storage capacity.
H: Total cost.
--------------+-----+------+-----+------+------+-------+-------+---------
Reservoir. | A | B | C | D | E | F | G | H
--------------+-----+------+-----+------+------+-------+-------+---------
| Sq. | Sq. |Feet.| Feet.| Feet.|Inches.|Million|
| mi. | mi. | | | | | c.f. |
Ramapo | 140 | 2.8 | 65 | 1,700| 280 | 5.5 | 1,768 | $900,000
Wanaque | 83 | 2.1 | 60 | 1,200| 275 | 7.7 | 1,491 |1,000,000
Newfoundland | 52 | 1.8 | 40 | 430| 780 | 8 | 966 |1,800,000
Rockaway | 114 | 4.6 | 28 | 470| 520 | 6 | 1,565 | 600,000
Millington | 56 | 15.8 | 25 | 220| 245 | 31 | 4,060 | 370,000
Great Piece | 773 | 37 | 21 | 1,500| 178.5| 9[C]| 8,950 |2,625,000
Mountain View | 380 | 13.4 | 42 | 2,150| 202 | 8 | 7,200 |3,340,000
Do. | 380 | 13.9 | 44 | 2,380| 204 | 9 | 7,900 |3,460,000
Do. | 380 | 14.3 | 46 | 2,470| 206 | 10 | 8,700 |3,590,000
Do. | 380 | 17.4 | 60 | 3,000| 220 | 17 |15,000 |5,260,000
--------------+-----+------+-----+------+------+-------+-------+---------
[Footnote C: Including water discharged through fixed openings,
in a flood similar to that of October, 1903.
Maximum discharge, 12,000 cubic feet per second.]
With the exception of the Millington reservoir site where the cost
of the dam is a small factor, the elevation of flow line in the
various reservoirs which determines the capacity was fixed so as to
afford an approximate storage equal to a run-off of about 8 inches
from the drainage area above each dam site. This amount is somewhat
in excess of the run-off for the flood of October, 1903. It was
found impracticable on the Rockaway reservoir site to provide for a
storage greater than 6 inches. On the Wanaque the amount which can
be stored falls slightly under 8 inches, while on the Ramapo it is
possible to obtain only 5-1/2 inches, by reason of the fact that
with a greater storage capacity the slack water would reach into
New York State. The economical height for a dam at the lower end of
the Great Piece Meadow, if such dam is provided with fixed
discharge openings which will carry a maximum outflow of 12,000
cubic feet per second, will provide a reservoir which will dispose
of a run-off of 9 inches on the drainage area above.
The following combinations of reservoir sites, with their
respective drainage areas, proportional storage, and estimated
costs, give the facts necessary for final deductions:
--------------+---------------+-----------+---------------+-----------
| Drainage | Water | Equivalent |
Site. | area. |collected. | area | Cost.
| | | retarded. |
--------------+---------------+-----------+---------------+-----------
|_Square miles._| _Inches._ |_Square miles._|
Ramapo | 140 | 5.5 | 96.25 | $900,000
Wanaque | 83 | 7.7 | 80 | 1,000,000
Pequanac | 52 | 8 | 52 | 1,800,000
Rockaway | 114 | 6 | 85.5 | 600,000
|---------------+-----------+----------------+----------
Total | 389 | | 313.75 | 4,300,000
|=======================================================
Ramapo | 140 | 5.5 | 96.25 | 900,000
Wanaque | 83 | 7.7 | 80 | 1,000,000
Rockaway | 114 | 6 | 85.5 | 600,000
Millington | 56 | 31 | 56 | 370,000
Total | 393 | | 317.75 | 3,870,000
|=======================================================
Great Piece | 773 | 4.5 | 435 | 2,625,000
Mountain View | 380 | 8 | 380 | 3,340,000
--------------+---------------+-----------+---------------+-----------
The necessity to retard the flow of or provide storage for
approximately 380 square miles of highland drainage area has been
determined after careful study, and there has been deduced an
amount which may safely be expected to represent the maximum for
the highest floods. When the highland tributaries are sufficiently
checked the natural storage on Great Piece Meadow in its effect
upon flood control becomes more apparent. Our investigations show
that the holding back of the flood flow--that is, 8 inches run-off
on approximately 380 square miles of flashy drainage area above
Great Piece Meadow--is necessary to reduce the discharge in the
river through the city of Paterson to 14,000 cubic feet per second
for a flood similar to that of 1903.
From the foregoing table, in which different reservoir projects are
compared, it is seen that only the reservoirs designated as Great
Piece and Mountain View will fulfill the requirements within a
reasonable limit of cost. It is also shown that a combination of
any other available sites would involve the expenditure of more
money for their construction and the control of less tributary
drainage area than is fulfilled by the demands of the Passaic
drainage basin. We are therefore brought to the conclusion that
only two of the projects above set forth will be effective. First,
the construction of a regulating dam on the main stream above
Little Falls, which we have called the "Great Piece" Meadow
Reservoir, and second, the building of a dam at Mountain View
across Pompton River. The relative cost of these reservoirs,
constructed for flood control exclusively, is $2,625,000 for that
on Great Piece Meadow and $3,340,000 for the Mountain View site.
Details of these estimates are as follows:
_Estimate of cost of Great Piece Reservoir, dam at Little Falls._
[Elevation of flow line, 178.5 feet. Storage and disposal of 9 inches
collected.[D]]
Earth excavation, 17,600 cubic yards, at 35 cents $6,160
Rock excavation, 8,800 cubic yards, at $2 17,600
Rubble masonry, 29,100 cubic yards, at $5 145,500
Ashlar masonry, 1,800 cubic yards, at $12 21,600
Facework of rubble masonry, 2,850 square yards, at $1.50 4,275
Concrete masonry, 250 cubic yards, at $6 1,500
Slope paving, 300 cubic yards, at $2 600
Crushed stone, 150 cubic yards, at $1.50 225
60-inch cast-iron pipe in place, 360 tons, at $35 12,600
Relocation of railroads, Erie, 5 miles, at $20,000;
Delaware, Lackawanna and Western, 4.5 miles, at $40,000 280,000
Relocation of highways 170,000
Real estate:
Above Mountain View 500,000
Additional for village of Singac 100,000
22,000 acres, at $50 1,100,000
----------
2,360,000
Add for engineering and contingencies 240,000
----------
2,600,000
Protection of pipe lines, Newark and Jersey City 25,000
----------
2,625,000
The effectiveness of a reservoir built upon the lines proposed in
the case of Great Piece Meadow depends upon the adjustment of
outflow so that the channel below will not be overborne, while at
the same time sufficient storage capacity is afforded to hold
temporarily the water which enters above the dam in amount greater
than the carrying capacity of the outflow apertures. The dam across
Passaic River above Little Falls would be provided with apertures
which would discharge 12,000 cubic feet per second under the
maximum head in the storage basin. As the flood rises these
apertures would discharge a constantly increasing amount of water
to the maximum, and for a considerable time thereafter the maximum
would be maintained, the discharge decreasing after the flood
according to the height of water remaining in the reservoir.
[Footnote D: Includes water discharged through fixed openings for a
flood similar to that of October, 1903. Maximum flow, 12,000 cubic feet
per second.]
_Estimated cost of Mountain View Reservoir._
[Elevation of flow line, 202 feet. Storage of 8 inches on watershed.]
Earth excavation:
Stripping dam base, 83,500 cubic yards, at $0.30 $25,050
Core wall trench, 24,900 cubic yards, at $1 24,900
Rock excavation, 10,100 cubic yards, at $2 20,200
Rock fill in dam, 197,000 cubic yards, at $1.25 246,250
Rubble masonry, 23,200 cubic yards, at $5 116,000
Concrete, 30,000 cubic yards, at $6 180,000
Gate chambers and tunnels 65,000
Reconstruction of highways 142,400
Reconstruction of railroads 815,000
Real estate 1,360,000
----------
2,994,800
Engineering and contingencies 325,200
----------
3,320,000
Protection of Newark pipe line 20,000
----------
Total cost 3,340,000
[Same for elevation of flow line, 204 feet. Storage of 9 inches on
watershed.]
Earth excavation:
Stripping dam base, 85,200 cubic yards, at $0.30 $25,560
Core wall trench, 26,000 cubic yards, at $1 26,000
Rock excavation, 10,600 cubic yards, at $2 21,200
Rock fill in dam, 214,000 cubic yards, at $1.25 267,500
Rubble masonry, 24,500 cubic yards, at $5 122,500
Concrete, 30,500 cubic yards, at $6 183,000
Gate chambers and tunnels 65,000
Reconstruction of highways 142,400
Reconstruction of railroads 815,000
Real estate 1,435,000
----------
3,103,160
Engineering and contingencies 336,840
----------
3,440,000
Protection of Newark pipe line 20,000
----------
Total cost 3,460,000
The final recommendation of the committee involves the
consideration of two projects for flood storage, one on Great Piece
Meadow and the other above Mountain View on the Pompton. In making
such recommendations the committee is of the opinion that it must
take into account matters of engineering policy with regard to
future needs and contingencies, as well as the bare necessities of
the present.
If there were none other than the single problem of prevention the
committee would advise the construction of the reservoir on Great
Piece Meadow by reason of its smaller probable cost and its equal
efficiency. It is plain, however, that there are many important
features of public policy involved in the subject at hand.
Population in the valley of the Passaic is developing so rapidly
that in only a few years the present sources of water supply will
be inadequate. The whole subject of water supply for northern New
Jersey demands immediate consideration, and it would not be wise to
take up the matter of prevention of flood damage in the Passaic
without basing the value of every project upon its adaptability
for use in future water-supply needs.
By expending $2,600,000 a great reservoir could be constructed upon
Great Piece Meadow which could not be adapted for any purposes
except to regulate floods; it would stand in season and out of
season a huge feature of the valley and entirely useless and
inoperative save on the occasion of high water. However great might
be the needs of the inhabitants of the Passaic Valley for a
conserved water supply, the construction on the meadows,
representing an enormous expenditure, would furnish no solution of
the problem. It would admit of no enlargement for water-supply
storage and would be available for no purpose except flood
regulation.
When we consider the Mountain View project, however, we find that
as a measure for the prevention of flood damages it fulfills all
the requirements and provides in addition all the possibilities and
advantages demanded inevitably in the near future. The Mountain
View site is an ideal one for the reservoir, and its initial
development for flood catchment does not involve the expenditure of
a dollar that would be lost in the development of the basin to
greater capacities for water supply. From its lowest level, at 202
feet above tide, to its maximum capacity, at a level of 220, there
would be no depreciation. Every dollar spent in the initial
construction would be effective in the maximum development.
The probable cost of Mountain View reservoir, estimated at
$3,340,000, exceeds that of Great Piece by $700,000. It is realized
that to many persons this margin may seem very wide. Let us
consider briefly just what it really represents.