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he requirement to dredge our navigable waterways to in-
Thus, the viability of our economy is clearly dependent
sure proper. channel depths for shipping, and the resul-
upon our ability to keep the channels of our waterways,
tant need to dispose of the dredged materials, has become a
ports, and harbors open to navigation. However, our harbors
problem of great national significance. Unless we can find
and channels are subject to shoaling and loss of depth from
ways to continue the maintenance of our waterways in the
natural deposits of material. In order to maintain navigation
face of environmental, legal and technical constraints, a
we either have to limit vessel draft or remove the material
situation may be precipitated which could adversely affect
blocking the channels by dredging.
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the entire economy.
For the past 30 years, domestic waterborne commerce, in-
his national decision involves the Corps for the following
cluding inland barge and Great Lakes traffic, has moved
reason. Since 1824, the Corps has had a congressionally
almost 16 percent of the Nation's ton-miles of intercity
mandated mission to plan, construct, operate and maintain
cargo.
our waterways. During this time, the country has developed
This inland waterway barge traffic has increased over the
25,000 miles of navigable channels, 107 commercial ports
past 2 decades at a compound rate of slightly over 5 percent
and harbors and 400 small boat harbors. Fifteen thousand
per year.
miles of these channels are 9 feet or more in depth and, ex-
cept for the upper Mississippi and Missouri Rivers and the
St. Lawrence Seaway, all of the waterways are open to year-
The amount of tonnage that can be moved in a single
round navigation.
tow has increased from 5,000 to 50,000 tons per tow
In order to maintain this year-round capability, periodic
during that period. It is predicted that traffic on
dredging of all channels is required. This, by itself, is a
various segments of the waterways will increase from
straightforward task, varied only by the methodology in-
4 to 6 times in the next 50 years. Total waterway com-
volved, and for 150 years dredging has been a daily activity
merce presently totals 1.7 billion tons per year-over
attracting little or no attention from the public or other water
350 billion ton-miles-or about 7 tons per capita. This
resource agencies. All of a sudden, however, dredging
cargo is carried at an average cost of 3 mils per ton-
became a dirty word and the Corps was placed in the position
mile.
of being able to take the material from the bottom of our
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waterway channels-but without any place to put it.
. While the freight traffic of grain, ores, chemicals and con-
structi.on ma.terials con.tinues to increase it is the energyh-
When constraints are placed on the methods of disposal of
the dredged material, a classic dilemma is born. Dredging is
producing commodities, predominantly petroleum and coal,
essential or shipping stops. If there is no place to put the
that comprise slightly over 50 percent of the domestic water-
transient real estate blocking the channel-we cannot
borne freight. As the cost of energy materials increases, it
dredge. We found the sharp horns of this dilemma gouging
becomes more important to move them as economically as
us more deeply each day.
possible for the ultimate benefit of the American consumer.
So the stage was set for the entrance of the first con-
As the prime mover of energy supplies, water carriers are also
straint-the environment! Previously, there has been very
the least consumptive-using less than 500 British Thermal
little understanding of the national dredging program on the
Units of energy per ton-mile.
part of either the general public or other water resource
About 1/3 of total waterway commerce is with foreign
agencies. Nor has there been any attempt on the part of the
countries. Raw materials and manufactured products which
Corps to explain what essentially was a routine operation.
move through our waterway system to the export market
Consequently, when the environmental alarm bells rang and
contribute significantly to our national economic health by
`pollution" became a household word, it was understanda-
bulwarking our balance of payment deficit and helping to
ble that concern would b evidenced when there was talk of
e
keep the dollar strong in foreign markets.
wetlands being destroyed by dredged material placement,
While a national view of waterway economic statistics may
back channels being blocked to the detriment of fish and
demonstrate magnitude, a narrower focus can be more
wildlife, and deep water areas used for placement of dredged
meaningful when applied to a localized situation. At New
material named "ocean wastelands."
Orleans, for example, the economic impact of the port to the
local area and to the State is tremendous. The chain of eco-
ter public understanding of the problem, it is essential t o
nomic events that starts when cargo lands at that port finally
discuss openly and fully the pros and cons of the dredged
results in the employment of 37,000 people, million in
material placement program, the constraints under which
city taxes, million in State taxes, 6 million in port-
the Corps operates, and what is being done to rectify the
related income. and a total economic impact on Louisiana of
situation.
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.8 billion a year.
here are only 4 general types of areas that may e used for
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placement of the material removed from the channels,
These are off-channel, ocean or other open water areas,
diked areas, or areas upland from the dredging site. Each has
both advantages and disadvantages.
Off-channel discharge, common to our inland waterways,
is highly cost effective. This consists merely of a dredge
pumping the material from the bottom of the channel and
redepositing it in the water far enough away from the pickup
point to prevent the material from slipping back into the
channel. This method has some positive benefits, in that it
can extend wetland areas, create artificial islands and
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