9460

• UCREFRP Catalog Number: 9460
• Author: Wentz, W. A.
• Title: Wetlands Values and Management.
• USFW Year: 1981.
• USFW - Doc Type: Washington, D.C.
• Copyright Material: NO

Dredging, Diking, and Ditching

Dredging and diking are usually necessary
in order to create new wetlands or to
begin controlling the water levels in an
existing wetland. This technique is usually
expensive, but it is also usually the only
reasonable method for gaining control of
water levels. In some instances a marsh
may have limited inflow or outflow chan-
nels and it will be possible to use a very
limited amount of diking to control the
entire wetland. In extensive marsh sys-
tems a large amount of diking will be
necessary. In some cases a very low dike
can be created with readily available farm
implements.
Carefully planned diking may be used
to create a new marsh by flooding former
upland or it may be used to expand the
size of an existing marsh. Diking com-
bined with water level control will allow
the creation of the most favorable and
productive marsh.
Blasting has sometimes been used to
create ditch systems, but this method
leaves spoil banks that are very suscepti-
ble to wind and wave erosion. Dragline

ditching leaves spoil banks that, when
properly deposited, leave a chain of
islands that serve as nesting sites for
waterfowl, den sites for muskrats, and
habitat for a wide variety of other marsh
animals.
Level ditching is a method of creating
open water and a series of islands in large
marshes. Draglines or bulldozers may be
used for this purpose. The dredging
increases habitat variety by providing
open water and dry areas for nesting and
den sites. Level ditching has been shown
to increase furbearer and waterfowl pro-
duction significantly on some marshes.
The ditch systems also allow boat access
to the marsh during hunting and trapping
seasons. Level ditching is useful primarily
on very large marsh systems. In small
marshes the technique may result in irrep-
arable damage to the wetland ecosystem.
This technique is fairly expensive and it
should not be undertaken without sound
guidance from professional biologists and
engineers. The use of this technique will
require various state or federal permits.

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