Dredging Impacts Study
Bay-Lake Regional Planning Commission
Basin Program Funds:
Each year thousands of cubic yards of silt and sediments are dredged from the
many small commercial harbor and marina facilities located within the Wisconsin
Bay-Lake region. It appears that the need to dredge is perpetual and that the
environmental and economic costs of dredging are enormous.
The Wisconsin Bay-Lake region contains approximately 450 miles of shoreline,
encompasses three designated Areas of Concern (Marinette, Green Bay, and Sheboygan),
and includes 185 units of local government. A majority of these governmental
units are located in watersheds that drain to Green Bay or Lake Michigan. Dredging
has become a major issue in the region, as increasing amounts of sediment are
transported through these watersheds and deposited into the many harbors and
marina facilities located in the Bay-Lake region.
This study assessed the extent and cost of maintenance dredging of the more
than 70 harbors and marinas in the Bay-Lake region, and the impact of these
costs on the communities. The cost assessment developed data that was used to
determine the economic impact of dredging. These data may, in turn, be applied
as a basis to influence public opinion and policy regarding the need to enact
and enforce comprehensive soil erosion and sedimentation controls, as well as
the implement best management practices (BMPs) that will reduce the frequency
and need for dredging.
The Bay-Lake Regional Planning Commission undertook an inventory
of dredging activities within the Commission's coastal areas. The inventory
included all dredging permits that had been issued within the study area by
the Wisconsin Department of Natural Resources and the U.S. Army Corps of Engineers.
The inventory was used to create a database containing information on dredging
material and dredging costs. The material component of the database included
a characterization of the materials dredged, quantification of the amount dredged
and frequency of dredging, and a review of disposal options. The cost component
included the engineering costs, permit and enforcement costs, dredging costs,
and disposal costs. Investigators created a database using existing data on
current and historic dredging activities in the region.
After the database was completed, investigators undertook an economic impact
study. Data relative to the cost of upland streambank protection and policy
and planning development, both general in scope and specific to the watersheds
located within the Bay-Lake region, was compiled and analyzed. The cost to enact
and enforce comprehensive soil erosion and sediment controls, and to implement
best management practices was determined. The direct and indirect economic benefits
of harbor facilities -- the Manitowoc and Kewaumee harbors -- was determined
and analyzed by utilizing past planning documents.
The Bay-Lake Regional Planning Commission completed An Inventory & Assessment
of Dredging in the Bay-Lake Region, which was distributed to the Technical Review
Committee of the Bay-Lake Regional Harbor Council. The information will also
be disseminated through newsletter articles and reports to appropriate regional
commissions and committees.
Contact: Martin W. Holden, (920) 448-2820