Harbor Dredging Permitting
Historical Low Great Lakes Levels fOrce Dredging
Great Lakes Levels
The water level of Lakes Michigan and Huron have fallen to their lowest levels since the United States Army Corps of Engineers (USACE) began recording data in 1918. As shown in the chart below, the levels now match the historical lows in the 1960s and are about 5 feet lower than the levels from the mid-1980s.
The low lake levels are causing problems for nearly all marinas and around the Great Lakes. Many harbors have lost docking space and water levels have limited the use of some boat launch ramps.
To keep harbors functional for the boating community, many facilities on the Great Lakes are planning to dredge to meet the demand for docking space. In some instances, dredging will be required to meet lease agreements that facilities have with boat owners.
Facility owners and operators must first permit dredging activities. Dredging the bottom lands of the Great Lakes requires a joint permit from the MDEQ and the USACE. Many facility operators are familiar with maintenance dredging and may already have permits in place for annual dredging. But, the lower lake levels require dredging to depths not anticipated, or dredging in new areas that are not covered by a maintenance permit.
Dredging Permitting Process
The permitting process for dredging can typically take 90 days and requires the applicant to complete the following steps:
- Define the area to be dredged and prepare a bottomlands survey.
- Develop cross sections showing the dredging depth and calculate the volume that will be removed.
- Sample and test the bottom material that will be dredged. A minimum of 6 samples must be obtained if the dredging volume is less than 10,000 cubic yards. The sampling requirement may be waived if the dredge volume is less than 1,000 cubic yards.
- Perform a sieve analysis in a soils laboratory to determine if the bottom material is sand. If it is sand, no additional testing is required.
- If the bottom material is not classified as sand, then the soil samples must be tested for chemicals such as metals, PCBs and PNAs.
- If lab testing indicates that the bottom material contains less than the State’s prescribed limits for these compounds, then no additional testing is required.
- However, if metals in the materials that will be dredged exceed State limits, then the material must be tested for toxic and other compounds that could leach from the dredged materials (TCLP and SPLP testing). These tests will determine if the dredged materials can be safely deposited at an upland site of if they need to be deposited at a licensed landfill.
- After the test results are available, the permit application will be submitted to the MDEQ-USACE and the proposed dredging project will be public noticed. The cost of the permit fee depends on the volume that will be dredged.
- The permit application must designate suitable upland disposal site(s) for the dredged material. If the material is sand, it can be used for beach nourishment.
Tips for Controlling Cost
Dredging can be a very expensive activity. Some of the techniques that facility owners can use to help control costs include:
- Identify disposal sites that can be conveniently accessed by large trucks and heavy equipment and that minimize the haul distance from the harbor.
- If possible, configure the dredging activity from land-based operations rather than the more expensive water-based (barge) operations.
- Provide convenient access to the dredging area for heavy equipment and provide nearby staging areas for equipment.
- Conduct before and after hydrographic surveys using GPS survey techniques to accurately determine dredge volumes.