Frequently Asked Questions
Yes, docks are permitted to be dredged on reservoirs and lakes. However, each lake’s manager or owner has requirements of how and when a dock can be dredged. The US Army Corps of Engineers, Georgia Power, and TVA differ in requirements and dredging permits from each lake.
Yes, dredging can be performed with the water at full pool or below full pool. Dredging can be done from the shoreline or with the use of a barge.
Small hand operated dredges can be purchased for as little as $15,000, but they are only effective for limited types of projects and sediment. The smaller dredge barges can be purchased for $100,000 to $150,000. As you increase in size and effectiveness, most portable dredges cost between $500,000 and $2,000,000. The cost only increases for dredges bigger and with more features extending through the millions and for the largest dredges into the tens of millions. Auxiliary equipment and pipeline are an additional expense that needs to be considered as well in the cost of purchasing a dredge.
Dredging is highly variable in cost. Cost involved for dredging projects are typically as follows:
- Permitting – local, state, and federal are considered in most projects
- Planning – designing engineered plans usually for the dewatering area and disposal
- Mobilization – both of the equipment, the setup for dewatering, and disposal site
- Depth of Sediment – water and sediment depth determine much of the cost involved (i.e. shallow sediment depth takes much more time to dredge)
- Type of Sediment – texture of the sediment determines the type of dredge and dewatering process; debris can add to cost significantly
- Run-times – 24/7 or 5 days for 8 hours; weather is also a major factor depending on the project
- Export and Transport – the time for the dewatering (immediate vs. months) and distance to the disposal area
- Disposal – the setup of the disposal area and final reclamation; or the tip-fee for a landfill
- Remediation – clean-up of the project site and installation of best management practices
Costs to operate the dredge include wear parts, labor, fuel, and maintenance. Dredges are unique in that break-downs and maintenance usually have to occur on the water so adequate support personnel and equipment must be available. All of these factors is why dredging cost range from a $3 to $300 per cubic yard. Dredging is often limited by other factors such as dewatering or disposal, so costs can be affected by the entire process as well.
Many water treatment plants are designed to store raw water within a reservoir prior to treatment. If your reservoir is losing capacity as a result of sedimentation, dredging may be the best solution. Dredging can remove the sediment without lowering the water level, and use of NSF polymers ensure that drinking water supply continues safely. Hydraulic dredging is a preferred method to dredge the sediment while the water remains in the reservoir.
Algae can be expensive to treat and remove from drinking water. It can even be deadly. During summer months algae blooms in raw water reservoirs can be a concern. Treating the lake with alum treatments is one way to reduce the available Phosphorus within the water. However, dredging is another method that actually removes phosphorus that is attached to the sediment. Dredging can improve water quality be removing excessive phosphorus and sediment, reducing treatment costs for algae and turbidity. Dredging can also increase storage capacity and decrease drought conditions.
Dredging is the only practical solution for removing accumulated sediment from reservoirs. Large reservoirs cannot be flushed and sediment does not disappear on its on. Over time sediment in reservoirs causes loss of storage capacity, diminishing recreational opportunities, decreased aquatic habitat, poor water quality (leading to eutrophication), and loss of property values. Dredging can help solve the issues related to sedimentation.