What types of dredging projects exist?

  • Maintenance: Regularly scheduled to remove silt/sediment from navigation channels.
  • Developmental: Creating new berths, ports, or deepening existing ones.
  • Environmental: Removing contaminated sediments to improve ecosystem health.
  • Emergency: Rapid response to sudden shoaling from storms or accidents.

How does a dredge work?

  • Cutter-suction: Uses a rotating cutter head to loosen material, which is then pumped through a pipe.
  • Plain-suction: Relies on suction to remove loose debris, ideal for sand.
  • Bucket/Clamshell: Scoops sediment and lifts it to a barge, suitable for hard materials or precise excavation.

How is the dredged material managed?

  • It is often moved to a confined disposal facility (CDF) to dewater. It can be used for beach nourishment, land creation, or, if clean, environmental restoration.

What are the key permitting requirements?

  • In the U.S., projects require permits from the US Army Corps of Engineers (Section 404) and environmental approval from state agencies (e.g., CT DEEP).

What factors affect cost?

  • Volume: The total cubic yards to be removed.
  • Material: Silt/sand is cheaper than rock.
  • Disposal Distance: Trucking spoil away is the highest cost factor.

Do I need to drain my pond or lake to dredge it?

  • No. Hydraulic dredges can work while the pond is full.