You may have heard of a naturally occurring process called sedimentation, which is the accumulation of silt, sand and other debris on the bottom of a river, lake, canal or stream over time. An excessive build-up of sediment can cause a series of issues. For instance, it can reduce the depth of the waterway and prevent the passage of ships. It can also lead to contamination that poses a threat to aquatic plant and wildlife. In coastal areas, sediment accumulation can cause beaches to erode.
What Is Dredging?
It often becomes necessary to find a way to remove a large accumulation of sediment to preserve the health of the waterway and enable its continued use for commercial applications. A process known as dredging can provide a fast, efficient sediment removal solution.
Dredging is essentially an excavation technique that makes use of specially designed equipment to “vacuum” silt and debris from the bottom of a waterway. Dredging can clean, widen and deepen a body of water, and even help to reverse the harmful impact of erosion.
Why Would You Use Dredging?
Dredging is useful for many applications. Some of the reasons why you would use dredging include:
- Create waterways: Many ports are building new waterways with dredging to reach new trade centers and improve the efficiency of the transport of goods. Dredging ensures cargo vessels of all sizes can dock and do not run aground. They’re also useful for waterway projects involving underwater tunnels, bridges, piers and more.
- Re-open channels: Sediment builds up over time, which can make harbors and piers dangerous for ships. But with dredging, you can clear the built-up sediment and restore the waterway to its original depth, allowing tankers and other vessels to dock safely. Dredging also removes dead vegetation, pollutants and trash that may have gathered in these areas.
- Restore shorelines: Another reason why you would dredge is due to soil erosion. Beachfront areas often erode due to hurricanes, which can change their landscape and impact their local ecosystem. Dredging reverses the effects of soil erosion, keeping the local ecosystem and its native plant and aquatic wildlife intact.
- Maintain ecosystems: Dredging helps ecosystems in a variety of ways. By removing trash, sludge, dead vegetation and other debris, it keeps them clean and preserves the local wildlife. It also remediates eutrophication, which is an excess of nutrients in the water due to runoff. By solving eutrophication, you stop the excess growth of plant life, which can cause oxygen deprivation.
The Sediment Removal Process
How does dredging work? A dredge, the machine used to execute the sediment removal process, is equipped with a powerful submersible pump that relies on suction to excavate the debris. A long tube carries the sediment from the bottom to the surface. The disposal of the dredged material must be conducted in compliance with federal, state and local government laws and regulations.
What Are the Various Types of Dredges?
There are several types of dredges used in the sediment removal process:
- Plain-Suction: A plain-suction dredge is the most common type of sediment removal equipment. Unlike other dredge versions, it doesn’t contain a tool for penetrating or cutting into the bottom of the water body — it relies on suction to remove loose debris.
- Cutter-Suction: This type of dredge contains a cutting tool that loosens material from the bottom and transports it to the mouth of the suction apparatus. The use of a cutter-suction dredge may be necessary for removing debris from hard surfaces that would prevent efficient suction via standard methods.
- Auger-Suction: An auger-suction dredge essentially bores holes into the bed to loosen and suck up the debris. The rotating auger can burrow deeply into the surface. This type of dredge works well for sludge removal applications at wastewater treatment plants and other areas requiring heavy-duty sediment removal.
- Jet-Lift: This technologically advanced sediment removal equipment works by injecting a high-volume stream of water to pull in nearby water, silt and debris.
GeoForm International offers high-quality sediment removal equipment that can handle your most challenging dredging applications. Our dredges, the Dino6 dredge, and the Dino8 dredge are used around the world for sediment removal processes. Contact us for more information today.