The ongoing demands of an ever-growing population call for the continuous alteration of inland waters, and the building of dams and reservoirs for numerous reasons, such as power generation or prevention of flooding. However, all dams, reservoirs and hydropower plants inevitably face the problem of sedimentation.
As sediment accumulates in a reservoir, the dam gradually loses its ability to store water, impacting the purpose for which it was built. This leads to clogging, a disruption of the sediment balance, loss of capacity and eventually to the reservoir falling into inactivity. For hydro dams, the flow towards the turbines can become increasingly polluted and disrupted, resulting in increased maintenance and decreased energy production.
Despite decades of research, sedimentation is still probably the most serious technical problem faced by the dam industry.
The optimal solution
So, what is to be done? Some sediment management strategies can be implemented, but they are often impractical. In addition, raising the dam or building entirely new facilities is often counterproductive. An alternative option is to remove the sediment from the reservoir by dredging. This helps to increase the water storage volume, enhance the water quality and remove contaminated material.
Choosing the most effective dredging equipment will improve the performance of the dam and the reservoir. However, any dredging solution must be transported and mobilised in remote or mountainous regions.
Effective dredging equipment
Dismountable cutter suction dredgers (CSDs) have been developed for dredging in remote and poorly accessible reservoirs. They are easy to transport by road or air, and suitable for the majority of dredging operations. CSDs can dredge to a significant depth (up to 50 metres), and handle most soil types.
With many reservoirs ageing, sedimentation will become more of a challenge. Using the right dredging equipment will keep production levels up and costs down. As such, CSDs have been designed for the conditions specific for dredging reservoirs, and are frequently used for these operations.