Improve continuity of sediment transport

Improve continuity of sediment transport

Category 02. Sediment flow quantity improvement

Expected effect of measure on (including literature citations):

• HYMO (general and specified per HYMO element)
• physico � chemical parameters
• Biota (general and specified per Biological quality elements)

Pressures that can be addressed by this measure

• Reservoir flushing
• Sediment discharge from dredging
• Colinear connected reservoir
• Sand and gravel extraction
• Artificial barriers upstream from the site
• Artificial barriers downstream from the site
• Impoundment
• Sedimentation and sediment input

Case studies where this measure has been applied

Continuous Sediment transfer is successfully being applied e.g. at Olsberg Reservoir of operator RWE since 2011. An automated vessel provides year round sediment transfer, except during ice coverage. Over time the vessel strikes the complete reservoir ground to transfer incoming sediment which deposited on the reservoirs floor. The sucked sediment is pumped to the aligned hydro power plant where the sediment is dropped in front of the turbine inlet and transferred through the turbine to the downstream river. The turbine ensures a good mixing with the outflow. Turbine components are not affected at the given sediment ratio.

A scaling instrument aboard the vessel allows for automatically adjusting a sediment transfer volume which suits to the actual plant/reservoir outflow and downstream compatibility. Transfer capacity at this application is up to 20 t/day, depending on the reservoirs outflow. The downstream river as well as the reservoir itself experienced a significant increase in ecological condition assessment within only weeks.

Automated Sediment Transfer Vessel (photo courtesy of DB Sediments).

• Inchewan Burn Bed Restoration
• Sella
• Narew river restoration project