Sedimentation in reservoirs: Investigating reservoir preservation options and the possibility of implementing Water Injection Dredging in reservoirs

Sedimentation in reservoirs: Investigating reservoir preservation options and the possibility of implementing Water Injection Dredging in reservoirs

Bronsvoort, K.

Van Rhee, C. (mentor)
Keetels, G.H. (mentor)
Laboyrie, H.P. (mentor)
Sloff, C.J. (mentor)

Civil Engineering and Geosciences

Hydraulic Engineering

Dredging Engineering

2013-02-07

Sedimentation in reservoirs is a consequence of constructing a barrier in a flowing river, which results in a decrease of the transport capacity of the river. The storage capacity of the reservoir decreases due to the accumulation of sediments and the river downstream starts to erode due to the disturbance of the sediment balance. Water Injection Dredging can be an interesting option in order to counteract these processes. This method injects water in the bottom of the reservoir, creating hereby density currents which are capable of transporting large amounts of sediment. The sediment can in this way be transported towards the dead storage of the reservoir or be sluiced out of the reservoir through the bottom outlets of a dam, which will increase the storage capacity of a reservoir considerably. Because the density current uses gravitation and the natural slope of the reservoir, this method is a relative cheap and quick way to transport sediments. The dredging installation is also relatively simple and basic. If the sediments are sluiced through the dam, the disturbance of the sediment balance in the river can be counteracted. It is however necessary to investigate whether or not the river is capable of dealing with the increased sediment load in the river downstream of the dam. The high production rates of Water Injection Dredging results in high sediments peaks, which the river should be able to transport. Case studies done in the scope of this thesis show that the method can be a competitive and feasible method that can be used to counteract sedimentation problems in reservoirs, if some specifications of the investigated reservoirs were different. If these specific requirements for Water Injection Dredging in reservoir are met, the method can restore the reservoir capacity in a cheap and effective way. More research and testing the method in practice will be necessary however.

reservoir
sedimentation
Water Injection Dredging

http://resolver.tudelft.nl/uuid:191323c1-b2ec-4d3e-9e28-2958c1ee287c

2013-04-30

Student theses

master thesis

(c) 2013 Bronsvoort, K.