An investigation was carried out to evaluate the effect of improving the velocity in front
of intakes to control the effect of sedimentation on withdrawal water turbidity. The
phenomenon of sedimentation is one of the most important problems affecting intakes
of water treatment plants. The Nile river is known to be an alluvial river, so pipe intakes
are the most affected by sedimentation due to its contribution as an obstacle on the river
side which lead to the reduction of water velocity on its side which leads to increase the
deposition rate at the intake. On the other hand, any regulation work may be work on
increasing the water velocity at the intake site, causes increasing of water turbidity and
will lead to increasing of the treatment cost. A comparison between different methods of
regulation works such as dredging; spur dike usage on the other side of the intake, and
the removal of flow obstructions was carried out to adjust the velocity to reach a proper
value. Experimental results indicated that the dredging upstream the pipe intake 50m to
200m downstream the pipe intake with a width of 100 m is a sustainable alternative in
economic terms for sediment control. On the other hand using spur dikes as a second
sustainable alternative may be desirable in terms of initial cost and river morphological
stabilization. |
