Experimental study of hydraulic characteristics of water diversion from the river bed with cutoff wall

In arid and semi-arid regions, sub-surface flow of a river can be a potential of water supply.. Different methods have already been used to divert surface and subsurface water in the rivers. In this research, an experimental model of the intake was built in Hydraulic Laboratory in Water Engineering Department of Ferdowsi University for diverting surface and subsurface flow from the river and the effective factors on the amount of diverted flow were investigated. Results showed a direct relationship between the flow rate and the water level above each drain and the drained flow rate increases with increasing distance between the drains. The discharge of drains varies along the porous media, as it decreases at first and then increases. The lowest discharge was belong to middle drain. The assessment of different drains arrangement indicated that the installation of two rows of the drains in two depths gives higher efficiency. Finally, a regression mathematical model was developed for designing the subsurface intake with porous medium and drainage system.