Figure 1
Bittit irrigation system, including the Seguia Khrichfa (secondary canal).
Figure 2
Side view of an orifice. The discharge passing through the orifice is a function of the height of the water above the downstream water height (h).
Figure 3
When an additional orifice is opened, the water height will lower (dotted lines), thus resulting in a lower discharge through each orifice.
Figure 4
Use of the T.O.R. gates to obtain a proportional water division (starting in the upper-left corner, clockwise): 1) offtake of a water user who does not irrigate; 2) offtake of the most upstream irrigating water user; 3) offtake of the second irrigating water user; 4) offtake of the most downstream irrigating water user.
Figure 5
The exchanges of water at the Khrichfa canal: water user 1 irrigates with half of his irrigation hours, then gives the remaining water to water user 8. After irrigating, water user 8 gives the water turn to the downstream neighbour of water user 1, thus water user 2.