Seepage from Trapezoidal Channels

No solution for the problem of seepage from trapezoidal channels in homogeneous and isotropic material with drainages at a finite distance from the canal and at a finite depth is available so far. This general problem is solved exactly by the use of conformal mapping. Equations for seepage discharge and the shape of the free surface are given. These equations are solved numerically. The results are given in the form of easy-to-use curves. The analysis indicates that the phreatic surface has a continuous curve from the canal to the drain. This surface rises with increase in bed width, water depth and drainage distance, though the effect of side slopes is very little. The seepage discharge increases with an increase in bed width, water depth, side slopes, and with a decrease in the drainage distance.