If the drainage system used is the lateral trench, then the calculation of distance and depth should be considered. For collectors, trench spacing is determined by the size of the land or the maximum length of the drainage pipe. On flat land with a singular system of drainage pipes, trench spacing is usually between 200-500 m. Water level in the trench collectors must be maintained at a depth below the drain holes of the drainage pipe (lateral).
Calculating the dimensions of the trenches following the channel design is not plated by knowing parameters such as, (1) the desired water level, (2) the discharge capacity, and (3) the type of soil. Sometimes calculating the dimensions of the trench produces a dimension that is too small, so in terms of construction and maintenance difficult to do.
A. Type Channels
Drainage canals are generally open or closed. But should the channel open only to drain waste water is relatively odorless, like rain or surface water (seepage irrigation systems, springs, etc.). While the closed channel used to drain waste water from the shower, WC, kitchen, laundry or effluent result of industrial processes.
The cross-Channel B.
There is a wide range of channel cross sections are used, but in open channel widely used channels berpenampang rectangular and trapezoidal. For the cross section of the channel is closed, widely used pipeline berpenampang round.
1) Forms Penampang Open Channels
2) There are several types of open channel cross-sectional shape that is normally used in the manufacture of drainage channels, among others:
a. Segi Channel Four
Figure 32. Channel Four Aspects
b. Segi channel with Channel Four Small
Figure 33. Channels with Channel Four Segi Small
c. Trapezoid channels
Figure 34. Trapezoid Channel
d. Trapezoid Channels With Small Channels
Figure 35. Trapezoid Channels with Small Channels