Selection of suitable site for the canal falls
- For main and branch canals, which do not directly irrigate the fields, the site is determined on the basis of economy in earth works. The excavated earth is used to make banks. This depth of excavation is known as balancing depth of excavation. Suitable site for canal falls will be where the depth of excavation becomes less than the balancing depth.
- For the Distributory and minor canals, falls may be located downstream of the outlets as this help in increasing the command area, and in improving the efficiency of outlets.
- Site should be selected keeping in mind the requirements for a road crossing, as a bridge combined with a fall offers an economical structure.
- A regulator may be combined with a fall downstream of the off-taking channel. It has been done in Bombanwala head works on upper chenab canal. At this site, BRBD canal and Rayya branch canal take off in Punjab Pakistan.