Economics of Detour Canal Alignments

In major irrigation projects, the main canals are generally aligned as contour canals to give the benefits to the maximum extent possible. These contour canals have to necessary to cross number of ridges and valleys depending upon magnitude of the project. In general, it is noticed that canal alignments are finalized following the shorter routes available to minimize the ultimate length of canal. This would naturally result in the crossing of the canal over major ridges by means of deep cut flumes or tunnels and the negotiation of major valleys by means of level crossings, very high aqueducts or pressure aqueducts. Generally the authorities are hesitant to adopt detour alignments.