Design of Desilting Works for Irrigation Systems

Several considerations are used by the Bureau of Reclamation in the design of economic handling systems for the sediment encountered in irrigation systems. The sediment problem usually develops at the place in the stream where heavily laden sediment water is diverted from the river to the canal. To solve this problem some type of sediment excluder or ejector device is selected after considering six basic requirements. A knowledge and understanding of basic hydraulic and sediment principles is necessary to locating the diversion site and selecting the proper type of sediment removal device. Model studies are usually necessary in selecting a favorable location for the intake and in working out the details of arrangement of the structures. A variety of sediment removal devices has been developed from hydraulic model studies and constructed by the Bureau. Some of the devices are guide walls, vortex tubes, surface and bottom vanes, settling basins, drop inlet diversion structures, and Dufour types of automatic sand sluices. Based on the available information, some devices indicate satisfactory performance further substantiated by field personnel operating the diversion works. More studies are to be made in this area.