Design of Single-Chamber Settling Basins

Settling basins are used on irrigation and hydropower channels to remove objectionable sediment of a specified size and quantity. They are formed by widening the approach channel and lowering its floor through an expansion transition, so as to reduce the mean velocity of flow into the basin. However, various combinations of width, depth, and length of the basin are possible to achieve a desired removal efficiency in a given situation. Taking the cost of the straight and prismatic portion of the basin as the criterion, equations have been developed for its best width, depth, and length. The design example of Maneri Bhali Stage II Project in Uttar Pradesh, India, has been worked out by the proposed method and the results are compared with the actual dimensions provided.