Identification of Potential Sites for Detention Ponds along the Vrishabhavathi River

Vrishabhavathi Watershed is a constituent of the Arkavathi River Basin, Bangalore Urban and Ramanagara District and covers an area of 360.620Km2, representing seasonally dry tropical climate. In Vrishabhavathi watershed Vrishabhavathi River is the main surface water source which is tributary of river Arkavathy, which joins the Cauvery River at a later stage. Earlier this surface water was mainly used for agricultural purpose and drinking purpose. The watershed lies in Bangalore urban and Bangalore rural area. The stream receives a lot of waste water released from industrial and domestic areas. The water is highly polluted and generates lot of foul smell in the flow stretch in urban region. An attempt has been made to identify the potential sites for detention ponds along the Vrishabhavathi River which will be used to maintain the acceptable water quality for sewage irrigation. For this analysis we need the thematic maps such as Base map, Drainage map, Land use /land cover map and Vrishabhavathi River geometry map. Remote sensing and GIS is useful to identify the sites for detention ponds along the river. By assigning the weights to point feature in Vrishabhavathi River geometry map, then calculating suitability indices potential sites for detention ponds are identified .The water stored in the detention ponds are continuously treated with minimum cost and allowed to flow in the downstream for further oxidation. At suitable location water can be used for sewage irrigation.