Conjunctive Use of Surface and Ground Water for Irrigation with Special Reference to Pap Basin, Tamil Nadu

The concept of conjunctive use of water resources requires judicious planning and policy implementation to utilize the surface and groundwater resources. The concept of integrated hydro-systems management was recognized by the practioners' since early 1970's. Earlier, studies on conjunctive use mostly focused when situations such as water logging and salinization problems were caused by intensive irrigation in many canal commands. But shortages of surface water supplies also necessitated the development of groundwater in many canal commands. In such situation, groundwater can be used along with surface water supplies in a profitable way. The present study was carried out in Parambikulam- Aliyar - Palar basin, Coimbatore, Tamil Nadu, where the command area is divided into two zones which receive the canal supply once in alternate years. The water demand and available water resources in the study area were evaluated considering surface water and groundwater and rainfall. The aquifer response and recharge due to rainfall in the PAP basin were studied. The efficiency of canal water delivery system in 4(L) distributory and evaluation of the conjunctive use of available water resources and its optimal allocation with the objective of obtaining maximum net benefits in 4(L) distributory of the Pollachi canal were studied. This paper presents a simple economic- engineering optimization model to explore the possibilities of conjunctive use of surface and groundwater using linear programming, and to arrive at an optimal cropping pattern for optimal utilization of water for maximizing net benefits.