PERFORMANCE EVALUATION OF THE RESERVOIRS – WATER AUDIT P.R. Sarda Research Scholar, Government Engineering College, Aurangabad – 4 3 1 0 0 5 Sarda_purushottam@Rediffmail.com ABSTRACT This work presents an approach for the performance evaluation of reservoirs by using water audit tool. Water auditing is based on water accounting and provides, in turn, the basis for benchmarking of irrigation systems, as well as well-informed operational irrigation planning and strategic investment planning. Water auditing thus helps in identifying the causes of low performance and excessive losses. The service provider can then initiate appropriate action for improvement. The geographical area of Maharashtra is divided into five main river basins with 25 Sub-basins. The 45% area of the state is in deficit and highly deficit in water resource region. One of Major challenges before Water Resources Department is to bring the created irrigation potential under actual utilization. So efforts should be made for efficient utilization of available water. Water Resources Department has concentrated its efforts in that direction. Water Auditing of irrigation systems is one of the sector improvement programmes being implemented since 2003-04. A water audit determines the amount of water used in different sectors, evaporation losses in reservoir and transit losses in distribution system. Water auditing of irrigation projects, is necessary to see that the water use, evaporation and other losses are as per design. Large numbers of Irrigation projects are constructed in Maharashtra to tap the water resources of the state. Irrigation potential to the tune of 4.486 Mha is created by the end of June 2008 through 71 Major, 243 Medium and 2940 state sector minor irrigation projects. During last five years irrigation potential utilization status improved from 1.708 Mha to 2.732 Mha. Introduction Maharashtra at a Glance The geographical area of Maharashtra is 307.78 lacs hectares of which the cultivable area is 225 lacs ha. The area is divided mainly into five major river basins of Godavari, Krishna, Tapi, Narmada and westward flowing the rivers comprising a basin group of 22 narrow sub-basins. The Maharashtra Water and Irrigation Commission (1999) has proposed delineation of five river basins basically into 25 distinct sub basins for planning of water resources development in the State. The categorization of sub basins proposed is solely on the basis of natural availability of water. The basic characteristics of sub basins are dictated by the hydrological regime, which in turn, is a function of climate, rainfall distribution and the type and characteristic of draining area. About 2.5% of the water on the earth is available in fresh form. Out of this 2.5%, about 0.25% is available for irrigation purpose. Worldwide the consumption of water is doubling every two decades. Water audit is the most effective tool for water management. Through audit we identify and quantify what steps can be taken to reduce water use and losses. Water audits trace water use from its point of entry into the facility/system to its discharge into the canal. The audit also identifies and quantifies unaccountable water losses, leaks at each point of use within and around the facility. Water audit at a micro level and possible ways of water use reduction in the typical irrigation. India is one among the top 12 water poor countries with the per capita availability of 1850 m3/person/year as against the world average of 7690 m3/person/year.