OPTIMAL ALLOCATION OF WATER RESOURCES OF BRAHMANI BASIN (ORISSA)

Abstract

The increase in population and consequent rise in the demand of water for irrigation, hydropower generation, domestic, industrial use and maintenance of ecological standards has caused a lot of concern among water resources experts. This has attracted their attention to optimally allocate the available scarce resources to various segments so as to have the maximum net benefit whilelmeeting all requirements of water as mentioned above. The objectives of this study are to optimally allocate water resources to various purposes in the Brahmani basin. These are, (i) To maximize net return from an optimal cropping pattern while meeting minimum food, protein and calorie requirements of the basin population by the year 2051 AD, (ii) To optimize hydropower and firm hydropower generation from reservoirs within the basin, (iii) To determine the optimum size of reservoirs while meeting its objectives as well thus reducing the cost of dam construction. In the present study, to estimate the future demand of water for various purposes, the population growth up to the year 2051 AD has been predicted using the anticipated trend in the basin covering a catchment of 22516 km2. Using this data, requirements of water for various purposes have been estimated. Brahmani is an interstate river but in the present study only the Orissa portion has been taken into account. The availability of water from all sources (surface water and ground water) also has been estimated. To estimate runoff, 75% (for irrigation) and 90% (for hydropower generation) dependable yield has been calculated using flow duration curve. 0 FAO 56 Penman-Monteith method has been used to determine the reference crop evaporation while calculating the gross irrigation requirement (GIR) of different crops.