Assessment of water demand and supply prospects in Kharun river basin

Abstract

The assessment of disparity between water demand and supply has always been a great concern for water managers and policy makers due to unavailability of requisite hydrological information, lack of long term quality data, need of appropriate methodology and complexity of modeling techniques. The aim of this study is to assess supply status of Kharun river of Chhattisgarh state in term of its water availability using probability approach, estimation of projected water demands and its comprehensive water surplus and deficit analysis. The water from Kharun river is utilized mainly to meet domestic water demand of Raipur city, its nearby industrial area, railways and other on-stream demand water demands like Nistari. Estimated total water demand of Kharun river was 65.21 MCM in 2010-11 which will become 174.56 MCM by the year 2050-51. Kharun river has sufficient annual water yield but run dry during lean period. To meet various water demands, river is supplemented from Ravishankarsagar reservoir through canals and links. The demand supply analysis carried out using Flow Duration Curve techniques using 10-daily flow data of Pathardihi Gauge Discharge (G/d) site on Kharun gives an idea of water surplus and deficit scenario of present and future situation. It was seen that when the demand of the river in year 2030 and 2050 will increase to 133 and 175 MCM, the water deficit would becomes 73.56 and 105.33 MCM respectively. The demand deficit analysis gives an idea of variation in water deficit with respect to the variation in water demand and dependability level of the river flow. On comparison of total water demand to be fulfilled from river and water deficit periods, it was observed that, as the water demand increases, the deficit period also increases, the river experiences the deficit earlier when the demands is very high.