TR(BR)-143 : Multiobjective optimization of operation of a dam

Abstract

Reservoirs are constructed across the rivers to change the spatial and temporal availability of water in accordance with the requirements of mankind. More than 3000 major and medium dams have already been completed and multipurpose reservoir projects are quite common among them. However, in order to attain maximum benefits from a multipurpose scheme, it is imperative to regulate the reservoirs in the most efficient and judicious manner.

The National Institute of Hydrology is carrying out Comprehensive Hydrological Studies in the Narmada basin. The present report deals with the development of reservoir operation policy for the Bargi reservoir in the Narmada basin. Bargi project is a multipurpose project, meant to serve for irrigation, hydropower generation and water supply for domestic and industrial use. The full irrigation potential of the project has not yet been utilised as the right bank canal is under construction. The canal bed power house is also in planning stage.

In this report, the facilities, that are in operation at present, have been considered for policy development for Bargi reservoir. Power generation through river bed power house and full irrigation demands of the left bank canal have been considered. A linear programming model has been developed for the reservoir for getting the feasible solutions. Then, the simulation analysis of the reservoir operation has been carried out using the 40 years of historical data. A rule curves based policy has been adopted for the operation and the various curves have been optimized using the reliability analysis. Simulation of the operation has also been carried out with the presently followed operation policy and the comparison between the two policies has been made. Trade-off analysis has been carried out between the irrigation demand satisfaction and the hydropower generation and various trade-off curves for different hydropower reliability have been developed. These curves can be used by the authorities in deciding about the proportions of irrigation and hydropower releases. For the conservation regulation of the reservoir, four rule curves have been recommended for different purposes and the operation procedure for the reservoir has been explained.

There is no flood control zone in this reservoir as the FRL corresponds to the top of spillway gates. Hence, no separate flood control policy has been developed for this reservoir. However, the upper rule curve has been derived to keep the reservoir level below FRL as long as there is no effect on the conservation performance of the reservoir.