A Modeling System to Evaluate Future Water Allocation Strategies in Complex Basins: A Case Study of the Musi Catchment, India

Sustainable water resources management has become a major issue in recent years due to pressure imposed to the natural system by the increasing needs of more water. The situation is worst in Musi catchment, India due to rapid population growth and over exploitation of ground water. An integrated hydro-economic model for the basin is developed that allows for the analysis of water allocation and use under alternative policy scenarios. The model describes the water supply situation along the river system and the water demands by the various water-using sectors. The modelling approach is based on integrating resource availability and use through a network allocation model (REALM) integrated with an economic model. Resource Allocation Model (REALM) is a network allocation model based on a combination of water balance combined with a linear optimisation algorithm that enables the use of user-defined penalties and priorities to impose constraints and preferential resource use. The economic approach used in this study is based on a benefit cost analysis of different users and the costs of alternative water distribution scenarios. A scenario approach was used to investigate possible changes. Results from the scenario analysis indicate that competition for Musi water is very high. However improvement of existing water distribution systems, waste water recycling, rain water harvesting, urban run-off recycling, crop diversification etc. could alleviate the problem and lead to sustainable use of water resources in the catchment. Hydrological impacts of a number of different scenarios were analysed and presented in this paper.