Feasibility Study of the Ken Betwa Project using a Super Reservoir Hydrological Model

Abstract

A modeling framework for integrated water resource management at the sub-basin scale for the Ken – Betwa water transfer link (hereafter referred to as KB-link), a part of the Greater Ganges river basin (in India), is presented. A Super Reservoir Model (hereafter referred to as SRM) was developed to explore the adequacy of the combined storage capacity of the linked reservoir system when rainfall, evapo-transpiration, and irrigation demands are considered at sub-annual time scales. Previous official feasibility studies only considered the variability of these same processes at annual time scales. The irrigation demands here are formulated as scenarios and include a number of cropping configuration and planned increases in agricultural production. The SRM assumes that the entire network of reservoirs function as a monolithic storage collection mechanism (or super-reservoir), thereby allowing a simplified mass balance analysis to be conducted. This project demonstrated that the integrated storage volume proposed in the feasibility report for the KB-link is inadequate with probabilities of complete ‘dry-downs’ ranging from 15% to 35%, depending on the scenario. On the practical side, the resulting integrated model of the watershed developed in this project can be used as a tool to facilitate debates and consultations between stakeholders and thus enhance the participatory process. In this sense, this simplified ‘simulator’ is an effective tool to explore the individual and cumulative impacts of water – resource management at sub- basin scale. The Matlab source code is provided upon request.