Study of Lake Tapping Technology for Sustainable Hydropower Development and Irrigation at Kallammawadi Dam

Abstract Lake tapping provides an option for accessing water that is stored below the level served effectively by a standard intake. This study explores the possibility of applying such a system at Kallammawadi Dam (also known as Dudhganga Dam) in Bhudargad Taluka of Kolhapur District, Maharashtra. It is presented as a preliminary technical review rather than an end design proposal. The working concept and relevant literature of lake tapping are discussed. The study highlights the investigations that would be required prior to a construction decision. Particular attention is given to the reservoir conditions, geology, tunnel alignment, hydraulic behaviour, structural stability, environmental considerations and safety during connection of the tunnel to the reservoir. Experience from the Koyna Hydroelectric Project has demonstrated that lake tapping can be used as an alternative intake arrangement for hydropower development. However, the information available for Kallammawadi Dam is not sufficient to identify a final tapping location, tunnel size, and discharge or power output. A site-specific feasibility investigation is recommended. If technical, economic and environmental conditions prove favourable, then this approach could lead to a more productive use of stored water and potentially offer an opportunity for additional hydropower development while serving water-management objectives.