1General Manager,
The development of hydropower resources in the Himalayas represents a strategic imperative for the energy security and economic growth of India and Bhutan. However, this potential is constrained by an environment characterized by extreme geotechnical, seismic, and climatic vulnerabilities. Conventional waterproofing methods, such as concrete and asphalt facings, have demonstrated significant inadequacies in these high-stress conditions, frequently failing under structural movements and leading to chronic seepage, operational inefficiency, and accelerated deterioration of critical assets. This paper presents an advanced, flexible polymeric geomembrane waterproofing technology, specifically the CARPI PVC-P system, as a technologically superior and sustainable alternative. The system’s core attributes—nearabsolute impermeability with a hydraulic conductivity of approximately 10-14 m/s, high flexibility with elongation exceeding 200% to accommodate seismic and settlement stresses, and rapid installation protocols—directly address the primary failure modes of rigid linings. The efficacy of this technology is validated through an in-depth analysis of six diverse case studies from India: the Kadamparai, Servalar, and Upper Bhavani dams; the Tanakpur power channel; the Bajoli Holi pressure tunnel; and the Pinnapuram Pumped Storage Project. These examples demonstrate dramatic and sustained reductions in leakage, enhanced operational longevity, and significant construction timeline advantages. Critically, the paper highlights the system's profound sustainability credentials, including a documented reduction in embodied CO2 of up to 70% compared to conventional methods and a fundamental contribution to water security. These benefits position advanced PVC geomembrane technology as an indispensable tool for realizing the "Green Future" envisioned by the India-Bhutan partnership, offering a pathway to de-risk investments, ensure long-term asset resilience, and build a truly sustainable energy infrastructure.
