The storage capacity of the Nangal Dam lake, a critical component of the Bhakra canal system, has reduced by nearly 24 per cent due to heavy accumulation of silt, sparking concerns over its long-term impact on water supply and hydropower generation in northern India.According to data presented in Parliament by Union Jal Shakti Minister in response to a query by Congress MP Manish Tewari, the lake’s storage capacity has declined from its designed level of 25.22 million cubic metres (MCM) to just 19 MCM. This marks a reduction of over 6 MCM, a significant loss for a reservoir that plays a pivotal role in regulating water distribution downstream.The Nangal Dam lake supplies water to the Nangal Hydel Channel, which in turn becomes the Bhakra Main Line, serving Punjab, Haryana, and Delhi. Officials indicated that the reduced capacity may adversely affect discharge levels into the canal system in future, particularly during peak demand periods in the summer months.Sources said that the Bhakra Beas Management Board (BBMB) has taken note of the issue and is considering a proposal to undertake desilting operations in the reservoir. However, the process is fraught with regulatory hurdles.The Nangal Dam Lake has been notified as a wildlife sanctuary and a wetland by the Union government. Additionally, the surrounding area within a 100-metre radius has been designated as an eco-sensitive zone. As a result, any desilting activity would require prior clearance from the Union Ministry of Environment, Forest and Climate Change, making the process both time-consuming and complex.Apart from irrigation, the lake also supports hydropower generation. The Anandpur Sahib Hydel Channel, which also originates from the reservoir, feeds two powerhouses at Ganguwal and Nakkian. These facilities collectively generate approximately 100 MW of electricity for the Punjab State Power Corporation Limited (PSPCL), significantly contributing to the state’s energy needs.Experts warn that continued silt accumulation could impair not only water flow but also the efficiency of turbines in downstream hydropower plants. Reduced water availability and irregular flow patterns may lead to lower electricity generation, particularly during critical demand cycles.The issue has also reignited a broader debate over water resource management and mining practices in the region. Environmentalists and policy observers have questioned why authorities have not prioritised desilting of reservoirs, which contain millions of cubic metres of sand deposited as silt, while natural rivers and hill ecosystems continue to face degradation due to excessive and often illegal mining.