Extreme Precipitation Exceeds the Design Thresholds of Indian Dams in Observed and Future Warming Climate

India’s large dams are designed using predefined design thresholds: historical maximum precipitation, design precipitation (100-year return period), and Probable Maximum Precipitation (PMP). However, the occurrence of extreme precipitation raises critical concerns under a warming climate for ensuring the safety of more than 5600 dams. Here, we present the first national-level study on dam infrastructure, assessing whether precipitation events in the observed and future periods exceed the design thresholds for dams. Using long-term observed daily precipitation data (1951-2022), we show that the annual maximum precipitation and the frequency and intensity of precipitation exceeding the 99th percentile threshold have increased significantly (10-40%), especially during the post-1986 period. Moreover, during the post-1986 period, majority of dams experienced frequent intense-precipitation exceeding the historical highest precipitation, design precipitation, and PMP of the pre-1986 period across Indian Subcontinent (especially over West and South Coast). Based on CMIP6-GCMs, our analysis indicates that the number of intense-precipitation events exceeding the design threshold of the historical period (1976-2010) will increase further (around three-times) in the mid (2031-2065) and end (2066-2100) periods, especially under SSP5-8.5. Furthermore, we find that the risk of intense-precipitation events exceeding historical design thresholds is substantially accelerated not only during strong Indian Summer Monsoon (La Niña) but also during weak Indian Summer Monsoon conditions (El Niño conditions), which is projected to compromise dams' safety margins in future warming climate. Overall, our findings suggest that the historical design flood values for dams are no longer safe in the observed and future periods, underscoring the need to reassess them under a warming climate.