The Odisha Water Resources Department has decided to replace the 38-year-old operating manual of Hirakud reservoir with a modern, flexible system.
A high-level technical expert committee, formed jointly with the Central Water Commission (CWC) and involving engineers from both Odisha and Chhattisgarh, will review the 1988 “rule curve” that still dictates how much water the dam stores and releases each month.
Engineer-in-Chief Dillip Kumar Rout said flood control now stands as the department’s highest priority. “Hirakud was originally conceived to tame the Mahanadi. That purpose remains the foundation of our future strategy,” he said.
A separate team of retired chief engineers based at Burla already reviews reservoir levels and inflows every month. The department maintains a 24-hour watch across the entire basin. Separate operating guidelines exist for the upper catchment in Chhattisgarh and the lower reaches in Odisha; officials say these rules are being enforced strictly.
Normally, the reservoir is expected to fill by 21 September as monsoon flows ease. This year successive low-pressure systems and heavy rain have complicated operations. Climate change, unpredictable rainfall and the large number of barrages built upstream have altered the pattern of water arriving at Hirakud. Officials admit the 1988 rule curve, drawn up for a different hydrological era, frequently creates operational difficulties.
The new committee will recommend a “dynamic” rule curve that uses real-time satellite data and modern forecasting instead of fixed monthly targets. The goal is to keep enough water for irrigation and other uses while leaving enough empty space to absorb sudden flood peaks and protect the densely populated coastal districts of Kataka, Puri, Jagatsinghpur and Kendrapada.
The same panel is collecting detailed data on annual water availability, actual use and reservoir capacities across the basin. Officials caution that the final yield figures of the Mahanadi are yet to be settled at the CWC level. On the basis of usable dependability, the annual yield of the entire basin is assessed to be within 50 million acre-feet (MAF). Catchment yields in Chhattisgarh and Odisha are almost fifty-fifty.
Officials hope these figures will eventually support a durable water-sharing agreement between the two states and also serve as technical input for the Mahanadi Water Disputes Tribunal.
Er. Rout said a scientifically revised rule curve would make flood management more organised, safer and evidence-based. For millions who live along the Mahanadi — still called Odisha’s lifeline — the review is being presented as a chance to reduce the cycle of sudden inundation that has repeatedly hit the delta even after the dam was built.
Notably, the Mahanadi basin has a total catchment area of about 1.41 lakh square kilometres. Of this, 53 per cent lies in Chhattisgarh, 46 per cent in Odisha, and the remaining 1 per cent is spread across Madhya Pradesh, Jharkhand and Maharashtra.
