Odisha is set to overhaul the operating rules of the Hirakud Dam for the first time in 38 years, as changing rainfall patterns, climate change and the growing number of barrages upstream have significantly altered the flow of the Mahanadi River.

A high-level technical expert committee, formed jointly with the Central Water Commission (CWC) and comprising engineers from Odisha and Chhattisgarh, will review the 1988 “rule curve” that governs the amount of water the reservoir should store and release during different months.

Engineer-in-Chief Dillip Kumar Rout said flood control remains the department’s top 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 in Burla already conducts monthly reviews of reservoir levels and inflows. The department also maintains round-the-clock monitoring across the Mahanadi basin. Separate operating guidelines are in place for the upper catchment in Chhattisgarh and the lower reaches in Odisha, with officials stating that these guidelines are being strictly followed.

Under normal conditions, Hirakud Reservoir is expected to reach full capacity by September 21 as monsoon flows begin to decline. However, this year, a series of low-pressure systems and periods of heavy rainfall have made reservoir management more challenging.

Officials say climate change, increasingly unpredictable rainfall and the construction of numerous upstream barrages have changed the pattern and timing of water reaching Hirakud. The existing 1988 rule curve was designed for a different hydrological environment and is now creating operational challenges.

The new committee is expected to recommend a more “dynamic” rule curve based on real-time satellite information, modern weather forecasting and updated hydrological data rather than relying solely on fixed monthly storage targets.

The proposed system aims to maintain adequate water for irrigation and other requirements while preserving sufficient storage space to absorb sudden flood peaks. This is particularly important for protecting densely populated coastal districts such as Cuttack, Puri, Jagatsinghpur and Kendrapada.

The committee is also gathering detailed information on annual water availability, actual water utilisation and reservoir capacities throughout the Mahanadi basin. A preliminary assessment estimates the river’s total annual yield at 62.36 million acre-feet (MAF), with Odisha’s share estimated at 33.17 MAF and Chhattisgarh’s at 28.94 MAF.

Officials hope the updated data will eventually contribute to a more durable water-sharing arrangement between Odisha and Chhattisgarh. The findings are also expected to provide technical inputs for proceedings before the Mahanadi Water Disputes Tribunal.

Rout said a scientifically updated rule curve would make flood management more systematic, safer and evidence-based. For millions of people living along the Mahanadi, often described as Odisha’s lifeline, the review is being seen as an opportunity to improve flood management and reduce the recurring risk of inundation across the delta, even decades after the construction of Hirakud Dam.