Mahanadi Flood Alert: Why Odisha Faces Flooding Almost Every Monsoon

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The flood situation in Odisha remains serious after heavy monsoon rains caused the Mahanadi River to swell beyond danger levels at several locations. Water levels have also risen in the Kathajodi, Daya, and Bhargavi rivers, prompting flood alerts for downstream districts.

To manage the rising reservoir, the Hirakud Dam has been releasing water through 22 gates, leading the Odisha government to place 10 downstream districts-Sambalpur, Subarnapur (Sonepur), Boudh, Angul, Cuttack, Nayagarh, Puri, Jagatsinghpur, Kendrapara, and Khordha-on high alert.

Photo Credit: Instagram@ambarishpadhee/mybhubaneswar

Flooding has been reported in districts like Balasore, Bhadrak, Jajpur, Mayurbhanj, and Keonjhar, where roads, villages, and farmlands remain inundated. According to Chief Minister Mohan Charan Majhi, around 8 lakh people have been affected by the floods across the state.

The latest flood situation has once again raised an important question: Why does Odisha experience severe flooding almost every monsoon?

1. Heavy Rainfall Across The Mahanadi Basin

The Mahanadi is a monsoon-fed river, receiving most of its annual rainfall between June and September. Intense rainfall over the river basin generates huge volumes of water that eventually flow downstream into Odisha. According to the India-WRIS (Water Resources Information System) and the India Meteorological Department (IMD), the basin receives the bulk of its annual rainfall during the southwest monsoon, making it highly susceptible to flooding.

2. Rainfall In Chhattisgarh Also Impacts Odisha

Floods in Odisha are often driven by heavy rainfall in the upper catchment areas of Chhattisgarh. Even if coastal Odisha receives less rain, water flowing downstream from the upper basin can rapidly raise river levels. The Central Water Commission (CWC) regularly monitors upstream inflows and issues flood forecasts for downstream regions based on rainfall and river discharge across the Mahanadi basin.

3. The Hirakud Dam Helps Reduce Flood Risk But It Has Limits

The Hirakud Dam was built primarily for flood moderation, irrigation, and hydropower generation. According to the Department of Water Resources, Government of Odisha, the reservoir stores excess monsoon water to reduce flood peaks. However, when inflows become exceptionally high, controlled releases are necessary to ensure the dam's safety. During extreme weather events, these releases can contribute to higher river levels downstream, although the dam continues to play a crucial role in reducing the severity of floods.

4. Odisha's Delta Is Naturally Flood-Prone

As the Mahanadi approaches the Bay of Bengal, it branches into distributaries such as the Kathajodi, Kuakhai, Daya, Bhargavi, and Devi rivers. This creates a vast, low-lying delta where floodwaters spread quickly during periods of high discharge. The Odisha State Disaster Management Authority (OSDMA) identifies the Mahanadi delta as one of the state's most flood-prone regions due to its geography and interconnected river network.

5. Silt Reduces The River's Capacity

Over time, silt accumulates on riverbeds, reducing the amount of water the rivers can carry. This makes them more likely to overflow during heavy monsoon rains. The Odisha State Disaster Management Authority (OSDMA) notes that sedimentation reduces the carrying capacity of rivers, increasing the risk of flooding during periods of high discharge.

6. High Tide Can Worsen Flooding

When heavy river discharge coincides with high tide along the Bay of Bengal, floodwaters drain more slowly into the sea. This can worsen flooding in low-lying coastal districts. According to the Odisha State Disaster Management Authority (OSDMA), high tides can impede the drainage of floodwaters from the Mahanadi delta, prolonging inundation in vulnerable areas.

7. Climate Change Is Increasing Extreme Rainfall

Scientists say climate change is contributing to more intense rainfall events, resulting in larger volumes of runoff over shorter periods. This increases the risk of rivers overflowing during the monsoon. The Intergovernmental Panel on Climate Change (IPCC) has reported that global warming is increasing the intensity of extreme precipitation events in many regions, including South Asia, making flood risks more severe.

Understanding Odisha's Recurring Flood Challenge

The recurring floods in Odisha are the result of several interconnected factors, from heavy upstream rainfall and the Mahanadi's vast basin to its low-lying delta and changing climate patterns. While floods cannot be completely prevented, better forecasting, reservoir management, and disaster preparedness can help reduce their impact and improve resilience during every monsoon season.