Nabarangpur Flood Emergency: Ghatakusumi Breaches Historic Flood Level, 1973 Record Now Under Threat | Exclusive

Bhubaneswar: The flood emergency in Nabarangpur has taken a dangerous new turn. While the Indravati at the Nabarangpur Base station is yet to reach its historic 1973 flood peak, an upstream station at Ghatakusumi has already breached its Highest Flood Level (HFL) and is witnessing an extraordinary flash-flood surge.

The latest Central Water Commission hydrograph at Ghatakusumi shows the water level shooting up in a near-vertical rise and moving above the historical red HFL (Highest Flood Level) line. More alarming, the river is rising at around 40 cm per hour.

That changes the flood calculation for Nabarangpur town.

The huge flood wave now surging through the upper river system will progressively compound the flood pressure downstream.

At the Nabarangpur Base station, the Indravati was at 557.395 metres at 8 pm on Sunday, just 0.355 metres below its Danger Level of 557.75 metres and 1.935 metres below its all-time Highest Flood Level of 559.33 metres, recorded on July 7, 1973.

With the CWC already warning of an above-normal flood, an upstream station already breaching its historical flood level and the IMD's Red Warning for extremely heavy rainfall still in force, the question confronting Nabarangpur is no longer whether floodwaters will rise further.

The bigger question now is: Will the compounding flood wave push the Indravati at Nabarangpur town beyond its historic 1973 level?

Ghatakusumi Breach Changes the Flood Picture

Until now, the focus was largely on the rapidly rising water level at the Nabarangpur Base station.

But the latest hydrograph from Ghatakusumi provides the first major indication of how severe the flood generation is in the upper catchment.

Unlike the relatively steady rise at Nabarangpur town, Ghatakusumi has witnessed what appears to be a flash-flood explosion. The river level has surged almost vertically, crossed its historical HFL and is continuing to rise at an extraordinary pace.

A rise of around 40 cm per hour indicates that an enormous volume of local runoff is moving through the upper tributary system.

This is crucial because Ghatakusumi and Nabarangpur Base are not showing two unrelated flood events. They represent two stages of the same developing hydrological crisis.

At Ghatakusumi, the flood is being driven by a sudden and violent flash-runoff response from the upper catchment.

At Nabarangpur town, that water is expected to progressively accumulate into the main Indravati channel, adding to the floodwaters already generated by intense rainfall in the downstream and local catchment.

Two Stations, Two Flood Behaviours

The contrast between the two stations explains why the Nabarangpur situation could worsen even if the river rise at the Base station appears relatively less explosive.

At Ghatakusumi, the flood is behaving like a classic flash flood. The upper catchment has generated a sudden surge that has already overwhelmed the river's historical flood benchmark.

At Nabarangpur Base, the flood is behaving as a compounded mainstem flood. Water from upstream locations and tributaries gradually travels downstream, joining the local runoff and filling the main Indravati channel.

This means the Nabarangpur hydrograph can initially appear to rise more steadily than Ghatakusumi even as the larger flood wave continues to build.

The upstream surge is therefore a major warning signal for what may still be coming downstream.

The 1973 Shadow Has Become More Serious

For Nabarangpur, the historic benchmark remains 559.33 metres, the Highest Flood Level recorded at the Base station on July 7, 1973.

As of 8 pm on Sunday, the river stood at 557.395 metres.

The remaining gap of 1.935 metres is still significant. Therefore, it cannot be stated as a certainty that the 1973 record will be breached.

But the flood scenario has changed sharply after Ghatakusumi crossed its own historical HFL.

The Indravati at Nabarangpur is already:

• 1.645 metres above its Warning Level of 555.75 metres

• Just 0.355 metres below its Danger Level of 557.75 metres

• Rising towards the historic 559.33-metre HFL

• Receiving the combined impact of intense local runoff and the developing upstream flood wave

The CWC's above-normal flood forecast and the Red Warning for extremely heavy rainfall add another layer of uncertainty.

If the extreme rainfall continues and the upstream flood wave reaches Nabarangpur at a time when the main channel is already close to danger level, the 1973 benchmark could come under serious challenge.

189 mm Rainfall Has Already Triggered Massive Runoff

The hydrological response is being driven by exceptional rainfall across Nabarangpur district.

Over the past 24 hours, Nabarangpur block received 189 mm rainfall. Tentulikhunti also recorded 189 mm, while Paparahandi received 175 mm.

Such rainfall over a short duration is enough to rapidly convert local streams and tributaries into high-velocity flood channels.

The Red Warning now raises the risk of another burst of intense rainfall over catchments that have already produced a massive runoff response.

This creates a dangerous compounding cycle:

Extreme Rainfall → Flash Runoff in Upper Catchment → Ghatakusumi Breaches HFL → Flood Wave Moves Downstream → Main Indravati Swells at Nabarangpur → Further Rainfall Adds Fresh Runoff

Will Upper Indravati Open Spillway Gates?

The spillway question has now become more serious, but the latest flood data must be read carefully.

The Upper Indravati reservoir still has considerable physical storage space.

Its water level is at 635.68 metres, against the Full Reservoir Level of 642 metres, leaving around 6.32 metres of headroom. The available storage cushion is about 67,758 hectare metres.

However, the reservoir is rising.

Inflow is around 751.19 cumecs, while the total outflow is only 14.10 cumecs, largely through power and canal operations.

The reservoir's present storage level means an immediate spillway opening cannot be assumed merely from the available capacity figures. But the situation is no longer static.

The new factor is the extreme upstream flash flood.

If the rapidly rising flood wave represented at Ghatakusumi is part of the reservoir's effective catchment response, or if further extreme rainfall sharply increases inflow into Upper Indravati, the reservoir could start filling its available cushion much faster than current storage percentages suggest.

That would increase pressure on dam operators to make a decision on controlled releases.

A Difficult Operational Choice

The reservoir authorities are effectively facing a flood-management dilemma.

On one side, they have a substantial storage cushion and would ideally want to absorb as much incoming floodwater as possible, especially because the downstream Indravati is already critically high.

On the other side, they cannot allow a rapidly accelerating inflow to consume the available flood cushion so quickly that a much larger release becomes necessary later.

A controlled, precautionary release – if operationally required – would therefore be intended to manage reservoir safety and future inflow pressure.

But it would come at a time when the downstream river is already carrying an extreme flood load.

The key operational question will be whether the incoming flood volume, combined with the Red Warning forecast, begins to exceed the reservoir's projected ability to safely absorb the next flood surge.

If inflows accelerate sharply over the next several hours, controlled spillway operations may become increasingly likely.

However, the timing, number of gates and discharge volume would depend on real-time reservoir inflow, rainfall and the official dam operation protocol.

Why Gate Opening Could Worsen the Downstream Crisis

The biggest concern is the condition of the river downstream.

At Nabarangpur, the Indravati is already only 36 cm below the Danger Level. At Ghatakusumi, historical flood levels have already been breached.

In such a situation, any major additional release into an already swollen downstream system could increase inundation risks in vulnerable riverside areas.

This is why the reservoir operators will have to balance two competing priorities:

Hold water to avoid worsening the downstream flood immediately – or release water in a controlled manner to preserve sufficient safety cushion against a potentially much larger incoming flood wave.

The answer will depend on how the inflow behaves through the night.

The Next 12 Hours Are Now Critical

The Red Warning makes the next 12 hours potentially decisive.

If rainfall weakens and the upstream flood wave begins to flatten, Nabarangpur may avoid the worst-case scenario.

But if another spell of extremely heavy rainfall hits the upper catchment while the Ghatakusumi flood surge is still moving downstream, the Indravati at Nabarangpur could rise much faster than the present hydrograph suggests.

The immediate sequence to watch is:

Ghatakusumi Extreme Flood → Downstream Flood Wave Propagation → Nabarangpur Danger Level Breach → Additional Rainfall Runoff → Rising Reservoir Inflow → Possible Controlled Spillway Decision

For now, the historic 1973 record has already been breached at Ghatakusumi, though the Nabarangpur Base station has not yet reached its own historic peak.

1973 Not Yet at Nabarangpur, But the Flood Has Entered a New Phase

The situation at Nabarangpur can no longer be assessed only through the Base station gauge.

The upstream breach of the historical flood level at Ghatakusumi suggests that the upper river system has already entered an extreme flood phase.

Nabarangpur town is now facing a compounded threat from three directions:

1. Its own intense local runoff

2. The downstream arrival of the upstream flood wave

3. The possibility of further extreme rainfall under the Red Warning

The spillway decision at Upper Indravati could become a fourth pressure point if reservoir inflow accelerates sharply.

The river at Nabarangpur is yet to repeat the historic flood level of 559.33 metres recorded on July 7, 1973. But the margin for comfort is rapidly shrinking.

Ghatakusumi has already crossed its historic flood benchmark. Nabarangpur is just centimetres below danger level. The Red Warning is still active. And a major upstream flood wave is now moving through the Indravati system.

The flood clock for Nabarangpur has entered its most critical phase. 
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