With better dam management, could the north Karnataka floods have been mitigated?

Dam management officials seem to have let the reservoirs fill up in order to mitigate a future water crisis – except, this may have ended up worsening the current flooding.
With better dam management, could the north Karnataka floods have been mitigated?
With better dam management, could the north Karnataka floods have been mitigated?
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It was an agonising wait for 37-year-old Mahantesh Baburao Uppari and his family of four, who were stranded on the rooftop for a full day before the NDRF personnel rescued them from their rooftop on August 7. Swirling waters of the Ghataprabha river had submerged his village of Melavanki in Karnataka’s Belagavi district on August 6, the day the sluice gates of the Hidkal Dam on the Ghataprabha river were thrown open.

Like Melavanki, several villages across north Karnataka were hit by unprecedented rains and floods last week. The worst-hit district in north Karnataka, Belagavi, saw 13 deaths and over four lakh people were displaced from their homes. Three people were killed in Bagalakote, while 1.25 lakh people were evacuated.  

As the rains abate and the waters slowly recede, the question is – could the floods have been mitigated in north Karnataka? Did the delay in opening the gates of the dams exacerbate the disaster in the region? Or did record rains in a short span of time give officials in the state little room to manoeuvre?    

The rainfall

For two weeks, Belagavi witnessed torrential rainfall. Between July 25 and July 31, the district recorded 86.1 mm rainfall against the normal of 41.2 mm. That’s 109% above normal. But it was the week between August 1 and August 7 that was destructive. The district, according to IMD figures, saw 292 mm of rainfall in one week, against the normal of 38.8 mm – a whopping 652% excess.

Neighbouring Bagalakote also witnessed incessant rainfall, with the district receiving 17% excess rainfall between July 25 and 31. Like Belagavi, the following week saw massive rainfall with Bagalakote recording 41 mm of rainfall against the normal of 18.5 mm. In IMD’s words, that’s a large excess of 121%.

And while these two weeks alone caused enough devastation in the districts and the region as a whole, data from the Met Department shows that since the onset of the monsoon, there has been consistent rainfall across the weeks in the two districts. With the rains continuously lashing the two districts leading up to the crucial week of August 1 to 7, the waters in the three dams were fast filling up, even as the rivers were in spate.

While the Krishna River and its tributaries Ghataprabha and Malaprabha flow through the Bagalakote district, in Belagavi much of the devastation was on account of the latter two rivers. 

But with Karnataka reeling under its seventh consecutive drought, and with the Ghataprabha and Malaprabha rivers running dry for most of the last decade, officials in the state were letting the dams fill up to mitigate a future water crisis. They were frugal in releasing water from the Hidkal, Naviluteertha and the Alamatti dams, even during peak rainfall. And this, according to experts, was perhaps a reason why the flooding was worse than it should have been.

Himanshu Thakkar from the South Asia Network on Dams, Rivers and People (SANDRP) argues that dam rules were violated as all three dams were nearly full even before the completion of the monsoon.

Alamatti Dam

Built over the Krishna River, the situation in Alamatti Dam, situated on the edge of Bagalakote and Bijapur districts, has been alarming. 

The Krishna River, which originates in Maharashtra, flows through Karnataka, Telangana and Andhra Pradesh before draining into the Bay of Bengal. The heavy rainfall in Maharashtra resulted in increased water inflow in the Krishna River. By July 26, the Almatti Dam, which is downstream, had reached a storage capacity of 94.94%. 

But despite an inflow of 11,679 cusecs, the outflow was minimal at 128 cusecs on July 26. Two days later, on July 28, the total capacity touched 96.45%, and the Alamatti dam officials released 27,095 cusecs of water.

Three days later, on July 31, the outflow rapidly increased to 1,76,297 cusecs, which was more than the inflow of 1,19,850 cusecs. With such a sudden increase in water release, the water level in the dam had dropped to 90.44% of its storage capacity, according to Karnataka State Natural Disaster Monitoring Centre (KSNDMC) data.

On August 4, as the situation turned grim in the northern parts of the state, Karnataka Chief Minister BS Yediyurappa wrote to his counterpart in Maharashtra, Devendra Fadnavis, requesting him to regulate the outflow of water from the dams upstream of the Krishna River. The next day, the Maharashtra CM in turn requested Yediyurappa to release more water from the Alamatti Dam as the severe backlog of water was affecting villages in Maharashtra.

On August 5, Alamatti dam officials told TNM that they increased the outflow to 2,90,117 cusecs, bringing down the storage capacity to 78%. However, the unabated rainfall led Alamatti dam officials to release 4.5 lakh cusecs of water just three days later, thereby inundating villages in Bagalakote, Bijapur and Raichur districts of Karnataka. As of August 8, the Alamatti dam had reduced its storage capacity to 67.53% to make room for the rapid inflow of water.  

Since then, however, the outflow has continued to increase, touching 5.7 lakh cusecs against an inflow of 6.11 lakh as on August 13, breaking a 14-year record. In 2005, 4.45 lakh cusecs were released, which was the highest outflow until now.  

And across several other dams in the state, a similar situation was seen.

Naviluteertha Dam

Data from KSNDMC shows that on July 31, the Naviluteertha Dam had reached 56.24% of its storage capacity. By August 5, the torrential rains ensured that the dam had reached a capacity of 78.84%, according to KSNDMC. The outflow, however, was marginal at 250 cusecs. The sluice gates of the Naviluteertha Dam were opened on August 6, with outflow suddenly shooting up to 50,000 cusecs. 

Despite the gates being opened, the dam saw its total capacity hit 92.48% on August 8, shows CWC data. The same day, officials at the Naviluteertha Dam told TNM that outflow had been increased to over 1 lakh cusecs.

Hidkal Dam

Data from KSNDMC shows that on July 31, the Hidkal Dam on Ghataprabha River had reached 64.82% of its total storage capacity. But in just five days, with the intensity of the rain increasing, the dam had reached 92.07% of its capacity on August 5. However, the outflow continued to be marginal at 2,432 cusecs, against the inflow of 47,577 cusecs.

It was only a day later, on August 6, that the sluice gates of the Hidkal dam were thrown open.  And in a span of one day, the outflow drastically jumped to 1,00,945 cusecs, according to officials monitoring the dam.

Figures from the Central Water Commission (CWC) show that by August 8, Hidkal dam had reached 662.03 metres against the Full Reservoir Level (FRL) of 662.95 metres, giving dam operators just 0.92 m of leeway to manage the water level. The huge inflows and the uneven corresponding outflow of water from the dam resulted in massive inundation of villages downstream.

‘Dam management rules violated’

Himanshu Thakkar of SANDRP points out, “With the Ghataprabha, Malaprabha and Alamatti dams, the data clearly shows that the operators violated the rule curve.” A rule curve defines the procedure on how dam operators must approve filling up the reservoirs. “The dams have to be filled up in different stages and at different points of time. The division should be such that by the end of the monsoon, the dams must either reach full reservoir limit, or must be nearly full. Of course, if the rainfall is low, it is not possible to reach full storage capacity. But if it rains, the dams cannot be close to full before the monsoon ends,” he explains.

He further alleges that dam operators exacerbated the floods in north Karnataka by not staggering the release, even after warnings were issued by the Met Department. "In addition, basic dam management rules were also violated. The IMD gives rainfall warning five days in advance. Even if the dam operators had started releasing water when the warning came in, they could have reduced the scale of the disaster. While releasing water, the operators must calculate the water carrying capacity of the river downstream. If excess water is released, obviously it will flood the catchment. Even though the IMD warning was there, and they knew the carrying capacity, water was not released from the dam on time, which is why there is a disaster,” he alleges. 

What the dam officials say

According to a senior official at the Hidkal Dam, neither the state government, nor the officers monitoring the dam expected large amounts of rainfall. “The last time it flooded, and not at this scale too, was in 2005,” the official says.

Furthermore, the official says that the idea was to conserve water for the future, as opposed to preparing for a flood. He points out that since 2011, the Hidkal dam has never reached its full capacity and hence, the dam authorities had formulated the flood management and dam management plans with respect to conserving water as much as possible. This despite the warnings issued by the Indian Meteorological Department and the Karnataka State Natural Disaster Monitoring Centre.

“We had issued extremely heavy rainfall warning in the Krishna river basin on July 25 itself. Generally, our job is to inform the government and dam management authorities about the predictions we make. It is up to them to formulate the policy regarding outflow of water,” a senior hydrologist with KSNDMC tells TNM.

However, officials at Hidkal and Naviluteertha dams allege that they had standing orders from the Karnataka government that the reservoir must fill up to 96% before releasing moderately large quantities of water. “The government approves the Dam Management Chart. We have to follow it. We cannot make decisions on releasing water willy-nilly. We will get suspended if we do not follow the chart,” an official with the Naviluteertha Dam tells TNM. The official also says that the government had asked them to refrain from releasing excess water in mid-July since the monsoon had not yet set in properly in several parts of the state.

Although the rainfall was unprecedented in Belagavi and Bagalakote, could better management of the reservoirs have reduced the area of the floods?

The Karnataka government’s stance

TNM spoke to top officials in the Karnataka Department of Water Resources. According to its Principal Secretary Rakesh Singh, there was no prediction of such unprecedented rainfall and that the government had formulated plans based on the averages and probabilities of rainfall in the region.

“This year has been an exception. Naviluteertha on Malaprabha was built in 1973. That’s just 46 years ago. It has filled up (completely) only six times in the last 46 years. This time was the worst. People who have understood this river say it doesn’t overflow. The rains started on July 28. There was no prediction of these rains, they were unprecedented,” Rakesh Singh says.

Another official with the Department of Water Resources says that the first priority was drinking water, when the dam management plan was formulated in view of the recurring droughts in Karnataka.

“The last few years have been drought. If we release water in the first cycle, the farmer goes for preparation of fields and for sowing. If we aren’t able to release water in the second, third or fourth cycle, then we have adversely impacted the farmer. We only release water when it reaches a particular level to ensure crop irrigation,” the official says.

The official also suggested that the death toll in Belagavi was aggravated by the fact that residents have over the years encroached along the river.

“If you see, most of the Krishna river basin’s catchment area has been encroached by people. They have their farm lands and homes so close to the dams and rivers. People don’t want to evacuate their houses until the last minute. They say, we know nature better than you. How can we convince such people? Besides, the Revenue Department does not take these encroachments seriously,” says the official.

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