11th September,2018
Kerala floods: 1.16 bn cubic m space available in dams, 2.19 bn cubic m inflow in 3 days
A Central Water Commission (CWC) report on the Kerala floods, released Monday, explains how three days of intense rainfall (August 15-17, 414 mm) brought in more water than the state’s dams could accommodate, making it necessary to release water. From the catchment tapped by the dams, excluding barrages, the report estimates that the runoff generated during the three-day period was 2.19 billion cubic metres (BCM), out of a total runoff of 12 BCM for the state. “The total live storage of Kerala is about 5.8 BCM. Even with 20 per cent of the live storage availability on 14 August 2018, the available flood moderation extent would have been only 1.16 BCM against the estimated inflow of 2.19 BCM,” the report states. “It shows that in any case, it was essential to make releases from reservoirs.”
The report refers to two previous floods, in 1924 and 1961. During July 16-18, 1924, heavy rainfall occurred on almost entire Kerala, causing heavy loss of life and property. “The centre of the 1-day and 2-day rainstorm was located at Devikulam in Kerala which recorded 484 mm and 751 mm of rainfall respectively. The centre of 3-day rainstorm was located at Munnar in Kerala which recorded a rainfall of 897 mm in 3 days,” says the report, which also compares the amount of rainfall during the three peak days of 1924 and the three peak days of 2018.
In 1961, floods were unusually heavy both in duration and in intensity of precipitation, with the monsoon getting violent towards the last week of June and in the early days of August. The average rainfall was 56 per cent above normal.
-Indian Express
Further, since Friday, all of CWC’s hydrological observation gauges in Kerala have either gone under water or the agency has lost contact with them, the official said. “Most of our sites are under water since Friday, either submerged by the rising water or our communication has been lost. Gauges are one-two metres above the HFL (highest flood line) and they are all submerged now.”
In April 2018, CWC’s manual termed ‘Standard Operating Procedure for Flood Forecasting’ listed 19 major interstate rivers that were under monitoring. In all, it noted that flood forecasts were being issued by the CWC at 226 stations across these basins. The document listed 24 states in which flood forecasting stations were operational. The CWC issues a level forecast and an inflow forecast.
But to get on the list, the official said, a formal request is required from the state. “The request is often made in the case of interstate rivers since one state might be interested in knowing about the situation in a neighbouring state with which it shares a river. However… Kerala… largely has intra-state rivers that start from Western Ghats,” the official said.
Mullaperiyar is the only exception, the official said, but it was monitored by a separate committee.
17/8/18
More than 160 people have died and lakhs left homeless as rain continues to batter Kerala, which is reeling under the worst flood it has witnessed since 1924.
Even as the Armed Forces and the National Disaster Response Force are joined by the local fishermen in rescue and relief operations, the fate of millions hang in the balance — according to reports, 2,23,000 people have been accommodated in 1 ,568 relief camps across the state, road and rail transport are completely suspended in several areas, hospitals battle a lack of liquid oxygen and diesel, and crops and property worth Rs8,000 crore have been damaged.
But rain fury alone is not responsible for the state’s miseries.
For the first time ever, shutters of 35 of Kerala’s 39 dams were opened, within days of each other. At a time when the state was already receiving more rainfall than usual, the excess water from the dams flooded the rivers. The adjoining areas were inundated, houses and roads submerged in water, residents forced to flee.
What is more, according to some locals, proper warnings were not given to them about the sluice gates opening, leaving them with little time to gather their belongings and move to safety.
Why were the dams not opened well in time, before the rains got worse? Why did authorities wait for water levels to reach the danger mark, necessitating the opening of all the dam gates around the same time?
Even as the decision to open the gates was being delayed, why were people in the nearby areas not moved to safety?
These are some of the questions the Pinarayi Vijayan government needs to answer.
An article in Firstpost quotes Murali Thummarukudy, chief of Disaster Risk Reduction in the United Nations Environment Programme (UNEP), as saying: "Sitting at Geneva, I had on June 14 cautioned that the reservoirs will be filled by July. I had made the prediction based on the experience in Thailand and Pakistan. Unfortunately, our engineers did not foresee this.”
Residents, too, have been quoted as saying that Idamalayar dam in Ernakulam and Banasara Sagar dam in Wayanad were opened without giving them adequate warning, and all the five shutters of the Cheruthoni dam were opened together, instead of opening them phase-wise with simultaneous evacuation of people.
Firstpost has quoted dam safety expert N Sasidharan as saying: “The authorities waited till the water level in the Idamalayar reservoir reached its capacity of 169 feet. If it was opened when the water level reached 165 feet, it would not have necessitated the evacuation of many people in the downstream areas. This is the result of poor planning by the disaster management authority.”
The same complaint has been made about the Idukki dam too, opened for the first time since 1992. Warnings about Idukki were being raised as early as July 31. But that time, state water resources minister Mathew T Thomas had said there was no need for even a trial run of opening the dam’s sluice gates, as the “water level was rising only by 0.02 feet an hour”.
Warnings about water levels in Idukki were being raised as early as July 31. (Photo: PTI)
The South Asia Network on Dams, Rivers and People (SANDRP) has cited how the water level in Idukki rose faster because two of its six turbines, that use water for power generation, were non-functional. One of these was shut down on June 26 for annual maintenance. What was the point of shutting down a turbine for maintenance just before the monsoon?
Also, as late as on August 17, Kerala and Tamil Nadu were arguing over the Mullaperiyar Dam, which is managed by Tamil Nadu.
Clearly, as disaster surged close, the state government was caught napping. Contrast this with Odisha in 2013, when, during the Cyclone Phailin, timely warnings and evacuation of people had ensured that the loss of lives was minimised — 38, as compared with the 167 in Kerala already. A report by the United Nations Environment Programme’s Global Environment Alert Service had said about the Odisha government: “Government cooperation, preparedness at the community level, early warning communication and lessons learned from Cyclone 05B [in 1999], contributed to the successful evacuation operation, effective preparation activities and impact mitigation.”
If resource-strapped Odisha could have prepared itself so well for a natural disaster, could not richer, more developed Kerala have done the same?
Even apart from this, there is a lot the Kerala government needs to answer for.
In 2011, the Gadgil Committee made several suggestions to Kerala to conserve the ecologically fragile Western Ghats. The recommendations included restrictions on mining and quarrying, on use of land for non-forest purposes, and on the unabated proliferation of high-rise buildings. The government had rejected the report.
Now, environmentalists are pointing out that widespread and uncontrolled quarrying has led to the mudslides the state is witnessing, which are responsible for the most number of deaths in these floods.
Once the flood and fury recede, there are many lessons the government of Kerala needs to take from this disaster.
-DailyO
17/8/2018
12-8-2018
Kerala rains; Even after a discharge of 50 cubic metres per second, the reservoir has continued to rise, and the discharge will be increased to 100 cubic metres per second from 7 am Friday.
For only the third time since the Idukki dams system in Kerala was commissioned in 1975, one of the five shutters at Cheruthoni was opened Thursday (the earlier occasions were in 1981 and 1992) after water in the reservoir rose to 2,399.04 ft, precariously close to its full storage level of 2,403 ft. Even after a discharge of 50 cubic metres per second, the reservoir has continued to rise, and the discharge will be increased to 100 cubic metres per second from 7 am Friday.
Rain and reservoir
The lake sprawls across Kerala’s lifeline Periyar river, and was created by the arch dam of Idukki, and the smaller Cheruthoni and Kulamavu dams. Incessant rain since the onset of the monsoon has left Idukki and other reservoirs downstream brimming. While Kerala as a whole has received 15% excess rain, Idukki district got 41% excess until August 8.
Full and overflowing
The Idukki arch dam has no shutters. The Kulamavu dam has penstock pipes that carry water to an underground power station at Moolamattam 43 km away. The water from the reservoir is used to run six generators with a total installed capacity of 780 MW.
Shutters of Cheruthoni dam are opened when the dam reaches full reservoir level. At Panamkutty downstream from Cheruthoni, a tributary of the Periyar called Mudirapuzhayar joins the flow from the dam. At Kallarkutty on the Mudirapuzhayar stands a power generation dam with a storage of 457 ft above sea level — this dam is currently overflowing, boosting the flow in the Periyar. A little ahead stands the Lower Periyar dam, which, too, is overflowing.
Further on its journey towards the sea, the Periyar is joined by a tributary called Edamalayar, which has a dam by the same name. The shutters of Edamalayar dam were opened Thursday. Next along the route is the Bhoothathankettu dam in Ernakulam district. The Periyar then winds its way through Kalady and Aluva on the last leg of its journey to drain into the Arabian Sea 24 km north of Kochi. Another branch of the river flows from Aluva to Kochi’s Udyogamandal before merging with the backwaters.
Threat to Kochi airport
In its journey to the sea, the Periyar comes within 2 km of Kochi’s international airport, the runway of which was built after reclaiming a paddy field. A stream called Chengalthodu drains water from the airport into the Periyar. When the Edamalayar dam was opened in 2013, water had flooded the runway; fears that the rising Periyar would also lift the Chengalthodu led to operations at the airport being suspended temporarily Thursday afternoon.
A first this monsoon
On both earlier occasions, the Idukki dam was opened in October, during the northeast monsoon. This is the first southwest monsoon that has seen the dam being opened, and when the Edamalayar dam too, has been opened.
-Indian Express
Idukki Dam releases water when Kerala is in Floods: Could this have been avoided?
10-8-2018
Kerala is facing serious floods. Army, Navy, NDRF, neighbouring states are all out. Dozens of people have died, landslides happening, houses washed away, the whole machinery is out to deal with the crisis.
In this flood crisis, Idukki & Idamalayar two of the Kerala’s biggest dams along with about two dozen others, are releasing water, adding to the floods and the disaster. Why are Idukki and Idamalayar, both having live storage capacity above a Billion Cubic Meters, releasing water NOW, when whole of Kerala is facing floods due to recent excessive rains? Standard excuse: The dams are full and they have no option but to release the water, they cannot store more. But why did they wait to start releasing water till the dams are full and they are faced with TINA: There is No Alternative. This love to be in TINA situation seems like a disease affecting all dam operators.
There are still two months of South West Monsoon for Kerala. Then large parts of Kerala also get benefits from North East monsoon that follows in Oct-Dec. In fact, the only two occasions (1981 and 1992) since the Idukki Dam was commissioned in 1975, were both during North East monsoon, never in SW monsoon. So they could have easily taken advance action to release water from Idukki when Kerala was not facing floods. They obviously did not and now, when Kerala is facing floods, Idukki is adding to Kerala’s misery.
In fact, just about ten days back, on July 31, 2018[i], the media was full of stories of possible release of water with water level in Idukki crossing 2395 ft, with FRL at 2403 ft. If they had started water in the intervening relatively dry period, Idukki dam need not have added to Kerala’s flood disaster misery. They did not. WHY? Why they again waited to be in TINA state when Kerala is also facing floods?
In fact, basic objective of Idukki Dam is power generation. Idukki dam has six turbines with 130 MW capacity each. One expected that this year Idukki power generation would have broken all records, since never before has the dam water level and inflows into the dam been so high. But when one looks at daily and monthly power generation figures from National Power Portal of Central Electricity Authority (CEA) and CEA’s own past records, one is shocked to see that during June-July 2018, Idukki generated about 325 Million Units (MU) of power, which was below power generated during at least four years in just last decade: below that in 2008, 2012, 2014 and 2015. In 2014, the highest generation year for June-July, Idukki generated over 50% more than it generated in June July 2018. If Idukki had generated more power, that could have also help reduce water level.
So why did Idukki power not generate more power when so much water was available. National Power Portal[ii] provides the answer: one of the six 130 MW units of Idukki has been under shut down since Aug 1, 2017 for Renovation/ modernisation and another 130 MW unit is under shut down since June 26, 2018 for annual maintenance. Its of course a mystery why the second unit was taken out for annual maintenance during monsoon, when it could have been done in dry season. But the consequences of this actions are that Idukki produced less power and it also added to flood disaster misery of Kerala.
In fact, even before the SW monsoon set in this year, on May 31, 2018, Idukki’s live storage capacity was 25% full, much higher than normal and higher than previous year or average of last ten years. That also contributed to the dam filling up sooner. Why such high water storage before the onset of monsoon is a question that the Idukki managers will need to answer.
Kerala Rainfall As per IMD (India Meteorology Department) figures, till Aug 9, Kerala received 20% above normal rainfall. Idukki districts tops with 50% above normal rainfall and also highest rainfall among all districts of Kerala so far: 2433.5 mm. Palakkad (44%), Kottyam (36%) and Ernakulam (33%) are some other districts having high surplus rainfall. But it’s possibly the bouts of high intensity rainfall that has created the current situation.
In Conclusion Its clear that major storage dams of Kerala like Idukki and Idamalayar, by releasing water when Kerala is facing floods due to widespread heavy rainfall, are adding to the flood misery of Kerala. This could have been avoided if the dam operators had started releasing water in advance rather than waiting for dams to be filled up, when they have no alternative but to release water. Its also clear that there was sufficient time and relatively dry period when they could have released water, rather than when Kerala is facing floods. If the Idukki power unit that was taken out or operation from June 26, giving “Annual Maintenance” as reason was in stead taken for annual maintenance during drier summer months, that would have helped, particularly when one unit is already out for renovation. If the water level in Idukki was lower before the onset of monsoon, it would have helped. CWC’s absence in flood forecasting is also additional handicap.
All this requires action. Possibly one of the first things, post current phase of rescue and emergency, that Kerala govt can do is to institute an independent inquiry into these issues, so that such situations do not recur, when dams, in stead of helping moderate the floods, add to the flood misery.
Himanshu Thakkar, SANDRP (ht.sandrp@gmail.com)
SANDRP
Idukki dam shutter opened after 26 years in Kerala following heavy rain
9-8-2018
This is the first time that the incessant southwest monsoon, which has caused a series of floods and landslides in several districts of the state, has forced the dam sluice gates to be opened.
In a historic move, the Kerala State Electricity Board (KSEB) opened one of the five shutters of the Cheruthoni dam on the Idukki reservoir as the water level inched up to 2398.99 ft. The shutters of one of the largest arch dams in Asia are being opened after 26 years. The maximum storage level in the reservoir is 2403 ft.
The dam, commissioned in 1975, has been opened only twice, both during the northeast monsoon in the months of October-November. This is the first time that the incessant southwest monsoon, which has caused a series of floods and landslides in several districts of the state, has forced the dam sluice gates to be opened.
The Kerala State Disaster Management Authority (KSDMA) made it clear that the middle shutter of the dam has been opened as part of a trial run for the next four hours to gauge the water level in the reservoir. The middle shutter has been lifted 50 cms, releasing up to 50,000 litres of water per second. The other shutters will be lifted only if a need arises. The SDMA said people living in a radius of 100 m along the banks of the Periyar river and in the low-lying areas must exercise caution as the shutter is being opened.
The water being released from the Idukki reservoir will travel through the Cheruthoni river to meet the Periyar after a distance of one kilometre. The river then passes by Thadambiyad, Karimban, Bhoothathankettu and Perumbavoor to reach Aluva. The Periyar drains further into the Arabian Sea.
-Indian Express
Seasonal water level in Idukki dam the highest ever
17/7/2018
Level reaches 69.3% of the total reservoir capacity
The Idukki dam clocked a history high recording with a seasonal water level of 2,375.52 ft on Tuesday.
It was 69.3 % of the total reservoir capacity. There was a rise of over 4 ft in the water level from the previous day. The water level on the same day last year was 2,316.98 ft, which was 20.92 % of its total capacity.
The main tributary, the Periyar continued to be in spate despite a lull in rainfall on Tuesday. On July 17, 1985, the water level reached 2,374.1 ft, which was the highest seasonal water level till now. On the same day in 1976, the water level reached 2,300 ft. The catchment area on Tuesday recorded a rainfall of 73.2 mm.
The water level in the Mullaperiyar dam steadily rose to131.2 ft on Tuesday. For the past four days there was an increase of two feet per day.
The Mullaperiyar sub-committee under the supervisory committee appointed by the Supreme Court is scheduled to visit the dam on Wednesday in the wake of the increasing water level. There was heavy inflow of water in to the dam and if the situation continued, the water level will reach the maximum level of 142 ft in a few days.
- The Hindu
With the catchment areas of the dam receiving heavy rainfall over the past several days, the water level in the dam has been increasing considerably.
31/7/2018
IDUKKI: An orange alert is out, with the District Collector Jeevan Babu K issuing it at 9.10 pm on Monday. Should the rain remain incessant, people settled downstream of Cheruthoni Dam — particularly in the Thadiyampadu, Karimban and Injivarakkuth areas on the banks of the Cheruthoni River — have two or three days to move out of their homes and shelters.
While clarifying there was no need to panic, the district administration issued the alert after the water level crossed 2395 ft. With the catchment areas of the dam receiving heavy rainfall over the past several days, the water level in the dam has been increasing considerably.“The water level is inching towards the full reservoir mark,” said a Kerala State Electricity Board (KSEB) officer.
“It has now crossed 2,395 ft and is going up by 0.06 to 0.08 ft every two hours. The rise in the level by two more feet will lead to declaration of the Red Alert. The full reservoir level is 2,403 ft, but we will start opening the shutters when the water level goes above 2,397 ft. If the inflow into the reservoir continues at the current rate, we may have to open the shutters within two days.”
Water will be released only during the day: Idukki Collector
The district administration said that four relief camps have already been set up to accommodate people in case of evacuation. “Of the 200 families living downstream, preparations are under way to evacuate 40 of them to relief camps,” Jeevan Babu said. “A control room has been functioning from Sunday night and red alert message signifying the extreme gravity of the situation will be issued 24 hours before the opening of the shutters.”
The Collector has also assured people living downstream that water will be released only during the day time, with all necessary precautionary measures having been taken to ensure security.
People have been restrained from visiting the area to see the opening of the Cheruthoni shutters. As estimated, the opening of the shutters at Cheruthoni — part of the Idukki dam project — will lead to water gushing to the Lower Periyar Dam and on to the Bhoothathankettu Dam. From there, water will flow through Periyar along Kalady and Aluva before merging with the Arabian Sea. Water is estimated to take nearly six hours to reach the Arabian Sea once the Cheruthoni shutters are opened.
If the shutters were to be opened, it will be the first time during the southwest monsoon since the construction of the dam in 1973. Twice in the past, the shutters had to be opened. But they were during the northeast monsoon (October to December).
The first instance was in 1981 (when the shutters were repeatedly opened and shut between October 29 and November 13) and the second time in 1992 (when they were kept open for 12 days from October 12 to 23). On both occasions, the water level in the dam touched the brim only when the storage built up during the southwest monsoon (June to September) was augmented by the inflow received following heavy downpour in the northeast monsoon.
The Idukki district administration has issued warning notices to the households and shops located downstream of the Cheruthoni Dam.
Many people who have cultivated crops on their agricultural land near the banks of the Cheruthoni river have started harvesting them, even though they have not reached maturity. Others have started to pack up their essentials to leave their houses, in case the red alert is issued.
2,395-ft mark was breached on Monday forcing the District Collector to issue orange alert. 135.80 ft is the new water level in the Mullaperiyar dam after it came down from Saturday’s 135.95 ft
Shutters of Neyyar dam opened
T’Puram: The shutters of the Neyyar dam were opened following heavy inflow of water into the reservoir from its catchment area. The four shutters of the dam were opened slightly by night. The full-reservoir level of the Neyyar dam is 84.75 metres. People living on the banks of the river downstream from the dam have been alerted.
‘Don’t fall for fake news on Idukki dam’
Kochi: A high-level meeting held in Kochi on Wednesday has urged public to not to believe fake news being spread in connection with the opening of shutters of Idukki and Idamalayar dams. MLAs, who attended the meeting held at Kakkanad, demanded cyber cell to take legal action against those who spread fake news through social media.
‘200 families will have to be evacuated’
Idukki: Terming the orange alert as just a standard operation procedure which is part of the dam safety protocol, District Collector K Jeevan Babu said there is no cause for panic. Allaying fears, he said people do not have to be evacuated soon after the alert. “When there occurs an emergency to evacuate people, it will be done only after alerting them and they will be shifted to the safest locations,” he said. According to him, only four relief camps need to be opened — in the Vazhathope, Mariyapuram, Kanjikkuzhy and Vathikkudy panchayats — near Cheruthoni. “The flood will affect 22 families in the Vazhathope panchayat alone. A total of 200 families will have to be evacuated, out of which 40 families will be evacuated in the initial phase,” he said. Those interested in moving to their relative’s houses will be allowed to go and the rest will be given refuge in the relief camps. Jeevan Babu said the district administration has not yet decided the date of the trial run and this will be done only after informing the people 12 hours before opening the shutters.
Water level comes down in Mullaperiyar dam
Idukki: Much to the relief of the people residing in the downstream of Mullaperiyar, the water level in the dam has come down to 135.80 ft on Monday compared to Saturday’s mark, which was 135.95 ft. The water level at the dam on Sunday was at 135.90 ft. The dam authorities attributed the decrease in the water level to the reduction in the rainfall in the catchment areas of the dam. The catchment areas of the dam, Periyar and Thekkady, received 13.2 and 1.2 mm rainfall, respectively on Monday. Similarly, the inflow of water into the dam has also shown a decreasing trend. The inflow into the dam which was recorded at 2,008.9 cubic feet on Sunday decreased to 1,807 cubic feet on Monday. Even as Tamil Nadu has reduced the intake of water from the dam to 2,100 cubic ft from 2,300 cubic ft, the dam safety officers told ‘Express’ that the water level in the dam was steady at 135.80 ft.
-New Indian express
13/9/2017
Still it is only 47.85% of the total reservoir level
For the first time since the southwest monsoon started, water level in the Idukki dam has crossed the last year’s storage level. The water level on Wednesday was 2,352.36 ft compared to last year’s level of 2,351.24 ft. this time.
This is 47.85% of the total reservoir level, which stood at 46.9 percentage on the same day last year.
According to an official at the Dam Monitoring and Search Station, Vazhathoppe, though there was no rainfall recorded on the catchment area for the past two days, there was good inflow through the main tributary, the Periyar.
The water level was lower than the previous year with poor rainfall during the initial period of the monsoon. The power generation at the Moolamattom Power House also remained at a low. The power generation on Wednesday was 5.32 m.u., which was 4.45 m.u. the previous day. (On Monday and Sunday it was 2.50 and 2.41 m.u respectively).
Though the water level still remained below the average level of the season, the minimum water level prior to the beginning of this monsoon was at a low of 2,299 ft. recorded on June 23, 2017. The official said that though the minimum water level normally would be above 2,300 ft, it fell further prior to this monsoon causing concern on a poor storage in the dam.
The generators and other equipment in the power house are undergoing a revamp reducing the generation level.
- The Hindu
Idukki dam water level reaches dismal depths
30/7/2017
Reservoir had only 22.68% of its total capacity on Saturday
With poor rainfall in the catchment areas, the water level of the Idukki dam is at one of its lowest levels in recent years.
The water level on Saturday was 2,319.80 ft, which is only 22.68% of the total reservoir level.
An official of the Dam Monitoring and Research Station, Vazhathoppe, said on Saturday that the percentage of water in the dam on the same day last year was 43.24.
Inflow dips
The inflow of water into the dam which was copious with the advent of the southwest monsoon has dipped, resulting in low power generation at the Moolamattom power house.
On Saturday, the catchment area recorded a rainfall of 29 mm and the power production was just 2.7 million units.
The official said that power generation was one of the lowest of this year.
The minimum water level of the season prior to the southwest monsoon was also low this year, the official said. Poor northeast monsoon contributed to the present situation.
The maximum water level of last year was 2,352 ft, recorded in September 2016. The Idukki dam is the largest contributor to power generated in the State.
Electricity Minister M.M. Mani told The Hindu on Saturday that the government had not considered imposing power cut so far.
However, load-shedding would be considered if the situation warranted, he said.
It would be done only after informing the public, the Minister said.
He denied that there was unannounced load-shedding in the State.
There was a problem regarding bringing of power from outside the State, Mr. Mani said, adding that electric lines needed to be strengthened.
The State generated only 30% of the power required here, that too when the hydroelectric projects operate in full swing. Upgrade of the transmission sector and reduction of transmission losses are prime concerns. If the situation persisted, the government might have to consider power cut. The situation on the power front was precarious, he said.
-the Hindu
23/9/2013
With the increase in water level in the Idukki dam showing a declining trend, the Kerala State Electricity Board on Sunday ruled out the possibility of opening the Cheruthoni dam for three days.
K.K. Karuppankutty, KSEB (Dam Safety) Chief Engineer, told the media after visiting the Cheruthoni and Idukki dams that the inflow of water had declined following a fall in rainfall in the catchment areas, which was just 1.2 mm till 24 hours on Wednesday. The water level had been remaining almost constant at 2,401.68 ft since Sunday evening, said an official of the control room atop the Cheruthoni dam, which monitors the water level every hour.
Power generation at the Moolamattom power house was at the maximum level of 18.17 million unit.
The KSEB was against discharging water as it may cause flooding in downstream areas. Mr. Karuppankutty said there was no need for opening the dam as the water level was remaining constant.
“Only in case of a heavy rainfall and increased inflow, the opening of the dam needs to be considered,” he said adding that compared to the water level on Saturday evening, the rate of increase was only 0.18 ft.
However, the district administration is on alert with the water level at the dam almost at the brim in September itself.
The dam shutters had been opened in 1981 and 1992 (during October) when the water level was 2,402.17 ft and 2,401.44 ft respectively. Though a relieved atmosphere prevailed here on Sunday, District Collector Ajit Patil told The Hindu that the administration was on alert and the control rooms at the seven villages and at the two taluk offices downstream would continue to function. He said the officials had been ordered to keep vigil though the dam need not be opened for three days.
-the hindu
Countdown to Idukki dam opening begins
20/9/2013
Water level rising; the public and officials put on alert
All power generators below the penstock tunnels leading from Kerala’s largest hydel reservoir in Idukki are working round the clock in what appears to be a losing battle to prevent the opening of the dam shutters.
“The water level is inching towards the full reservoir mark,” K.K. Karuppankutty, Chief Engineer, Dam Safety, Kerala State Electricity Board (KSEB), told The Hindu here on Thursday.
“The water level has now reached 2,400.23 ft and it is going up by 0.02 ft every hour. The full reservoir level is 2,403 ft, but we will start opening the shutters when the water level goes above 2,402.5 ft. If the inflow into the reservoir continues at the present rate, in about 113 hours from now, we may have to open the shutters,” Mr. Karuppankutty said around 4 p.m.
The catchments of the reservoir have been receiving good rain since September 12, and the meteorological indications on Thursday were in favour of continued rain in the High Ranges of the State for at least three more days, which will mean heavy inflow into the reservoir for at least five or six days.
Meeting held
Electricity Minister Aryadan Mohammed called a meeting of top officials on Thursday to organise preparations for opening the dam shutters.
The meeting assessed that even if the storage of water was utilised at the maximum possible level by operating all the turbines generating power, the shutters of the dam might have to be opened anytime between September 22 and 24.
Top officials would proceed to the dam site from the KSEB headquarters on Saturday to monitor and oversee the preparations.
If the shutters were to be opened, it will be the first time during the southwest monsoon since the construction of the dam in 1973.
Twice in the past, the shutters had to be opened, but during the northeast monsoon (October to December) on both occasions.
The first time was in 1981 (when the shutters were repeatedly opened and shut between October 29 and November 13) and the second time was in 1992 (when they were kept open for 12 days from October 12 to 23). On both occasions, the water level in the dam touched the brim only when the storage built up during the southwest monsoon (June to September) was augmented by the inflow received immediately afterwards following heavy downpour early in the northeast monsoon.
Thus, the difference now is that the Idukki reservoir is reaching its full level with inflow received only during the southwest monsoon. As on Thursday, the State has received 31 per cent excess rainfall during the season.
Numerical weather predication models of the Chennai regional meteorological centre on Thursday favoured the possibility of widespread and heavy rain in Kerala during the next three days. An offshore trough was in position at mean sea level from the Karnataka coast to the Kerala coast and the southwest monsoon flow had quickened over the State, drawn by a low-pressure system over northwest Bay of Bengal.
Warning issued
Kattappana Correspondent adds:
The Idukki district administration has issued a warning that the dam will be opened on Saturday or Sunday.
District Collector Ajit Patil said the tahsildars and the village officers had been instructed to shift people living in the downstream areas in case of an emergency.
He said a public warning would be issued prior to the opening of the dam shutters and separate 24-hour control rooms had been opened at the taluk and the village levels. Mr. Patil said all precautionary measures had been taken, and the KSEB control room (ph: 9496 011974) was alerting various departments to the water level every hour.
An official of the control room said that though the rain had decreased slightly on Thursday, inflow was at a high level.
The phone numbers of various control rooms are: (04868) 275 293 (Thankamany); (04862) 230 888 (Upputhodu); (04868) 262 902 (Konnathady); (04868) 237 865 (Udumbanchola taluk); (04868) 260 302 (Vathikudy); (04862) 232 393 (Idukki); (04862) 239 582 (Kanjikuzhy); (04864) 276 201 (Vellathooval); (04864) 222002 (Mannakandam); and (04862) 222 098 (Thodupuzha taluk).
-the Hindu
Rise in water level in Idukki dam
19-9-2013
The water level in the Idukki reservoir rose steadily on Wednesday, by 1 ft over the previous day to reach 2,399.30 ft. The full reservoir level (FRL) is 2,403 ft.
On Tuesday, the increase in level was .5 ft and if the inflow continued at the same level through the main tributary, Periyar, the dam would be opened within a week. The increased level of water drawn by Tamil Nadu from the Mullaperiyar dam was a key factor in keeping the level in Idukki dam almost static till it rained heavily in the catchment areas in the past four days. Power generation at the Moolamattom power house was also raised to the maximum level to keep the water level under control. However, with the increased production level, there was high inflow of water causing a sudden spurt in the reservoir level.
The district administration has made preparations to open the dam shutters in case the water level rises above the FRL. Directions have been given to the village officers to take up evacuation on the downstream of the dam if the water level rose, District Collector Ajit Patil told The Hindu on Wednesday. He said there was no chance of a sudden water discharge as the water level in the Mullaperiyar dam was at a low. The water level there was 123 ft on Wednesday, also registering nearly .5 ft increase over the previous day’s water level.
Mr Patil said all precautionary measures had been taken. There was no need to panic as the increase in the water level was under control, he said adding that the people would be informed in advance if any decision was taken with regard to opening of the dam.
The average rainfall recorded in the district on Wednesday was 64.34 mm with the Peerumade taluk registering the highest rainfall of 123 mm. Udumpanchola recorded the lowest rainfall of 25.8 mm. Devikulam taluk, 70.2 mm. and Thodupuzha 32.7 mm.
-The Hindu
12/10/1992 The Assistant engineer in-charge of opening the dam recalls the tense situation. Water Level was 2400.7 feet. Slow opening in morning 9 am more opening in night.
Explained Snippets: How intense rainfall brought in more water than Kerala’s dams could hold
Kerala floods: 1.16 bn cubic m space available in dams, 2.19 bn cubic m inflow in 3 days
A Central Water Commission (CWC) report on the Kerala floods, released Monday, explains how three days of intense rainfall (August 15-17, 414 mm) brought in more water than the state’s dams could accommodate, making it necessary to release water. From the catchment tapped by the dams, excluding barrages, the report estimates that the runoff generated during the three-day period was 2.19 billion cubic metres (BCM), out of a total runoff of 12 BCM for the state. “The total live storage of Kerala is about 5.8 BCM. Even with 20 per cent of the live storage availability on 14 August 2018, the available flood moderation extent would have been only 1.16 BCM against the estimated inflow of 2.19 BCM,” the report states. “It shows that in any case, it was essential to make releases from reservoirs.”
The report refers to two previous floods, in 1924 and 1961. During July 16-18, 1924, heavy rainfall occurred on almost entire Kerala, causing heavy loss of life and property. “The centre of the 1-day and 2-day rainstorm was located at Devikulam in Kerala which recorded 484 mm and 751 mm of rainfall respectively. The centre of 3-day rainstorm was located at Munnar in Kerala which recorded a rainfall of 897 mm in 3 days,” says the report, which also compares the amount of rainfall during the three peak days of 1924 and the three peak days of 2018.
In 1961, floods were unusually heavy both in duration and in intensity of precipitation, with the monsoon getting violent towards the last week of June and in the early days of August. The average rainfall was 56 per cent above normal.
-Indian Express
As Kerala Drowns We Look for the Machine and the Human in Early Warning Systems
By Prof. Amita Singh
Chairperson,
Special Centre for Disaster Research, JNU Professor Law
& Governance
August 20, 2018
Kerala floods not
for the first time
Kerala floods resurfaced after 1924 and have again
caught unawares the modern technology systems boastful of their might
and their superior grip. Just as the designer of the mighty ship
Titanic, Sir Thomas Andrews had declared that even the God cannot
sink Titanic is a mathematical certainty, so did the Kerala
government stretched over the incredible God’s own country! Under
the prosperity of development lie many untold stories about the
rising population of the elderly to almost 12.6% of the states total
population which is the highest in the country. The districts worst
affected by the floods such as Ernakulum, Kottayam, Thrissur and
Malappuram are also the ones with substantially higher number of
elderly who are living alone in loneliness and isolation. The data on
how many were able to survive the calamity is yet to surface. The
above 65 population of Kerala is rising by 2.3% per annum and is
likely to shake off welfare policies in old age homes, palliative or
end-of-life care facilities as compared to schools, factories and
other employment generation infrastructure. Now the worry is
primarily about who will build them back? This and many more
instances prove that the loss is irreparable for many more decades to
come.
Was Kerala Prepared?
Was Kerala not prepared despite having to its
credit the country’s first State Disaster Management Authority
immediately after the Disaster Management Act of 2005? Since the
Hyogo Declaration and its follow up by the Sendai Framework for
Disaster Risk Reduction, Kerala was found completely lacking in
even the basic preparedness that could have substantially reduced the
whopping losses and damages which even by most conservative estimates
currently stand beyond Rs.20,000 crores (Kerala GDP 7.73 L
crore).This will increase as water recedes. Almost 12 of the 14
districts in Kerala reeled under torrential rains, crop worth 3.42
billion rupees (US$49.65 million), across 26,824 hectares had been
destroyed by rains since their onset on May 29 and 31,000 people were
forced to take shelter in rescue camps yet the Chief of the Kerala
SDMA P.H.Kurian maintained that the rains have eased. The state’s
high investment in the early warning systems was neither used nor
referred to.
As the administrative machinery which was expected
to do the following ie;
- map in advance the most vulnerable zones,
- streamline the most appropriate rescue operations,
- mark evacuation safety points,
- storage godowns for basic necessity foods and medicines,
- shelter platforms for animals and
- fast track GIS and meteorological possibilities of disasters through dams and landslides etc.
The administration was found having done nothing
of the above. Interestingly, the early warning systems (EWS)
forecasting was installed but overlooked wherever it could have been
available. Both the human as well as the instrumental equipment side
of the device was ill prepared.
EWS is a mechanical system where technology takes
over or performs the task of appropriate identification, detection
and mobilization of action. In earlier eras of human history early
warnings were community generated, they came as a natural
corollary to indigenous wisdom where wise community leaders could
predict disasters through the movement of clouds, colours of the sky,
behavior of animals and silence of trees.These leaders used to move
their tribes and animals to safer places whenever they sensed
possibilities of hurricanes, tornadoes or tsunamis in their regions.
The grand old woman or man of the community were repositories of
knowledge about ecological history and interdependence of ecosystems.
This wisdom was passed down to newer generations and communities were
able to maintain their resilience to disasters. As community habitats
were disrupted through deforestation, mining, infrastructure
expansion into wilderness zones, mobile and high frequency
electromagnetic and radio waves disrupting environmental sounds from
skies to the ocean bed, natural signals were obstructed, and
resilience weakened. In a modern world much of the older community
resource which helped them resist fatal calamities are being lost
such as mangroves, bamboos, house building materials, particular tree
leaves to contain forest fires or grasses to produce smoke which
prevented the spread of epidemics. The community knowledge lost due
to environmental degradation and land scape changes is beyond the
comprehension of the current generation yet it is difficult to return
to the serenity where community based EWS worked. So, the laboratory
based EWS were pulled in to fill the loss. These EWS attempted to
absorb as much meteorological and geospatial information which the
instrument could identify and capture. These instruments obtained
sophisticated ability to work through remote sensing and satellite
imagery and make predictions which were the closest approximation to
real threat.
Who would trust EWS Warnings?
The EWS succeeded in warning people but the trust
deficit on one hand and governance deficits on the other hand failed
appropriate response to the warning. This suggests that EWS can warn
before the disaster but what should be done after the warning is
received or ‘subsequent action’ requires a translation of this
scientific information into readable and understandable warnings and
alerts to be immediately transferred to the field administrative
agencies. The field agencies are expected to spring into required
action for preparedness, rescue and public engagement with local
communities, support institutions and rehabilitation centres. Another
important factor is the emphasis that EWS is a responsibility of
administrative agencies towards preparedness or advance planning
based on warnings on impending disasters. Say for example, if a
particular zone is landslide affected and landslides occur mostly
during rains then a special preparation to make communities safer
should have been done in advance. As I am writing this article,
India’s most scenic and most highly rated state in human
development index ‘Kerala’ is reeling under devastating floods
which is seen as a return of the most destructive 1924 floods in the
history of the state. The Indian Meteorological Department (IMD)
indicated a deviation from the normal 1,606.05 mm rainfall but in a
week this normal rainfall crossed an increase of 257% as per the
records. Some of the most visited tourist destinations of
Athirapally, Ponmudi and Munnar witnessed unprecedented
destruction.The question arises why this advanced and progressive
state did not have any EWS system or if it had why were they not
helpful?
Warnings ignored by Administration:
Was it the deciphering of information or the
intention? Kerala as the most developed state in India was
systematically warned by the Office of the Comptroller and Auditor
General (CAG) that despite its huge investment of 2.34 Crores in the
LBEWS the state neglected the installations and repairs of
installed EWS due to which 289 out of 351 EWSs were found
non-functional. The state was also quick to install very high
frequency radio based communication for enforcing an effective
warning even in times when telephones and other devices of
communications stop working.This was undertaken in 379 locations and
the installing company Linkwell Electronic Private Ltd. was
accountable for its operational maintenance. Interestingly, despite
the fact that most of the instruments failed to work the government
did not impose any liquidated damages on the firm but on the top of
it overseeing the lapse, all balance payments were made to the firm.
The CAG report also mentions that EWS failed due to administrative
inability to disseminate warnings to communities and also lack of
trained personnel to operate the system.
Another EWS related issue which catches attention
from the Kerala story is about the knowledge system and a leadership
specific to the ecosystem of each state. The state has 44 rivers and
42 dams and some dams have very high reservoir capacity. But is this
knowledge enough? To decipher scientific warnings issued from
laboratories one need to be grounded in the local knowledge system
and may not be a transient traveler on an administrative posting.
When the adjoining state of Tamil Nadu issued the first warning alert
to Kerala about excess water from Periyar river’s Mullapperiyar dam
likely to flow down to the Kerala’s Iduki dam, it was dismissed as
unnecessary panic by the KSEB Chairman and Managing director N S
Pillai as well as the overconfident Power Minister M.M.Mani. Finally
they opened the gate with a huge surge of flash flood about which
most people and even district administrators were caught unawares. It
is also alleged by local people that the shutters of another dam of
Banasursagar were opened without giving any intimation even to
district authorities.
The Secretary General of the World Meteorological
Organization Michael Jarraud suggests, ‘ Disaster Prevention and
mitigation are essential to sustainable development…..the challenge
for countries is therefore to empower each community to apply these
tools optimally through networking and partnerships’. In the same
gathering on Early Warning Systems the President William J.Clinton
went further ahead of Jarraud to declare that ‘if we want an
effective early warning systems we must work together government to
government, federal to local officials, scientists with policy
makers, legislators with teachers and community leaders.’[1].
Conclusion:
Therefore, EWS is just a bit of technology and
largely a tool of governance which should be brought together in a
network all stakeholders much prior to the disaster. This
preparedness question around the use of EWSs is much dependent on the
capabilities and shortcomings of administrative systems and the
leader on the steering wheel. It is also clearer to ascertain that a
participatory local governance can play a major role in building
trust, overcoming gaps between science and non-science
administrative institutions and local community institutions and this
is the test which fails most governments in implementing early
warnings. With this understanding the present paper looks at the
nature, progress and drawbacks of EWS systems in some key areas in
Asia.
19/8/2018
Flood forecast not
done by CWC as ‘Kerala didn’t put in request’
In April 2018, CWC’s manual termed ‘Standard Operating Procedure for Flood Forecasting’ listed 19 major interstate rivers that were under monitoring.
Kerala was not under the Central Water Commission’s radar for flood forecasting this year. A CWC official in the flood forecast monitoring department said the reason was because Kerala did not put in a request before the monsoons began and the agency largely monitors inter-state basins.Further, since Friday, all of CWC’s hydrological observation gauges in Kerala have either gone under water or the agency has lost contact with them, the official said. “Most of our sites are under water since Friday, either submerged by the rising water or our communication has been lost. Gauges are one-two metres above the HFL (highest flood line) and they are all submerged now.”
In April 2018, CWC’s manual termed ‘Standard Operating Procedure for Flood Forecasting’ listed 19 major interstate rivers that were under monitoring. In all, it noted that flood forecasts were being issued by the CWC at 226 stations across these basins. The document listed 24 states in which flood forecasting stations were operational. The CWC issues a level forecast and an inflow forecast.
But to get on the list, the official said, a formal request is required from the state. “The request is often made in the case of interstate rivers since one state might be interested in knowing about the situation in a neighbouring state with which it shares a river. However… Kerala… largely has intra-state rivers that start from Western Ghats,” the official said.
Mullaperiyar is the only exception, the official said, but it was monitored by a separate committee.
The reservoir levels (as percentage of full capacity) on 17th July, 2018 was more than double of 2017 and for last 10 year average.
On 17th August, 2018 : 35 of 38 dams are opened.
WHY?
The reservoir levels (as percentage of full capacity) 2018 2017 Average
Idamalayar 99 37 54
Idukki 93 30 48
Periyar 100 14 46
Was the attempt to save 100 crores for electricity worth it?
Why was the margin for shock absorption of heavy rain not kept?
Note: 10 million cubic feet of water flow out when shutters are opened and the corresponding electricity power generating capacity is 220 crores worth. Three dams at idukki were built with cost of 110 crore.
The Kerala catastrophe - Could timely action from the govt have saved lives?
More than 160 people have died and lakhs left homeless.17/8/18
More than 160 people have died and lakhs left homeless as rain continues to batter Kerala, which is reeling under the worst flood it has witnessed since 1924.
Even as the Armed Forces and the National Disaster Response Force are joined by the local fishermen in rescue and relief operations, the fate of millions hang in the balance — according to reports, 2,23,000 people have been accommodated in 1 ,568 relief camps across the state, road and rail transport are completely suspended in several areas, hospitals battle a lack of liquid oxygen and diesel, and crops and property worth Rs8,000 crore have been damaged.
But rain fury alone is not responsible for the state’s miseries.
For the first time ever, shutters of 35 of Kerala’s 39 dams were opened, within days of each other. At a time when the state was already receiving more rainfall than usual, the excess water from the dams flooded the rivers. The adjoining areas were inundated, houses and roads submerged in water, residents forced to flee.
What is more, according to some locals, proper warnings were not given to them about the sluice gates opening, leaving them with little time to gather their belongings and move to safety.
Why were the dams not opened well in time, before the rains got worse? Why did authorities wait for water levels to reach the danger mark, necessitating the opening of all the dam gates around the same time?
Even as the decision to open the gates was being delayed, why were people in the nearby areas not moved to safety?
These are some of the questions the Pinarayi Vijayan government needs to answer.
An article in Firstpost quotes Murali Thummarukudy, chief of Disaster Risk Reduction in the United Nations Environment Programme (UNEP), as saying: "Sitting at Geneva, I had on June 14 cautioned that the reservoirs will be filled by July. I had made the prediction based on the experience in Thailand and Pakistan. Unfortunately, our engineers did not foresee this.”
Residents, too, have been quoted as saying that Idamalayar dam in Ernakulam and Banasara Sagar dam in Wayanad were opened without giving them adequate warning, and all the five shutters of the Cheruthoni dam were opened together, instead of opening them phase-wise with simultaneous evacuation of people.
Firstpost has quoted dam safety expert N Sasidharan as saying: “The authorities waited till the water level in the Idamalayar reservoir reached its capacity of 169 feet. If it was opened when the water level reached 165 feet, it would not have necessitated the evacuation of many people in the downstream areas. This is the result of poor planning by the disaster management authority.”
The same complaint has been made about the Idukki dam too, opened for the first time since 1992. Warnings about Idukki were being raised as early as July 31. But that time, state water resources minister Mathew T Thomas had said there was no need for even a trial run of opening the dam’s sluice gates, as the “water level was rising only by 0.02 feet an hour”.
Warnings about water levels in Idukki were being raised as early as July 31. (Photo: PTI)
The South Asia Network on Dams, Rivers and People (SANDRP) has cited how the water level in Idukki rose faster because two of its six turbines, that use water for power generation, were non-functional. One of these was shut down on June 26 for annual maintenance. What was the point of shutting down a turbine for maintenance just before the monsoon?
Also, as late as on August 17, Kerala and Tamil Nadu were arguing over the Mullaperiyar Dam, which is managed by Tamil Nadu.
Clearly, as disaster surged close, the state government was caught napping. Contrast this with Odisha in 2013, when, during the Cyclone Phailin, timely warnings and evacuation of people had ensured that the loss of lives was minimised — 38, as compared with the 167 in Kerala already. A report by the United Nations Environment Programme’s Global Environment Alert Service had said about the Odisha government: “Government cooperation, preparedness at the community level, early warning communication and lessons learned from Cyclone 05B [in 1999], contributed to the successful evacuation operation, effective preparation activities and impact mitigation.”
If resource-strapped Odisha could have prepared itself so well for a natural disaster, could not richer, more developed Kerala have done the same?
Even apart from this, there is a lot the Kerala government needs to answer for.
In 2011, the Gadgil Committee made several suggestions to Kerala to conserve the ecologically fragile Western Ghats. The recommendations included restrictions on mining and quarrying, on use of land for non-forest purposes, and on the unabated proliferation of high-rise buildings. The government had rejected the report.
Now, environmentalists are pointing out that widespread and uncontrolled quarrying has led to the mudslides the state is witnessing, which are responsible for the most number of deaths in these floods.
Once the flood and fury recede, there are many lessons the government of Kerala needs to take from this disaster.
-DailyO
Kerala Floods: What Led to Deluge That Reminded People of The Great Flood of 1999
For the first time in history, Kerala has opened 35 of its 39 dams, including Mullaperiyar, Cheruthoni, part of Idukki reservoir and Idamalayar, wreaking havoc in the downstream areas.
17/8/2018
New Delhi:
Kerala is fighting to stay afloat in what is seen as the century’s
worst flood in the state. At least 167 people are dead and about two
crores affected by the deluge that destroyed more than Rs 8,000 cr
worth property since August 8.
All 14 districts of the state have been placed under red alert after the rise in flood waters in Periyar river due to the rains and opening of the shutters of all major dams.
All 14 districts of the state have been placed under red alert after the rise in flood waters in Periyar river due to the rains and opening of the shutters of all major dams.
For the first time
in history, Kerala has opened 35 of its 39 dams, including
Mullaperiyar, Cheruthoni, part of Idukki reservoir and Idamalayar,
wreaking havoc in the downstream areas.
The rail and road
connectivity has been severely hit. There have been more than 20
instances of roads being washed away due to severe flooding; railway
lines and more than a dozen stations are submerged; Kochi airport’s
runway remains inundated.
But what led to the
deluge that reminded people of "the Great Flood of
1999"?
Rainfall Pattern
According to the Indian Meteorological Department data, Kerala received 2,087.67 mm of rain from June 1 to August 15—a departure of nearly 30 per cent from the 3,368 mm water in 1924.
An analysis of the rainfall data from 1901 to 2016 by weather scientists suggest that the southwest monsoon has ‘dried’, that the monsoon is on a declining trend. After rising in 2013, the rainfall in state reduced in 2014 and hit a low in 2015 before slowly rising in 2016, 2017 and 2018, IMD data read.
Then why did Kerala Chief Minister Pinarayi remark on August 14 that “this is the worst monsoon disaster since 1924”?
Well, there is another trend, which suggests a rising rainfall quantity in the state in the past few years. There is low frequency but higher intensity, meaning the rainfall occurs for a short duration, however, the amount of precipitation is higher.
Poor Policy Decisions
Most of the regions impacted by the floods were classified as ecologically-sensitive zones (ESZs) by the Western Ghats Ecology Expert Panel (WGEEP). The report was made public by a team headed by Madhav Gadgil, ecologist and founder of the Centre for Ecological Sciences at the Indian Institute of Science, Bengaluru.
According to environmentalists who were part of the research, the committee’s recommendations were strong enough to protect the sensitive Western Ghat region. The committee had suggested to classify 140,000 kilometres of the Western Ghats in the three zones as per the requirement of environmental protection in the areas. In many areas, the committee recommended restrictions on mining and quarrying, use of land for non-forest purposes and construction of high rise buildings.
However, the report, which was submitted to the Kerala government in 2011, was subsequently rejected and none of its recommendations were adapted by the government.
Many environmentalists have also pointed fingers at the extensive quarrying as the major reasons for the recent calamity, which has resulted in huge landslides — majority of the human casualties have been caused by these landslides.
A recent study conducted by scientists TV Sajeev and CJ Alex of the Kerala Forest Research Institute found that there were 5,924 big, medium and small quarries in Kerala.
Earlier, the Kerala High Court has said that quarrying in lands included in reserve forest but assigned for dwelling or cultivation should be banned altogether or strictly regulated.
“Quarrying activities should not be encouraged as it will cause permanent damage to the area,” the court had said.
Decrease In Forest Cover
A study by Indian Institute of Science (IISc), Bengaluru, found out that between 1973 and 2016, Kerala lost 906,440 hectares (9064.4 sq.km) of forest land. As the main reason for floods in Kerala remains the unusual rainfall pattern, this loss in forest cover, along with massive urbanisation may have led to several undesirable conditions, affecting the rainfall pattern. This loss of forest cover, many ecologists say, resulted in flash floods in past as well.
The effects of this were witnessed in Idukki and Wayanad, the two districts that bore the heavy brunt of the flood fury. Both the districts have the highest forest cover in the state. However, between 2011 and 2016 Idukki lost 20.13 per cent of its green cover, while Wayanad reported a loss of 11 per cent.
The other negative effect of decreasing forest cover in Kerala is the soil erosion it causes, which later settles in the dam reservoirs. The eroded topsoil can facilitate silting in dam reservoirs which could count towards an average reduction of 22% in the state’s dam storage levels, the IISc study said.
Rainfall Pattern
According to the Indian Meteorological Department data, Kerala received 2,087.67 mm of rain from June 1 to August 15—a departure of nearly 30 per cent from the 3,368 mm water in 1924.
An analysis of the rainfall data from 1901 to 2016 by weather scientists suggest that the southwest monsoon has ‘dried’, that the monsoon is on a declining trend. After rising in 2013, the rainfall in state reduced in 2014 and hit a low in 2015 before slowly rising in 2016, 2017 and 2018, IMD data read.
Then why did Kerala Chief Minister Pinarayi remark on August 14 that “this is the worst monsoon disaster since 1924”?
Well, there is another trend, which suggests a rising rainfall quantity in the state in the past few years. There is low frequency but higher intensity, meaning the rainfall occurs for a short duration, however, the amount of precipitation is higher.
Poor Policy Decisions
Most of the regions impacted by the floods were classified as ecologically-sensitive zones (ESZs) by the Western Ghats Ecology Expert Panel (WGEEP). The report was made public by a team headed by Madhav Gadgil, ecologist and founder of the Centre for Ecological Sciences at the Indian Institute of Science, Bengaluru.
According to environmentalists who were part of the research, the committee’s recommendations were strong enough to protect the sensitive Western Ghat region. The committee had suggested to classify 140,000 kilometres of the Western Ghats in the three zones as per the requirement of environmental protection in the areas. In many areas, the committee recommended restrictions on mining and quarrying, use of land for non-forest purposes and construction of high rise buildings.
However, the report, which was submitted to the Kerala government in 2011, was subsequently rejected and none of its recommendations were adapted by the government.
Many environmentalists have also pointed fingers at the extensive quarrying as the major reasons for the recent calamity, which has resulted in huge landslides — majority of the human casualties have been caused by these landslides.
A recent study conducted by scientists TV Sajeev and CJ Alex of the Kerala Forest Research Institute found that there were 5,924 big, medium and small quarries in Kerala.
Earlier, the Kerala High Court has said that quarrying in lands included in reserve forest but assigned for dwelling or cultivation should be banned altogether or strictly regulated.
“Quarrying activities should not be encouraged as it will cause permanent damage to the area,” the court had said.
Decrease In Forest Cover
A study by Indian Institute of Science (IISc), Bengaluru, found out that between 1973 and 2016, Kerala lost 906,440 hectares (9064.4 sq.km) of forest land. As the main reason for floods in Kerala remains the unusual rainfall pattern, this loss in forest cover, along with massive urbanisation may have led to several undesirable conditions, affecting the rainfall pattern. This loss of forest cover, many ecologists say, resulted in flash floods in past as well.
The effects of this were witnessed in Idukki and Wayanad, the two districts that bore the heavy brunt of the flood fury. Both the districts have the highest forest cover in the state. However, between 2011 and 2016 Idukki lost 20.13 per cent of its green cover, while Wayanad reported a loss of 11 per cent.
The other negative effect of decreasing forest cover in Kerala is the soil erosion it causes, which later settles in the dam reservoirs. The eroded topsoil can facilitate silting in dam reservoirs which could count towards an average reduction of 22% in the state’s dam storage levels, the IISc study said.
12-8-2018
Kerala rains; Even after a discharge of 50 cubic metres per second, the reservoir has continued to rise, and the discharge will be increased to 100 cubic metres per second from 7 am Friday.
For only the third time since the Idukki dams system in Kerala was commissioned in 1975, one of the five shutters at Cheruthoni was opened Thursday (the earlier occasions were in 1981 and 1992) after water in the reservoir rose to 2,399.04 ft, precariously close to its full storage level of 2,403 ft. Even after a discharge of 50 cubic metres per second, the reservoir has continued to rise, and the discharge will be increased to 100 cubic metres per second from 7 am Friday.
Rain and reservoir
The lake sprawls across Kerala’s lifeline Periyar river, and was created by the arch dam of Idukki, and the smaller Cheruthoni and Kulamavu dams. Incessant rain since the onset of the monsoon has left Idukki and other reservoirs downstream brimming. While Kerala as a whole has received 15% excess rain, Idukki district got 41% excess until August 8.
Full and overflowing
The Idukki arch dam has no shutters. The Kulamavu dam has penstock pipes that carry water to an underground power station at Moolamattam 43 km away. The water from the reservoir is used to run six generators with a total installed capacity of 780 MW.
Shutters of Cheruthoni dam are opened when the dam reaches full reservoir level. At Panamkutty downstream from Cheruthoni, a tributary of the Periyar called Mudirapuzhayar joins the flow from the dam. At Kallarkutty on the Mudirapuzhayar stands a power generation dam with a storage of 457 ft above sea level — this dam is currently overflowing, boosting the flow in the Periyar. A little ahead stands the Lower Periyar dam, which, too, is overflowing.
Further on its journey towards the sea, the Periyar is joined by a tributary called Edamalayar, which has a dam by the same name. The shutters of Edamalayar dam were opened Thursday. Next along the route is the Bhoothathankettu dam in Ernakulam district. The Periyar then winds its way through Kalady and Aluva on the last leg of its journey to drain into the Arabian Sea 24 km north of Kochi. Another branch of the river flows from Aluva to Kochi’s Udyogamandal before merging with the backwaters.
Threat to Kochi airport
In its journey to the sea, the Periyar comes within 2 km of Kochi’s international airport, the runway of which was built after reclaiming a paddy field. A stream called Chengalthodu drains water from the airport into the Periyar. When the Edamalayar dam was opened in 2013, water had flooded the runway; fears that the rising Periyar would also lift the Chengalthodu led to operations at the airport being suspended temporarily Thursday afternoon.
A first this monsoon
On both earlier occasions, the Idukki dam was opened in October, during the northeast monsoon. This is the first southwest monsoon that has seen the dam being opened, and when the Edamalayar dam too, has been opened.
-Indian Express
Idukki Dam releases water when Kerala is in Floods: Could this have been avoided?
10-8-2018
Kerala is facing serious floods. Army, Navy, NDRF, neighbouring states are all out. Dozens of people have died, landslides happening, houses washed away, the whole machinery is out to deal with the crisis.
In this flood crisis, Idukki & Idamalayar two of the Kerala’s biggest dams along with about two dozen others, are releasing water, adding to the floods and the disaster. Why are Idukki and Idamalayar, both having live storage capacity above a Billion Cubic Meters, releasing water NOW, when whole of Kerala is facing floods due to recent excessive rains? Standard excuse: The dams are full and they have no option but to release the water, they cannot store more. But why did they wait to start releasing water till the dams are full and they are faced with TINA: There is No Alternative. This love to be in TINA situation seems like a disease affecting all dam operators.
There are still two months of South West Monsoon for Kerala. Then large parts of Kerala also get benefits from North East monsoon that follows in Oct-Dec. In fact, the only two occasions (1981 and 1992) since the Idukki Dam was commissioned in 1975, were both during North East monsoon, never in SW monsoon. So they could have easily taken advance action to release water from Idukki when Kerala was not facing floods. They obviously did not and now, when Kerala is facing floods, Idukki is adding to Kerala’s misery.
In fact, just about ten days back, on July 31, 2018[i], the media was full of stories of possible release of water with water level in Idukki crossing 2395 ft, with FRL at 2403 ft. If they had started water in the intervening relatively dry period, Idukki dam need not have added to Kerala’s flood disaster misery. They did not. WHY? Why they again waited to be in TINA state when Kerala is also facing floods?
In fact, basic objective of Idukki Dam is power generation. Idukki dam has six turbines with 130 MW capacity each. One expected that this year Idukki power generation would have broken all records, since never before has the dam water level and inflows into the dam been so high. But when one looks at daily and monthly power generation figures from National Power Portal of Central Electricity Authority (CEA) and CEA’s own past records, one is shocked to see that during June-July 2018, Idukki generated about 325 Million Units (MU) of power, which was below power generated during at least four years in just last decade: below that in 2008, 2012, 2014 and 2015. In 2014, the highest generation year for June-July, Idukki generated over 50% more than it generated in June July 2018. If Idukki had generated more power, that could have also help reduce water level.
So why did Idukki power not generate more power when so much water was available. National Power Portal[ii] provides the answer: one of the six 130 MW units of Idukki has been under shut down since Aug 1, 2017 for Renovation/ modernisation and another 130 MW unit is under shut down since June 26, 2018 for annual maintenance. Its of course a mystery why the second unit was taken out for annual maintenance during monsoon, when it could have been done in dry season. But the consequences of this actions are that Idukki produced less power and it also added to flood disaster misery of Kerala.
In fact, even before the SW monsoon set in this year, on May 31, 2018, Idukki’s live storage capacity was 25% full, much higher than normal and higher than previous year or average of last ten years. That also contributed to the dam filling up sooner. Why such high water storage before the onset of monsoon is a question that the Idukki managers will need to answer.
Kerala Rainfall As per IMD (India Meteorology Department) figures, till Aug 9, Kerala received 20% above normal rainfall. Idukki districts tops with 50% above normal rainfall and also highest rainfall among all districts of Kerala so far: 2433.5 mm. Palakkad (44%), Kottyam (36%) and Ernakulam (33%) are some other districts having high surplus rainfall. But it’s possibly the bouts of high intensity rainfall that has created the current situation.
In Conclusion Its clear that major storage dams of Kerala like Idukki and Idamalayar, by releasing water when Kerala is facing floods due to widespread heavy rainfall, are adding to the flood misery of Kerala. This could have been avoided if the dam operators had started releasing water in advance rather than waiting for dams to be filled up, when they have no alternative but to release water. Its also clear that there was sufficient time and relatively dry period when they could have released water, rather than when Kerala is facing floods. If the Idukki power unit that was taken out or operation from June 26, giving “Annual Maintenance” as reason was in stead taken for annual maintenance during drier summer months, that would have helped, particularly when one unit is already out for renovation. If the water level in Idukki was lower before the onset of monsoon, it would have helped. CWC’s absence in flood forecasting is also additional handicap.
All this requires action. Possibly one of the first things, post current phase of rescue and emergency, that Kerala govt can do is to institute an independent inquiry into these issues, so that such situations do not recur, when dams, in stead of helping moderate the floods, add to the flood misery.
Himanshu Thakkar, SANDRP (ht.sandrp@gmail.com)
SANDRP
Idukki dam shutter opened after 26 years in Kerala following heavy rain
9-8-2018
This is the first time that the incessant southwest monsoon, which has caused a series of floods and landslides in several districts of the state, has forced the dam sluice gates to be opened.
In a historic move, the Kerala State Electricity Board (KSEB) opened one of the five shutters of the Cheruthoni dam on the Idukki reservoir as the water level inched up to 2398.99 ft. The shutters of one of the largest arch dams in Asia are being opened after 26 years. The maximum storage level in the reservoir is 2403 ft.
The dam, commissioned in 1975, has been opened only twice, both during the northeast monsoon in the months of October-November. This is the first time that the incessant southwest monsoon, which has caused a series of floods and landslides in several districts of the state, has forced the dam sluice gates to be opened.
The Kerala State Disaster Management Authority (KSDMA) made it clear that the middle shutter of the dam has been opened as part of a trial run for the next four hours to gauge the water level in the reservoir. The middle shutter has been lifted 50 cms, releasing up to 50,000 litres of water per second. The other shutters will be lifted only if a need arises. The SDMA said people living in a radius of 100 m along the banks of the Periyar river and in the low-lying areas must exercise caution as the shutter is being opened.
The water being released from the Idukki reservoir will travel through the Cheruthoni river to meet the Periyar after a distance of one kilometre. The river then passes by Thadambiyad, Karimban, Bhoothathankettu and Perumbavoor to reach Aluva. The Periyar drains further into the Arabian Sea.
-Indian Express
Seasonal water level in Idukki dam the highest ever
17/7/2018
Level reaches 69.3% of the total reservoir capacity
The Idukki dam clocked a history high recording with a seasonal water level of 2,375.52 ft on Tuesday.
It was 69.3 % of the total reservoir capacity. There was a rise of over 4 ft in the water level from the previous day. The water level on the same day last year was 2,316.98 ft, which was 20.92 % of its total capacity.
The main tributary, the Periyar continued to be in spate despite a lull in rainfall on Tuesday. On July 17, 1985, the water level reached 2,374.1 ft, which was the highest seasonal water level till now. On the same day in 1976, the water level reached 2,300 ft. The catchment area on Tuesday recorded a rainfall of 73.2 mm.
The water level in the Mullaperiyar dam steadily rose to131.2 ft on Tuesday. For the past four days there was an increase of two feet per day.
The Mullaperiyar sub-committee under the supervisory committee appointed by the Supreme Court is scheduled to visit the dam on Wednesday in the wake of the increasing water level. There was heavy inflow of water in to the dam and if the situation continued, the water level will reach the maximum level of 142 ft in a few days.
- The Hindu
Alert is out, countdown begins to shutter opening
With the catchment areas of the dam receiving heavy rainfall over the past several days, the water level in the dam has been increasing considerably.
31/7/2018
IDUKKI: An orange alert is out, with the District Collector Jeevan Babu K issuing it at 9.10 pm on Monday. Should the rain remain incessant, people settled downstream of Cheruthoni Dam — particularly in the Thadiyampadu, Karimban and Injivarakkuth areas on the banks of the Cheruthoni River — have two or three days to move out of their homes and shelters.
While clarifying there was no need to panic, the district administration issued the alert after the water level crossed 2395 ft. With the catchment areas of the dam receiving heavy rainfall over the past several days, the water level in the dam has been increasing considerably.“The water level is inching towards the full reservoir mark,” said a Kerala State Electricity Board (KSEB) officer.
“It has now crossed 2,395 ft and is going up by 0.06 to 0.08 ft every two hours. The rise in the level by two more feet will lead to declaration of the Red Alert. The full reservoir level is 2,403 ft, but we will start opening the shutters when the water level goes above 2,397 ft. If the inflow into the reservoir continues at the current rate, we may have to open the shutters within two days.”
Water will be released only during the day: Idukki Collector
The district administration said that four relief camps have already been set up to accommodate people in case of evacuation. “Of the 200 families living downstream, preparations are under way to evacuate 40 of them to relief camps,” Jeevan Babu said. “A control room has been functioning from Sunday night and red alert message signifying the extreme gravity of the situation will be issued 24 hours before the opening of the shutters.”
The Collector has also assured people living downstream that water will be released only during the day time, with all necessary precautionary measures having been taken to ensure security.
People have been restrained from visiting the area to see the opening of the Cheruthoni shutters. As estimated, the opening of the shutters at Cheruthoni — part of the Idukki dam project — will lead to water gushing to the Lower Periyar Dam and on to the Bhoothathankettu Dam. From there, water will flow through Periyar along Kalady and Aluva before merging with the Arabian Sea. Water is estimated to take nearly six hours to reach the Arabian Sea once the Cheruthoni shutters are opened.
If the shutters were to be opened, it will be the first time during the southwest monsoon since the construction of the dam in 1973. Twice in the past, the shutters had to be opened. But they were during the northeast monsoon (October to December).
The first instance was in 1981 (when the shutters were repeatedly opened and shut between October 29 and November 13) and the second time in 1992 (when they were kept open for 12 days from October 12 to 23). On both occasions, the water level in the dam touched the brim only when the storage built up during the southwest monsoon (June to September) was augmented by the inflow received following heavy downpour in the northeast monsoon.
The Idukki district administration has issued warning notices to the households and shops located downstream of the Cheruthoni Dam.
Many people who have cultivated crops on their agricultural land near the banks of the Cheruthoni river have started harvesting them, even though they have not reached maturity. Others have started to pack up their essentials to leave their houses, in case the red alert is issued.
2,395-ft mark was breached on Monday forcing the District Collector to issue orange alert. 135.80 ft is the new water level in the Mullaperiyar dam after it came down from Saturday’s 135.95 ft
Shutters of Neyyar dam opened
T’Puram: The shutters of the Neyyar dam were opened following heavy inflow of water into the reservoir from its catchment area. The four shutters of the dam were opened slightly by night. The full-reservoir level of the Neyyar dam is 84.75 metres. People living on the banks of the river downstream from the dam have been alerted.
‘Don’t fall for fake news on Idukki dam’
Kochi: A high-level meeting held in Kochi on Wednesday has urged public to not to believe fake news being spread in connection with the opening of shutters of Idukki and Idamalayar dams. MLAs, who attended the meeting held at Kakkanad, demanded cyber cell to take legal action against those who spread fake news through social media.
‘200 families will have to be evacuated’
Idukki: Terming the orange alert as just a standard operation procedure which is part of the dam safety protocol, District Collector K Jeevan Babu said there is no cause for panic. Allaying fears, he said people do not have to be evacuated soon after the alert. “When there occurs an emergency to evacuate people, it will be done only after alerting them and they will be shifted to the safest locations,” he said. According to him, only four relief camps need to be opened — in the Vazhathope, Mariyapuram, Kanjikkuzhy and Vathikkudy panchayats — near Cheruthoni. “The flood will affect 22 families in the Vazhathope panchayat alone. A total of 200 families will have to be evacuated, out of which 40 families will be evacuated in the initial phase,” he said. Those interested in moving to their relative’s houses will be allowed to go and the rest will be given refuge in the relief camps. Jeevan Babu said the district administration has not yet decided the date of the trial run and this will be done only after informing the people 12 hours before opening the shutters.
Water level comes down in Mullaperiyar dam
Idukki: Much to the relief of the people residing in the downstream of Mullaperiyar, the water level in the dam has come down to 135.80 ft on Monday compared to Saturday’s mark, which was 135.95 ft. The water level at the dam on Sunday was at 135.90 ft. The dam authorities attributed the decrease in the water level to the reduction in the rainfall in the catchment areas of the dam. The catchment areas of the dam, Periyar and Thekkady, received 13.2 and 1.2 mm rainfall, respectively on Monday. Similarly, the inflow of water into the dam has also shown a decreasing trend. The inflow into the dam which was recorded at 2,008.9 cubic feet on Sunday decreased to 1,807 cubic feet on Monday. Even as Tamil Nadu has reduced the intake of water from the dam to 2,100 cubic ft from 2,300 cubic ft, the dam safety officers told ‘Express’ that the water level in the dam was steady at 135.80 ft.
-New Indian express
Water storage crosses last year’s level in Idukki
13/9/2017
Still it is only 47.85% of the total reservoir level
For the first time since the southwest monsoon started, water level in the Idukki dam has crossed the last year’s storage level. The water level on Wednesday was 2,352.36 ft compared to last year’s level of 2,351.24 ft. this time.
This is 47.85% of the total reservoir level, which stood at 46.9 percentage on the same day last year.
According to an official at the Dam Monitoring and Search Station, Vazhathoppe, though there was no rainfall recorded on the catchment area for the past two days, there was good inflow through the main tributary, the Periyar.
The water level was lower than the previous year with poor rainfall during the initial period of the monsoon. The power generation at the Moolamattom Power House also remained at a low. The power generation on Wednesday was 5.32 m.u., which was 4.45 m.u. the previous day. (On Monday and Sunday it was 2.50 and 2.41 m.u respectively).
Though the water level still remained below the average level of the season, the minimum water level prior to the beginning of this monsoon was at a low of 2,299 ft. recorded on June 23, 2017. The official said that though the minimum water level normally would be above 2,300 ft, it fell further prior to this monsoon causing concern on a poor storage in the dam.
The generators and other equipment in the power house are undergoing a revamp reducing the generation level.
- The Hindu
Idukki dam water level reaches dismal depths
30/7/2017
Reservoir had only 22.68% of its total capacity on Saturday
With poor rainfall in the catchment areas, the water level of the Idukki dam is at one of its lowest levels in recent years.
The water level on Saturday was 2,319.80 ft, which is only 22.68% of the total reservoir level.
An official of the Dam Monitoring and Research Station, Vazhathoppe, said on Saturday that the percentage of water in the dam on the same day last year was 43.24.
Inflow dips
The inflow of water into the dam which was copious with the advent of the southwest monsoon has dipped, resulting in low power generation at the Moolamattom power house.
On Saturday, the catchment area recorded a rainfall of 29 mm and the power production was just 2.7 million units.
The official said that power generation was one of the lowest of this year.
The minimum water level of the season prior to the southwest monsoon was also low this year, the official said. Poor northeast monsoon contributed to the present situation.
The maximum water level of last year was 2,352 ft, recorded in September 2016. The Idukki dam is the largest contributor to power generated in the State.
Electricity Minister M.M. Mani told The Hindu on Saturday that the government had not considered imposing power cut so far.
However, load-shedding would be considered if the situation warranted, he said.
It would be done only after informing the public, the Minister said.
He denied that there was unannounced load-shedding in the State.
There was a problem regarding bringing of power from outside the State, Mr. Mani said, adding that electric lines needed to be strengthened.
The State generated only 30% of the power required here, that too when the hydroelectric projects operate in full swing. Upgrade of the transmission sector and reduction of transmission losses are prime concerns. If the situation persisted, the government might have to consider power cut. The situation on the power front was precarious, he said.
-the Hindu
No Idukki dam opening for three days
23/9/2013
With the increase in water level in the Idukki dam showing a declining trend, the Kerala State Electricity Board on Sunday ruled out the possibility of opening the Cheruthoni dam for three days.
K.K. Karuppankutty, KSEB (Dam Safety) Chief Engineer, told the media after visiting the Cheruthoni and Idukki dams that the inflow of water had declined following a fall in rainfall in the catchment areas, which was just 1.2 mm till 24 hours on Wednesday. The water level had been remaining almost constant at 2,401.68 ft since Sunday evening, said an official of the control room atop the Cheruthoni dam, which monitors the water level every hour.
Power generation at the Moolamattom power house was at the maximum level of 18.17 million unit.
The KSEB was against discharging water as it may cause flooding in downstream areas. Mr. Karuppankutty said there was no need for opening the dam as the water level was remaining constant.
“Only in case of a heavy rainfall and increased inflow, the opening of the dam needs to be considered,” he said adding that compared to the water level on Saturday evening, the rate of increase was only 0.18 ft.
However, the district administration is on alert with the water level at the dam almost at the brim in September itself.
The dam shutters had been opened in 1981 and 1992 (during October) when the water level was 2,402.17 ft and 2,401.44 ft respectively. Though a relieved atmosphere prevailed here on Sunday, District Collector Ajit Patil told The Hindu that the administration was on alert and the control rooms at the seven villages and at the two taluk offices downstream would continue to function. He said the officials had been ordered to keep vigil though the dam need not be opened for three days.
-the hindu
Countdown to Idukki dam opening begins
20/9/2013
Water level rising; the public and officials put on alert
All power generators below the penstock tunnels leading from Kerala’s largest hydel reservoir in Idukki are working round the clock in what appears to be a losing battle to prevent the opening of the dam shutters.
“The water level is inching towards the full reservoir mark,” K.K. Karuppankutty, Chief Engineer, Dam Safety, Kerala State Electricity Board (KSEB), told The Hindu here on Thursday.
“The water level has now reached 2,400.23 ft and it is going up by 0.02 ft every hour. The full reservoir level is 2,403 ft, but we will start opening the shutters when the water level goes above 2,402.5 ft. If the inflow into the reservoir continues at the present rate, in about 113 hours from now, we may have to open the shutters,” Mr. Karuppankutty said around 4 p.m.
The catchments of the reservoir have been receiving good rain since September 12, and the meteorological indications on Thursday were in favour of continued rain in the High Ranges of the State for at least three more days, which will mean heavy inflow into the reservoir for at least five or six days.
Meeting held
Electricity Minister Aryadan Mohammed called a meeting of top officials on Thursday to organise preparations for opening the dam shutters.
The meeting assessed that even if the storage of water was utilised at the maximum possible level by operating all the turbines generating power, the shutters of the dam might have to be opened anytime between September 22 and 24.
Top officials would proceed to the dam site from the KSEB headquarters on Saturday to monitor and oversee the preparations.
If the shutters were to be opened, it will be the first time during the southwest monsoon since the construction of the dam in 1973.
Twice in the past, the shutters had to be opened, but during the northeast monsoon (October to December) on both occasions.
The first time was in 1981 (when the shutters were repeatedly opened and shut between October 29 and November 13) and the second time was in 1992 (when they were kept open for 12 days from October 12 to 23). On both occasions, the water level in the dam touched the brim only when the storage built up during the southwest monsoon (June to September) was augmented by the inflow received immediately afterwards following heavy downpour early in the northeast monsoon.
Thus, the difference now is that the Idukki reservoir is reaching its full level with inflow received only during the southwest monsoon. As on Thursday, the State has received 31 per cent excess rainfall during the season.
Numerical weather predication models of the Chennai regional meteorological centre on Thursday favoured the possibility of widespread and heavy rain in Kerala during the next three days. An offshore trough was in position at mean sea level from the Karnataka coast to the Kerala coast and the southwest monsoon flow had quickened over the State, drawn by a low-pressure system over northwest Bay of Bengal.
Warning issued
Kattappana Correspondent adds:
The Idukki district administration has issued a warning that the dam will be opened on Saturday or Sunday.
District Collector Ajit Patil said the tahsildars and the village officers had been instructed to shift people living in the downstream areas in case of an emergency.
He said a public warning would be issued prior to the opening of the dam shutters and separate 24-hour control rooms had been opened at the taluk and the village levels. Mr. Patil said all precautionary measures had been taken, and the KSEB control room (ph: 9496 011974) was alerting various departments to the water level every hour.
An official of the control room said that though the rain had decreased slightly on Thursday, inflow was at a high level.
The phone numbers of various control rooms are: (04868) 275 293 (Thankamany); (04862) 230 888 (Upputhodu); (04868) 262 902 (Konnathady); (04868) 237 865 (Udumbanchola taluk); (04868) 260 302 (Vathikudy); (04862) 232 393 (Idukki); (04862) 239 582 (Kanjikuzhy); (04864) 276 201 (Vellathooval); (04864) 222002 (Mannakandam); and (04862) 222 098 (Thodupuzha taluk).
-the Hindu
Rise in water level in Idukki dam
19-9-2013
The water level in the Idukki reservoir rose steadily on Wednesday, by 1 ft over the previous day to reach 2,399.30 ft. The full reservoir level (FRL) is 2,403 ft.
On Tuesday, the increase in level was .5 ft and if the inflow continued at the same level through the main tributary, Periyar, the dam would be opened within a week. The increased level of water drawn by Tamil Nadu from the Mullaperiyar dam was a key factor in keeping the level in Idukki dam almost static till it rained heavily in the catchment areas in the past four days. Power generation at the Moolamattom power house was also raised to the maximum level to keep the water level under control. However, with the increased production level, there was high inflow of water causing a sudden spurt in the reservoir level.
The district administration has made preparations to open the dam shutters in case the water level rises above the FRL. Directions have been given to the village officers to take up evacuation on the downstream of the dam if the water level rose, District Collector Ajit Patil told The Hindu on Wednesday. He said there was no chance of a sudden water discharge as the water level in the Mullaperiyar dam was at a low. The water level there was 123 ft on Wednesday, also registering nearly .5 ft increase over the previous day’s water level.
Mr Patil said all precautionary measures had been taken. There was no need to panic as the increase in the water level was under control, he said adding that the people would be informed in advance if any decision was taken with regard to opening of the dam.
The average rainfall recorded in the district on Wednesday was 64.34 mm with the Peerumade taluk registering the highest rainfall of 123 mm. Udumpanchola recorded the lowest rainfall of 25.8 mm. Devikulam taluk, 70.2 mm. and Thodupuzha 32.7 mm.
-The Hindu
12/10/1992 The Assistant engineer in-charge of opening the dam recalls the tense situation. Water Level was 2400.7 feet. Slow opening in morning 9 am more opening in night.
“Tension built up like water in the dam,” says K R Gopalakrishnan. “My worry was whether the bridge ...
Read more at: https://english.manoramaonline.com/news/kerala/2018/08/01/raising-idukki-dam-shutters-tense-operation.html
Read more at: https://english.manoramaonline.com/news/kerala/2018/08/01/raising-idukki-dam-shutters-tense-operation.html
“Tension built up like water in the dam,” says K R Gopalakrishnan. “My worry was whether the bridge ...
Read more at: https://english.manoramaonline.com/news/kerala/2018/08/01/raising-idukki-dam-shutters-tense-operation.html
Read more at: https://english.manoramaonline.com/news/kerala/2018/08/01/raising-idukki-dam-shutters-tense-operation.html
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