The tendency of filling up reservoirs in the beginning and middle of monsoon season have been leading to avoidable flood disasters in the country. Apart from Kerala flood 2018, which was aggravated by mismanagement of reservoirs, various reports show that reservoirs in river basin of Cauvery, Krishna, Godavari and Ganga were also filled up well before the end of South West monsoon season. Resultantly there were many man made flood spells in downstream areas affecting lives and livelihoods of people.
Even as the rainfall during South West Monsoon of India during June Sept 2018 was 9.4% below normal, a number of HFL (Highest Flood Level) crossing flood events were recorded on CWC’s (Central Water Commission) Flood Forecasting (FF) website[i]. Since CWC’s FF site does not provide archived information or comprehensive list of such events, we are here putting together a list of such events that we had noted during the SW monsoon, for future records and also understanding trends of high floods. Continue reading “HFL crossing flood events during India SW Monsoon 2018”→
Bansagar Dam in Sone river basin in Madhya Pradesh already full, violating the rule curve, is ready to create yet another flood disaster along Sone river in Madhya Pradesh and along Sone and Ganga in Bihar.
As per Madhya Pradesh Water Resources Department website’s Flood Report[i] on Sept 10, 2018 afternoon (5pm) (see the screenshots of the website below), ten gates of Bansagar dam were opened by 0.5 m at 11 am on Sept 9, 2018, releasing 35315 cusecs water. The gates were further opened to 0.75 m at 4.40 pm on same date to release 54315 cusecs. A bit curiously, the website is completely silent about any gate opening before that, it implies that no gates were opened this year before 11 am on Sept 9, 2018. The website says the water level at Bansagar Dam reached 341.63 m at 12 noon on Sept 9, 2018, level is given only at intervals of 4 hours during the day. The Dam FRL (Full Reservoir Level) is 341.64 m, so it is likely that when they opened the gates at 11 am on Sept 9, the dam may have already reached FRL. The water level at the dam has remained at 341.58 m till 8 am on Sept 10, 2018, just 4 cm below the FRL, as per the latest available information. Continue reading “TALE OF A DISASTER FORETOLD: Bansagar Dam ready to create another flood disaster along Sone and Ganga”→
Central Water Commission is the only agency doing flood forecasting in India. As per CWC’s Flood Forecasting website[i] the Data Flow Map has information about 226 Flood Forecast Sites in the country comprising of 166 Level Forecast Sites and 60 Inflow Forecast Sites. It also monitors 700 Flood sites, information made available through List Based Exploration and Hydrograph View, but no flood forecasting is done for these sites.
In order to better understand the CWC’s flood monitoring and forecasting work, in this article, we have given an overview of CWC’s flood forecasting and monitoring sites in South India. It includes state wise list of CWC’s Level Forecast, Inflow Forecast and level monitoring sites in South India. Similar report has been published for North India[ii] and North East India[iii] andEast India[iv].
Tamil Nadu There are 3 Level Forecasting, 48 Level Monitoring and 14 Inflow Forecasting sites in Tamil Nadu State. Out of total 65 sites, 19 Level Monitoring and 2 Inflow Forecasting sites are inactive. MWL information is given only for 1 Inflow Forecasting site out of 14. IRRUKKANKUDI, Sathanur and Gomukhi sites are repeated with incomplete information. Out of 48, HFL figure and date is not provided for 25 Level Monitoring sites.
Traditionally, our river management strategies are mainly focused on the water flows, including flood management, and these have resulted in various interventions such as dams, barrages, canals and embankments. Most of these interventions have had very little consideration for sediment transfer and even if they did, they were generally defunct within a few years of their operations either due to improper design or inadequate maintenance.
A long-term sediment management strategy has never been a part of any protocol of river management, not just in India, but in several other parts of the world. It is amply clear that sediment management must form an important component of management strategies for the Himalayan rivers. The Union Water Ministry has recently circulated a draft policy on sediment management.
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.
It’s a bit intriguing situation. IMD and Skymet experts are downgrading the monsoon rainfall from earlier forecast 100% to 92%. Both agencies are predicting even lower rainfall in remaining part of current South West Monsoon. Bihar has received 413.2 mm rainfall till Aug 2, 2018, 22% below normal. And yet, starting Aug 1, CWC’s flood forecasting sites along the Ganga were showing ominous portents. For the first time this monsoon, the sites started showing steep upwards trend. Continue reading “Will sluggish Farakka again create prolonged floods along Ganga in Bihar?”→
Flood forecasting is an important activity during monsoon, considering the huge and increasing flood prone area, flood frequency, extent and flood damages. Accurate and timely flood forecasting can hugely help reduce the damages due to floods. Central Water Commission (CWC) is the only agency responsible for flood forecasting in India. To understand the CWC’s flood forecasting better, we have compiled the list of the various flood, inflow forecasting sites and flood monitoring sites in India.
In this compilation, we have given state wise list of CWC’s flood forecasting, flood monitoring and inflow forecasting sites, along with available details like rivers, sub basin, river basin, Warning level, Danger Level, High Flood Level, Full Reservoir Level, Maximum Water Level. As we see below, there are many gaps in this basic information for the sites that are part of CWC’s list.
The release of around 1.31 lakh cusecs of water in Yamuna from Hathnikund barrage at 09:00 hours on July 26, 2018, was certainly first surge of flood this monsoon in the river. But no one expected, most are still in the dark that the release would multiply by over five times in just two days! It is almost a month after the Southwest monsoon arrived. By this time the river usually floods couples of times.
Looking at the lack of significant rainfall in the catchment area over past weeks, the flood is unexpected and has taken many by surprise. The Irrigation and Flood Control Department, Delhi Government has issued warning for flood plain farmers and human settlements close to river banks, but the warning does not seem to commensurate with the flood peak that is likely to hit the capital in next day or two.
Yamuna has already crossed warning (204 m) and danger level (204.83) at Old Delhi Railway Bridge (ORB), Delhi. The High Flood Level is 207.49 meters, reached on Sept 6,1978 after around 7 lakh cusecs (cubic feet per second) water was released in Yamuna on 3rd Sept 1978 at 04:00 hrs from Tajewala barrage, that was decommissioned and replaced by Hathnikund barrage in early 1990s. The flood monitoring of River Yamuna began in 1963.
Since then, the river has seen high floods in 1988, 1995, 2010 and 2013. The 2010 and 2013 floods also crossed 207 metres mark but fell short of 1978 level.
(The figure above is screen shot of CWC Flood forecasting site showing no warning signs even at 5 pm on 230718)
Almost all the big dams in Cauvery Basin are full on the earlier ever monsoon date this year. This includes Krishnaraj Sagar, Mettur, Kabini, Harangi, Hemavathi and Bhavanisagar. They are almost full and have started releasing large flows to the downstream areas. This is when we are past just about six weeks of South West Monsoon, the North East monsoon would come after that. It means that the basin is facing major risk of floods in next 2-5 months. And yet Central Water Commission, India’s flood forecasting agency, seems to be in deep slumber. It has not even bothered to update the flood readings on its designated sites from the 2017 figures. Continue reading “Cauvery is facing very serious flood risk, but CWC is in slumber”→