In a mountain village in southwest China’s Sichuan province, authorities have demolished seven small dam projects this year along a river to clear illegal developments in a new nature reserve. The demolition is part of a nationwide programme to close hundreds of tiny and often ramshackle dams and turbines and bring order to China’s massive hydropower sector after years of unconstrained construction.
The dams sat on an unnamed tributary of the fierce and flood-prone Dadu river, which feeds into the Yangtze, Asia’s largest and longest river, where the government says the “irregular development” of thousands of small hydropower projects has wrecked the ecology. But green groups say the campaign will not necessarily save the environment because it will not affect big state hydropower stations, which they say have caused the most damage.
On the 48 km Zhougong, authorities have already demolished small projects built in nature reserves or encroaching upon new “ecological red lines” drawn up to shield a quarter of China’s territory from development.
The government says small dams have disrupted the habitats and breeding patterns of many rare species of fish, although green groups argue the damage wrought by bigger dams is more severe, with entire towns and ecosystems submerged in water, which they say increases the risk of earthquakes, landslides and even climate change.
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.
Central Water Commission (CWC) measures and monitors water level at 700 hundred Flood Forecasting site in the country. It publishes this information on its Flood Forecast website[I]. The website has three ways to get this information: Data Flow Map, List Based Exploration, and Hydrograph view. The Hydrograph view provides information for past 72 hours, supposed to be updated every hour. This is in addition to the list of current forecasts.
As per the website 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.
In order to better understanding the CWC’s flood monitoring and forecasting work, in this article we have given state wise list of CWC’s Level Forecast, Inflow Forecast and level monitoring sites in North East India. For better understanding, we have also included part of West Bengal that is in Brahmaputra basin here, in addition to the 8 North Eastern states. Similar report has been published for North India[II] and we hope to publish reports covering other regions of India too.
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 second wave of floods (first wave came in around May 20-24) this year inA North East India is affecting Tripura, Mizoram and mainly Barak Valley in Assam. Worryingly, while CWC flood forecast site shows water level reaching unprecedented levels in Manu river at Kailashahar in North Tripura District, CWC seems to have NO flood forecasting site in Mizoram. At Matizuri site in Hailakandi district in Barak Valley in Assam, the Katakhal river also approaching its highest ever flood level. In Bangladesh too sites like Amalshid have crossed the HFL. Continue reading “Floods in Tripura, Mizoram, Barak Valley in June 2018”→