ABSTRACT: Many independent observers have argued that dams have played a role in increasing the proportions of Kerala flood disaster during July-Aug 2018. This article shows that Kerala dams violated many basic norms and if operated prudently, could have helped. It shows how post dam floods are different than pre dam floods. It lists the steps that would help in future disasters involving dams. The lessons are useful for all large dams of India.
In theory, every dam can help moderate floods in the downstream areas, as long as and as much as the dam has space to store water. In fact, every action that helps to store, hold, recharge (to groundwater aquifer), delay flow of rainwater from the catchment to the river would help moderate flow and hence flood in the river. Our catchments are fast losing that capacity, with continued destruction of natural forests, wetlands, local water bodies and also soil’s capacity to hold water. Continue reading “Role of dams in Kerala’s 2018 floods”→
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 other sites, information is made available through List Based Exploration and Hydrograph View, but no flood forecasting is done for these sites.
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 East India. It includes state wise list of CWC’s Level Forecast, Inflow Forecast and level monitoring sites in East India. Similar report has been published for North India[II] and North East India[III] 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.
In its latest report, the Comptroller and Auditor General (CAG) has questioned implementation of sixteen National Irrigation Projects. Before this, the CAG has held mismanagement in dams’ operation responsible for Chennai floods in 2015. Both these reports are available on its website now.
The CAG report on National Irrigation Projects, tabled in Parliament on July 20, has revealed that sixteen major multi-purpose water projects, taken up on an expeditious basis about a decade ago, are nowhere near completion, with no work being undertaken in as many as 11 projects despite the incumbent govt’s much-wanted focus on improving irrigation facilities in the country.
The report also mentioned that out of the 16 projects, undertaken under the Accelerated Irrigation Benefits Programme (AIBP) in Feb 2008, only five projects with estimated irrigation potential of 25.10 lakh hectares were under implementation and even these projects suffer from 8 to 99 per cent shortfall in physical progress, the CAG said. The remaining 11 projects with estimated irrigation potential of 10.48 lakh hectares are yet to commence and are at different stages of approval.
In a recent article Ashwin B Pandya, Former, Chairman Central Water Commission (CWC) refuses to acknowledge either the adverse impacts of dams or the better option of using groundwater aquifer for storing water. And thus making unscientific arguments against dam decommissioning and for dams. No one is talking of removal ALL dams as the author seems to postulate and then dismiss it as impossible and irresponsible.
Aquifers in 16 States in the country are contaminated by uranium, whose presence in drinking water has been linked to chronic kidney disease by several studies, a recent study has shown. More importantly, uranium doesn’t figure on the list of contaminants monitored under the Bureau of Indian Standards’ drinking water specifications. The main source of this contamination is natural, but groundwater depletion by extensive withdrawal of water for irrigation and nitrite pollution due to the excessive use of nitrogenous fertilisers may be exacerbating the problem, said the study.
– The study was carried out by a team of researchers led by Avner Vengosh, professor of geochemistry and water quality at the Nicholas School of the Environment at Duke University in the US. The team, which also included experts from the Central Ground Water Board, the Rajasthan government’s Ground Water Department and Gujarat Water Resources Development Corporation, analysed groundwater samples from 226 locations in Rajasthan and 98 in Gujarat.
The Central Water Commission (CWC) of India’s Union Ministry of Water Resources periodically updates India’s National Register of Large Dams (NRLD), the latest edition seems to have been put up recently[i]. Significantly, this latest edition reports huge jump in number of large dams in India, compared to the previous editions from 2009 that SANDRP has been monitoring. The 2009 edition of NRLD had 5100 large dams and the editions from 2012 to 2016 had listed 5190 to 5170 large dams, but the 2017 edition suddenly reports that now India has 5701 large dams, a jump of over 510 from the editions in last five years. This shows that neither states had been reporting correct figures of number of large dams in India, nor was CWC bothered to collect correct basic information about large dams. Continue reading “India’s National Register of Large Dams: Shows how little we know about our dams”→