![\"Cholabari](\"https:\/\/dialogue.earth\/content\/uploads\/2017\/10\/PIX-1-CHAURABARI-LAKE.jpg\")
Chorabari lake before the floods<\/h2>\n
Until it burst its banks, Chorabari was one of 14 lakes spread over the Mandakini river basin, all above 3,700 metres. At a height of 3,960 metres, Chorabari lake was almost two kilometres upstream of Kedarnath.<\/p>\n
The lake had originally formed from meltwater at the snout of the Chorabari glacier, but due to climate change, the glacier had retreated more than 200 metres, leaving a moraine of broken debris through which little water could flow from the glacier to the lake. Since the start of the century, if not before, the lake\u2019s water has come from snow melt and rain.<\/p>\n
As a result, the 250 metres long and 150 metres wide lake \u2013 with a depth of 15-20 metres \u2013 had very different volumes of water at different times of the year.<\/p>\n
Dehradun-based Wadia Institute of Himalayan Geology (WIHG) has a monitoring camp at Chorabari glacier. The scientists at the camp had found that the accumulating water was adding 2-4 metres to the depth of the lake every year. The greatest increase was of five metres in 2010, when they took measurements in October that year.<\/p>\n
Unusual at that altitude, such heavy rainfall attributes to climate change by scientists at the Intergovernmental Panel on Climate Change.<\/p>\n The result was a disaster not just in Kedarnath, but all the way downstream at Rambara, Gaurikund, Sonprayag and Agastyamuni.<\/p>\n D.P. Dobhal, a glaciologist at WIHG, has been studying the Chorabari glacier and lake for several decades. \u00a0explained why Chorabari lake burst its banks. \u201cA huge avalanche came down in the lake on the morning of June 17 and created immense pressure on the embankments. The lake had already much more water than usual and continuous rain had weakened its embankments. The sudden increase of pressure broke the moraine embankment and the lake emptied in a few minutes, taking a large amount of debris and huge boulders along with water.\u201d<\/p>\n In a detailed report prepared after the disaster, WIHG said, \u201cThe bursting of this lake led to its complete drainage in 5 to 10 minutes.\u201d Given the size of the lake, that meant over 262 million litres of water roared down the Mandakini within those ten minutes.<\/p>\n![\"Debris](\"https:\/\/dialogue.earth\/content\/uploads\/2017\/10\/PIX-4-CHAURABARI-GLACIER.jpg\")
What happened to Chorabari lake?<\/h2>\n
Useless Kedarnath wall<\/h2>\n
![\"Wall](\"https:\/\/dialogue.earth\/content\/uploads\/2017\/10\/PIX5-PROTECTION-WALL.jpg\")