Flood alert: 'Yamuna floodplains drastically narrowed'

NEW DELHI: With land regulation along the Yamuna remaining lax, there is danger ahead. Not only is the river being constricted, but the floodplains itself has narrowed drastically between 1980 and 2014 - leading to fears that there can be massive flooding in Delhi in the coming years.

The signs are already there. In recent monsoon seasons, many areas in southeast Delhi have seen basements of buildings getting submerged under water.
A recent study by IIT Kanpur and Delhi University published maps that showed how the Yamuna's floodplains has narrowed drastically in three and half decades. The fear is that in the absence of an unambiguous policy to protect the floodplains, more river zone land will be diverted for construction, compounding the problem.

"The topographic and satellite maps of Delhi from 1980 to 2014 indicate temporal variation in channel geometry and the position of river Yamuna ... it is observable that after 1980 the remaining floodplain areas were rapidly occupied by settlements, civic structures, roads, bridges, flyovers, playgrounds and metro stations," said a study published in 2014 in the International Journal of Research in Engineering and Technology. It concludes that identifying and "delineating" features such as older and active floodplains, paleo-channels and meandering channels are essential for hydrogeological evaluation.

Afzal Khan, assistant professor at Shimla University and co-author of the study, said that the considerable impact of the encroachment on the Yamuna's channels has to be studied more thoroughly. The narrowing of the riverine plains has taken place despite the regulations provided for under Delhi Development Authority's "O" zone that disallow any permanent constructions and despite the Central Ground Water Authority having declared the Yamuna floodplains a "recharge zone".

Shashi Shekhar, head of the National Green Tribunal's Principal Committee on Yamuna and secretary of the ministry of water resources, said the panel was aware of the river's constriction, but explained there were no laws at the moment to protect against encroachments. "The land belongs to three agencies - DDA, Delhi irrigation department and UP irrigation department - which adds to the problem," said Shekhar.

The flow in the Yamuna ranges from 3,500 cusecs between December and February to as much as 8 lakh cusecs for a few days after the monsoon rains. According to experts, the much awaited notification of the River Regulation Zone drafted in 2002 could help regulate or prohibit activities on specified stretches of the river on both sides of the natural levee. The draft notification did go to the law ministry, but hasn't moved forward after it came back to the ministry of environment and forests.

The National Water Mission under the National Action Plan on Climate Change has also recommended zoning og floodplains to avoid climate change induced disasters. "We know that Germany and England and other countries have started to gradually remove dykes and embankments to be better prepared for floods," said Shekhar.

Contradicting the common belief that the Yamuna floodplains is fallow land that is much required by land-starved Delhi, Shashank Shekhar, professor at the department of earth sciences in Delhi University, said, "That is not so - the floodplains is the most important water reservoir for the city in times of crisis." He is worried about the encroachments that are visible in the bund road along Jaitpur and Sarai Kale Khan. He believed that the sudden flooding of basements in areas such as Okhla, Sukhdev Vihar and Lakshmi Nagar in recent years have been caused by "lack in connectivity of the floodplains to its catchment or its basin due of encroachments".