The Yamuna flood plain: A hidden treasure

Army personnel construct temporary bridges over the Yamuna for the three-day World Peace Festival organised by spiritual guru Sri Sri Ravi Shankar in New Delhi on Tuesday. — PTI

Is the best way to save a virgin forest to have three million people stomp around on it and take a pledge to save it Is the best way to save a flood plain to clear its vegetation, flatten it and dump stone and dirt on it and have three million people stomp on it Just good intentions and a little knowledge will not go to ground. The event to draw attention to save the river Yamuna, organised by the Art of Living foundation, may turn into the Art of damaging the invaluable living resource of the Yamuna flood plain. Such an event could have been easily arranged at an alternative site — the Jaypee Buddha International Circuit in Greater Noida.

Now, in response to a public interest petition by Manoj Mishra to the National Green Tribunal, a large fine has been imposed on the organisers. We would like to make the people and the organisers aware of the consequence of their well-intentioned extravaganza.

The water contingency in Delhi that followed the Jat agitation was a bolt from the blue. Suddenly, Delhi woke up to the fact that it lives entirely on imported water from the Ganga, Yamuna and Beas. All the water supply comes through canals or pipelines through Jat country in UP and Haryana. Any farmer protest can cut it off. Delhi is vulnerable.

The Delhi state government has rushed to look for contingency supplies. They rushed to the quickest and most visible fix. Make lake storage in northern Yamuna flood plain at Palla. They forgot that the Palla flood plain is an invisible natural storage that gets recharged naturally by monsoon rain and floods each year. They do not know that the flood plain in Delhi has enough contingency supply for over a month of water supply for 20 million Delhi. They forgot that a lake on the flood plain will dig up vast quantities of sand and ruin the floodplain. That it will have 2 meters of water evaporation loss.

The Delhi Palla Flood plain project In April 2009, the Prime Minister’s secretariat (PMO) initiated the Yamu-na Flood plain Project based on a study of one of the authors (Vikram Soni) on flood plain hydrology that indicated a major potential of the Yamuna flood plain to supply drinking water supply to the city of Delhi. This scheme uses local river flood plain subterranean sand aquifers, which have natural storage and are naturally recharged from monsoon rain each year to provide a regulated, perennial and sustainable supply of large-scale water to the inhabitants of Delhi. Natural Heritage First worked very hard with the lieutenant governor of Delhi (Tejinder Khanna) in the Technical Advisory Group of Yamuna River development authority to get a landmark decision for protection of flood plains for water recharge and biodiversity.

Sandy river aquifers of the Yamuna are 5-20 kilometres wide and can be between 50-100 meters deep and run for over a thousand kilometres. More than a third of this volume is water.

This flood plain aquifer is a huge underground lake! But ecological yields are limited by Delhi’s scanty annual rainfall of 60 cm. Nevertheless, on average, the approximately 50 km-long Yamuna river floodplain in the NCT can supply 250 million cubic meters of quality water each year — enough for over 3 million people (reported in the journal “Current Science).

However, since most of the southern flood plain is encroached, at present only the relatively free northern flood plain from Burari till Palla is being non invasively ‘’conserved and used’’ for the Yamuna flood plain project. This scheme will provide drinking water for one and a half million people in Delhi — 100 million cubic meters per year. The project is already under way and will be implemented by the Delhi Jal Board in a few months. At rates charged by water tankers(Rs 1,500 for 10.000 litres (10 cubic meters)), it has a water value of 1500 crores a year. River flood plains could provide a perennial and sustainable water supply for more than 300 cities in India at almost no cost.

The Art of Living festival We want to highlight the value of the floodplain in Delhi. For the porous, sandy flood plain, monsoon rainfall and floods can recharge about 30 cm ( 0.3 meters) of raw water every year. The 1000 acres that will be impacted by the Art of Living event has a potential of giving a perennial and sustainable supply of over 1 million cubic meters of water a year.

At the rate of tanker water it values to about `20 crores per year. A water stressed city like Delhi cannot afford to damage such a perennial survival resource.

Besides, it is the floodplain that feeds the river in the lean season and provides all the tubers and feed for the birdlife from its wetlands.

The flattening and dumping of mud will certainly undermine the porosity and storage and ecology of this large tract of flood plain. The Art of Living has other well meaning suggestions of downloading enzymes into the river to deal with sewage. This is not a symbiotically tested treatment — it is not even a clinically tested treatment. It could end up poisoning the birdlife by disturbing with their metabolism.

Most such treatments end up with unknown adverse side effects which tamper with nature. Though godmen with the best of intentions may want to do good by the river by this signal event, the ecological value of the flood plain (and nature ) simply does not permit such intervention.

The contingency water reserve The other idea of building the large water storage on the Palla flood plain as a contingency supply is, unfortunately, a foolhardy idea. A 2 km by 2 km lake of 8 meters depth would take up a huge agricultured or tree space, finish the flood plain, dump an enormous volume of sand — we do not know where! It would lose over 2 meters of water a year by evaporation and finally store only 20 MCM of water. Compare this with what nature has already provided in just the northern floodplain — 100 MCM of contingency water a year that is local perennial, sustainable and safely stored and recharged underground.

The flood plain is seen as a sandy stretch and not an invaluable water survival resource for the city — simply because it is “invisible”. It is clear that both the philanthophists and the state government must learn a little more about this. The loss of this amazing evolutionary resource would be irreversible.

Vikram Soni is emeritus professor at JNU and Jamia (physics and ecological wisdom), Anand Arya is a veteran ornithologist and concerned with the environment, Diwan Dingh is an environmental activist (Natural Heritage First), and Ranjit Nair is president, World Institute for Advanced Study