BENGALURU: Around 1,000 trees have been converted into recharge points to replenish and increase groundwater levels in Peenya by ISTRAC ISRO.
Prof V Jagannatha, deputy manager and a scientist/engineer at ISRO Telemetry Tracking & Command Network (ISTRAC), came across this method during his trek in the Western Ghats in 1994. A civil engineer who specialised in environmental engineering says the method opted is extremely easy and inexpensive.
In this method, circular trenchers are dug two-feet deep around the trees. Water after rains or from any other source then directly would flow into these concrete pits, and can go up to 50-feet deep, thus allowing 2,000 litres to a maximum of 5,000 litres of water, to percolate and stay within these pits. This in turn leads to rise in ground water levels in the surrounding regions.
Prof Jagannatha says that over the three years they have started implementing this method, they’ve observed a lot of subtle changes in the area. “Firstly, soil moisture content has increased. Secondly, trees don’t shed much leaves during summer. Also, the levels of water were very low in the borewells earlier. Now, we are able to hear the splash of water when we throw a stone,” he says.
Stopping the flow of running water and allowing it to percolate is the key philosophy of this method, which is neglected in the most urban watershed management methods. If adopted in a city like Bengaluru, it can produce great effects, given that there are between 12 and 17 lakh trees in this city, he adds.
Although methods like afforestation can be practised along side, they continue to fall under big budget schemes of the government, he says adding, “this method of conserving water is relatively economical and environmental friendly.”
In Peenya, this practice is implemented with the help of an existing workforce involved in external environmental maintenance of the ISRO ISTRAC campus.
Prof Jagannatha firmly believes that each resident can take up the task of converting trees to recharge points and increase the soil moisture content. Roadside trees and park and open spaces especially of the central government and corporate campuses could be the focus points, he suggests.
Manvel Alur, founder of ENSYDE, an NGO working on environmental solutions comments, ”Digging of such trenches around trees is a very useful method to increase the ground water level, especially given the flash-flood rain patterns in the city. It is of common knowledge that trees should not be cemented up to their barks and enough space has to be left around them for water percolation. Sadly, this does not happen in most cases.”