LET THE RIVER FLOW

Yamuna needs comprehensive cleansing of sewage and stronger water flow

- BY IEEVESH GUPTA

DELHI IS AN URBAN space totally gone wrong, with a population of around 20 million, way beyond its capacity. If we go downstream of the Wazirabad barrage, a series of 21 drains flows into the Yamuna, making it a giant drain. The city generates more than 3 million cubic metres of treated and untreated sewage.

The total mean annual flow for the Yamuna up to the Delhi stretch is 12-13 thousand million cubic metre (TMCM). The water abstraction from the river for irrigation and drinking till Delhi is about 10-11 TMCM. This leaves only a free river flow of about 2-3 TMCM. For the Yamuna, as for most Indian rivers, around 80 per cent of the flow occurs in the monsoon months (July to September) and the rest in the nine non-monsoon months. There is almost zero environmental flow available downstream of Wazirabad barrage during the non-monsoon months.

Haryana releases 10 cumecs (cubic meters per sec) of flow at Hathanikund during the lean season. However, most of it evaporates or percolates before it reaches Wazirabad.