New Delhi, July 13 -- The water levels in the Yamuna stretch in Delhi rose sharply on Sunday, increasing by over 2 metres following heavy rainfall in the hills upstream. This marks the first instance of the river crossing the 204m mark after a prolonged dry spell during the summer months, officials said. According to officials, the river rose from 201.87m at 10pm on Saturday to 204.05m at 11am on Sunday at the Old Railway Bridge, the standard flood monitoring point in Delhi. The level remains below the warning mark of 204.50m and is expected to stabilise. The increase marks the first significant rise in water levels after an extremely dry summer, which had led to extensive water supply disruptions in the city and a shortfall of up to 100 MGD during the peak crisis period. Data from the Hathnikund Barrage showed outflow reached 1,086.76 cumecs (38,378.85 cusecs) on July 10 at 10pm and 1,009 cumecs (35,661.1 cusecs) on July 11 at 2am, significantly higher than the normal release of around 352 cusecs. Officials said the water released from Hathnikund takes 48-72 hours to reach Delhi. While the river has turned brownish due to increased upstream flow, pollution levels downstream of Okhla remain high, with untreated effluents continuing to enter the river. Large sheets of toxic foam were seen coating the river at Okhla-Kalindi Kunj on Sunday. Typically, froth bubbles are caused by soap-like surfactant molecules. When water falls from a height at the Okhla barrage, it churns polluted water, increasing frothing. Froth formation intensifies in winter when bubbles become more stable, making such heavy formation during the monsoon relatively rare. A senior official from the flood and irrigation department said the rise in water level was expected due to sustained releases from Hathnikund over the past two to three days. "The water takes 48-72 hours to reach Delhi from Yamunanagar in Haryana. The level started rising last night, but the situation is well under control. The high flow will cleanse the river, marking the first episode of flushing the pollutants down. The water quality is likely to improve in coming days. There is no flooding risk at the moment," the official said. The official danger level of the Yamuna is 205.33m. In 2023, the river reached a record 208.66m after a discharge of 359,760 cusecs from Hathnikund, breaching embankments and flooding parts of Outer Ring Road and floodplains. Bhim Singh Rawat, coordinator of the South Asia Network on Dams, Rivers and People (SANDRP), said, "Yamuna bed has been completely dry this summer. This will help quench the river and start the period during which Yamuna resembles a normal river. Its overexploitation in non monsoon phase just reduces it to sewage canal during the other seasons."...