The Yamuna river's capacity to hold water has alarmingly dropped by 50 per cent compared to four decades ago, putting New Delhi at a significantly higher risk of severe flooding. Today, a much smaller volume of water released from upstream can cause devastating floods, a danger that experts say has been ignored for years despite repeated warnings.
In September 1978, when a massive 800,000 cusecs of water were released from the Hathni Kund Barrage in Haryana, the Yamuna's level at Delhi's Old Railway Bridge reached 207.49 meters.
In July 2023, a release of less than half that amount—just 359,000 cusecs—caused the river to swell to a record-breaking 208.66 meters, submerging parts of the city. These figures clearly show that the river has become much shallower and narrower.
The Twin Culprits: Rampant Encroachment and Siltation
The two primary reasons for this dangerous situation are:
Encroachment: Widespread illegal construction in the Yamuna's floodplain (Khadar), the low-lying area that naturally holds excess water.
Siltation: Massive deposits of silt and sediment on the riverbed, which have drastically reduced its depth.
Despite numerous reports from both Delhi and Central government committees flagging this issue, construction and debris dumping in the floodplain continue unchecked.
A River In Chains: How Sandbars And Bridges Are Choking The Yamuna
The river's natural flow is being systematically choked. Due to the failure to de-silt the river, huge sandbars (islands of sand) have formed near key areas like the Signature Bridge and ITO Barrage, obstructing the water's path.
Furthermore, a 22-kilometer stretch of the Yamuna in Delhi is cluttered with 3 barrages and 20 bridges. Temporary paths built in the riverbed during their construction are often left behind, trapping more silt and further blocking the flow. This has also caused the water to reach Delhi much faster than before, reducing reaction time during a flood alert.
Official Warnings Ignored For Years
A February 2024 Parliamentary Standing Committee report highlighted that the situation is worsening due to illegal sand mining and debris dumping, citing 3,792 cases of illegal mining in Haryana in five years alone. The committee recommended creating a coordination portal for states and exploring controlled dredging (the process of excavating silt from the riverbed) to clear the blockages. However, no significant action has been taken on these suggestions.
The constant obstruction is a recipe for disaster. As BS Rawat, Coordinator for the South Asia Network on Dams, Rivers and People (SANDRP), warns, "If the river's natural flow continues to be obstructed in this manner, Delhi could face a severe flood crisis."