Govt to start Yamuna floodplain demarcation from September 1
New Delhi: In a significant step towards protecting the Yamuna riverfront from unchecked encroachment and flood risks, the Delhi government is set to begin on-ground demarcation of floodplains, likely from September 1.
The move comes after the virtual mapping of vulnerable flood-prone areas was completed earlier this year, identifying stretches of land with a 4 per cent and 1 per cent annual probability of flooding, commonly known as one-in-25-year and one-in-100-year floodplains.
Officials said the Delhi Development Authority (DDA) has floated a tender to install bollards and signage along these zones, which will not only mark boundaries but also help track illegal occupations. Once the exercise begins, authorities
will be able to clearly distinguish floodplain zones and initiate removal of encroachments more effectively.
The process has been under the watch of the National Green Tribunal (NGT), which last year took suo motu cognizance of a report on the Yamuna’s floodplain vulnerability. The tribunal had constituted a committee led by the Delhi chief secretary to carry out identification, notification, and protection of the river’s sensitive zones under the provisions of the River Ganga (Rejuvenation, Protection and Management) Authorities Order, 2016.
The environment department, in its latest submission to the NGT dated August 12, informed that scientific assessments worth Rs 80 lakh had been undertaken by the irrigation and flood control (I-&FC) department to determine the extent of Delhi’s flood-prone land. The study referenced the 2023 floods, when the Yamuna rose to an unprecedented level of 208.66 metres, the highest recorded so far.
To ensure accuracy, the Central Water and Power Research Station (CWPRS), Pune, has been engaged to plug data gaps. Their final assessment is expected by August 31, 2025, after which physical demarcation will begin without delay.
Officials clarified that where inconsistencies exist in mapping, the outer boundary of the 1:100-year floodplain will be treated as the definitive reference. “The decision was taken after internal discussions, and agencies including GSDL and IFCD have been instructed to finalize the coordinates with clarity,” an official said.
Meanwhile, the DDA has confirmed that its survey of Zone O, the stretch covering major Yamuna floodplains in Delhi, is still in progress. According to the affidavit, nearly 814 hectares of encroached land in this zone has already been reclaimed. Once the signage and bollards are in place, authorities expect encroachment tracking and floodplain protection to become far more systematic.
