Not reasonable timeline: NGT slams Delhi govt for delaying crucial 22-km Yamuna floodplain demarcation until 2026

The NGT directed the Delhi government to re-examine its action plan and submit a fresh report within two weeks proposing a shorter, realistic timeline for completing the exercise.

Timeline ‘unreasonable’

• We find that for other stretches in other states, the exercise of completing the ground truthing, putting of pillar and demarcation of floodplain of the river at the ground level has been completed expeditiously without any delay after receipt of the details from the Survey of India.
• Therefore, we find that the timeline of August 2026 given in the above reply is not a reasonable timeline.
• As far as the Central Water and Power Research Station (CWPRS), Pune, is concerned, it has been awarded the study for a scientific assessment of the impact on the floodplain area for Delhi region after the recent floods.
• In these original applications (petitions), as per the direction of the NGT, the exercise of demarcation of the floodplain zone of Yamuna river on a 22-km stretch in Delhi is required to be completed on the basis of the details supplied by the Survey of India concerning 1:100 years flood level with 1 metre contour.
• Hence, the work which is assigned to CWPRS may not have so much relevance for the demarcation of the floodplain on the basis of the details furnished by the Survey of India.

Physical demarcation yet to begin

• The Delhi Development Authority (DDA) informed the NGT that a tender had been floated for the physical demarcation of the floodplain, and the exercise would begin once the 1:100-year floodplain map with 1-metre contour lines is finalised.
• The NGT also took note of an intervention application filed in the matter and listed the case for further hearing on March 25, 2026.

Case based on media reports

• The NGT was hearing a plea based on an English daily on August 22, 2023, along with a petition filed in 2024 based on another news report dated April 17, 2024.
• Both matters concern the long-pending demarcation of the Yamuna floodplain zone within the Delhi stretch of the river, particularly the 22-kilometre segment between Wazirabad and Palla.

Scientific floodplain mapping

• In earlier orders, the NGT had directed authorities to demarcate the floodplain using the 1:100-year highest flood level along with a 1-metre contour mapping, a method already adopted for other stretches of major rivers such as the Ganga.
• The Delhi government, in a status report dated December 5, 2025, informed the NGT that the Survey of India had supplied data required for 1-metre contour mapping, which was shared with Geospatial Delhi Limited (GSDL) for analysis.
• A preliminary digital map had been prepared by superimposing 1-metre contour data over the 1:100-year floodplain boundary, indicating that areas with contour levels between 195 metres and 215 metres fall within the flood-prone zone between Palla and Jaitpur village.
• However, officials acknowledged that ground verification of the map had not yet been conducted.

Technical hurdles cited by authorities

• The irrigation and flood control department (IFCD) informed the NGT that a study titled “Scientific Assessment of Impact on Flood Prone Area for Delhi Region after the Recent Flood” had been assigned to CWPRS, Pune.
• The study was initially scheduled for completion by August 31, 2025, but the agency sought an extension until December 31, 2025, citing technical limitations in preparing the floodplain map with the required contour data.
• Authorities further informed the Tribunal that a 28.3-kilometre data gap between Burari Garden and the Okhla Bird Sanctuary had been identified, requiring additional data procurement from Airbus, after which CWPRS would need five more months to prepare the final map.
• Based on this, officials suggested August 2026 as the timeline for completion of the exercise.

Importance of floodplain demarcation

• Floodplain demarcation is considered crucial for protecting river ecosystems and preventing unregulated construction in flood-prone areas, especially in Delhi, where the Yamuna has witnessed repeated flooding in recent years.
• The NGT’s latest direction aims to accelerate long-pending efforts to scientifically identify and protect the river’s floodplain, a key component of urban flood management and environmental protection in the national capital.