2 years after the order, Yamuna demarcation process yet to begin

The submission said the process of virtual demarcation is likely to be completed by August 2026, after which the DDA will complete on-ground demarcation.

The Delhi government has informed the National Green Tribunal (NGT) that the process of mapping out and demarcating a one-in-100-year (1:100) floodplain along the Yamuna is delayed. The work is expected to be completed by end of next year.

NGT had said that the delineation of Yamuna was required to prevent illegal developments in the floodplains. (HT archive)

The submission, dated December 5, said the Central Water and Power Research Station (CWPRS) in Pune – the institute tasked with completing the process, found that the data provided by the Survey of India (SOI) was inadequate for the required analysis, with a 28.3km stretch from Burari Garden till Okhla Bird Sanctuary yet to be mapped.

The submission said the process of virtual demarcation is likely to be completed by August 2026, after which the Delhi DevelopmentAuthority (DDA) will complete on-ground demarcation.

“The Irrigation and Flood Department (I&FC) has informed that the CWPRS has encountered technical limitations in preparing the map with 1-metre contour lines..” it added, adding that the institute will require five months to prepare the final map.

It added that the DDA has floated a tender for the said demarcation, but it can only be completed once the I&FC department and the Geospatial Delhi Limited (GSDL) finalise the map.

NGT had in October 2023 – soon after July 2023 Delhi floods, taken suo motu cognisance of a media report, forming a joint committee headed by Delhi chief secretary to identify and demarcate Yamuna floodplains as per the River Ganga (Rejuvenation, Protection and Management) Authorities Order, 2016.

It had said that the delineation of Yamuna was required to prevent illegal developments in the floodplains.

In August, the government told the tribunal it had completed the virtual demarcation of the 1:100 floodplain area starting September 1. However, the submission, dated August 12 – had no mention of the 1-meter contour spacing, prompting the tribunal to seek clarity on it.

The latest submission said that the GSDL has prepared a PDF map using the 1-meter contour data generated under the Delhi State Spatial Data Infrastructure (DSSDI) project (year 2007-2008).

In this map, the 1-meter contours have been superimposed on the 1:100-year floodplain boundary. ”It was observed that contours between 195 -215 m are falling under the 1:100-year floodplain covering Palla to Jaitpur Village…..It may be noted that no ground truthing has been carried out by the GSDL for preparation of the PDF map,” the submission added, stating the I&FC department will require to carry an on-ground verification.