The Delhi Jal Board (DJB) told the National Green Tribunal (NGT) that sewer network work in parts of Sangam Vihar has been delayed by restrictions on construction in forest land and by pending road cutting permissions. The update was filed as a status report in a case on untreated sewage and sets out progress under the Delhi Sewage Master Plan-2031. The utility said phased work reflects complex ground conditions.

The affidavit said Phase II covers several colonies and has advanced in a staggered manner because of peculiar site conditions and other impediments. Sewer lines have been completed in eight colonies unaffected by forest encroachments, while work in 14 other colonies has been limited to portions outside forest land; 11 of those sites are partly on forest land. Affected pockets include Sangam Vihar's L, C, D and F-3 blocks.

The DJB reported that work in the partly forest sites is about 25 per cent complete and has been slowed by delays in statutory permissions, with projected completion by March 2027. Of the remaining three Phase II colonies, sewer laying has been finished in one, while work in two colonies in Durga Vihar, Deoli Extension, remains stalled because of public hindrance and local resistance. The utility said the executing agency could not complete the balance work.

Peripheral trunk sewer lines have been completed along major roads leading out of Sangam Vihar to intercept domestic sewage in storm water drains and convey it to the sewer network along Mehrauli-Badarpur Road and eventually to the 170 million (mn) gallons per day Okhla sewage treatment plant. For Phase I, sewer lines have already been laid in several unauthorised colonies including Shiv Park, Jawahar Park and Krishna Park Extension. The affidavit noted delays in a separate balance work package after the original contract awarded in May 2018 was terminated in September 2022. A fresh work order worth Rs 313.1 mn was issued in November 2025 to complete the balance package.