According to Additional District Magistrate (ADM) Ravindra Kumar, the drive to demolish the illegal structures was launched on Wednesday.
"Eighteen houses have so far been demolished. The remaining 70 houses, illegally built on the Yanmuna floodplains, will also be brought down soon," he said.
Kumar said the NGT had ordered to demolish all the illegal structures on the Yamuna floodplains.
He added that as per the order, 87 structures had to be brought down by October-end.