Re-greening the denuded hill slopes surrounding the Guwahati city is the only lasting solution to its perennial waterlogging problem which is compounded by the large deposits of silt coming down along with the rain water. The ever-increasing population pressure on the hills is resulting in the city fast losing its green cover with the consequence that even a short burst of shower is enough to inundate vast areas. Observing this, Chief Conservator of Forest Mohan Chandra Malakar today said it is high time the green cover on the hill slopes was restored by tree plantation or even with grass, enabling it to soak the rain water and prevent soil erosion.