The River Ganga traverses a huge course of more than 2500 km through 5 states of North and East India—Uttarakhand, Uttar Pradesh, Bihar, Jharkhand and West Bengal. Tolly Nullah discharges it’s flow into River Hooghly (Ganga) at Kolkata.
Tolly’s Nullah (also known as Adi Ganga) is an important and major drainage channel with strong tidal influence. Rapid and unplanned urbanization, particularly in the southern and south-western parts of Kolkata, channel bank encroachment, disposal of raw sewage and poor management of solid waste generated from households, livestock and religious activities and above all, lack of maintenance contributed to severe environmental pollution of the Nullah. Therefore, abatement of pollution of Tolly’s Nullah is important for the efforts being made to clean the River Ganga at its downstream.
The Government of West Bengal (GoWB) has decided to rejuvenate Tolly’s Nullah into a SW-II class water body (suitable for Bathing, Contact Water Sports and Commercial Fishing) and improve the aesthetics of the surroundings as a scheme of the NGRBA to be implemented by the KMC.
To assess the existing arrangements for wastewater and solid waste management in the Tolly’s Nullah drainage basin (“The Basin”), identify the issues which contribute to the pollution and consequent environmental degradation of the Nullah and develop strategies to redress the situation in the short-term, the medium term and the long term. Egis shall prepare Master Plan for implementation of the above strategies and transform the plans into implementable Detailed Project Reports (DPRs) and Bid Preparation for pollution abatement and rehabilitation of the Nullah. Scope of work is described as below:
Mapping the Nullah, its Basin and Infrastructure: A preliminary survey of the Nullah and its basin and prepare a work plan for undertaking surveys to prepare accurate maps and drawings that delineates catchment area, its hydraulic characteristics, length and cross-section of the Nullah at various locations, historic trends of flow recorded in the nullah, location, number and characteristics of outfalls discharging into the Nullah, and survey of the existing sewerage and drainage system and prepare the maps and drawings .