‘NCR needs integrated drainage system’

A drainage proposal, approved by the National Capital Region Planning Board, has recommended that a master plan should be prepared for inter-state regional drainage and also for individual cities and towns of the NCR spread over an area of 53,817 sq. km.

After examining various aspects that have a direct impact on the drainage system, the board said the participating states and their concerned agencies had to add details to the proposal by formulating district-wise action plan for its implementation. The board said the same can be done after detailing out projects and identification of sources of funding through convergence with other government schemes. National Capital Territory of Delhi comprises 13 districts of Haryana sub-region, seven districts of Uttar Pradesh and two districts of Rajasthan.

The proposal said there was an urgent need to plan and design the drainage system of the city based on catchments and taking into consideration, topography, slopes, rainfall intensity and future expansion of the urban areas in an integrated manner. It pointed out that increasing road networks for urbanisation and increase in urban population has resulted in construction of a large number of flyovers and bridges. Due to shortage of land, the piers of roads and railway bridges are being constructed in major storm water drains and rivers in the cities. The plan said that these could cause backwater effect and flooding of upstream catchments. “There is a need to design all the roads and railway bridges in the cities crossing drains in such a way that they do not block flow resulting in backwater effect.”

The board said covering of drains has been posing difficulty in cleaning them and as a result it reduces their carrying capacity. During non-monsoon period, the drains have little or no water. “However, it has more moisture which it retains for longer duration due to more organic content in the soil of the drain. The grass and plants need to be regularly removed to maintain the flow of the drains.”

The plan said that Delhi has 11 major inter-state regional drains with Haryana, UP and Rajasthan. “While designing the drains, it was necessary to maintain the slope of the drains to allow continuous flow in them. Master Plan for Inter-State Drainage Basins should be prepared jointly by the concerned state governments and their agencies, River Basin Organisation and scientific institutions. However, construction could be taken up by the concerned state governments of the district maintaining the designed invert levels.”

The board said that the master plan for drainage should be prepared for towns and cities by the concerned state governments in collaboration with urban local bodies, urban development authorities, River Basin Organisation and scientific institutions in a time-bound manner. “Master plan for drainage to be prepared for all Class I towns of the NCR in the first phase. Sewerage Master Plan should be prepared to improve the coverage of the sewerage system so that sewage is not discharged into storm water drains.”