CM wants IIT-D report on waterlogging implemented

The Indian Institute of Technology (IIT) Delhi on Wednesday presented its report on the causes of waterlogging and flooding in Delhi to the Chief Minister Arvind Kejriwal. The CM has directed the concerned departments to take concrete steps for the implementation of the report, which mentions in detail the specific reasons for waterlogging and flooding during monsoon season.

The report on stormwater drainage infrastructure has been prepared by the Department of Civil Engineering, IIT Delhi, which has been commissioned by the Department of Irrigation and Flood Control. The report identifies the reasons behind clogging of specific sewers and drains.

The report notes that to alleviate the flooding conditions in various parts of the city, the storm-water infrastructure has to be made efficient. So, it is pertinent to apply corrective measures to the faulty drainage infrastructure, and introduce low cost flood preventing measures such as water-bodies rejuvenation, rainwater harvesting using parks and low impact Development options.

 Further it also says that the solid waste and the sewage have to be managed in such a way that they do not interfere with the storm water drainage.

According to the information given by CM office, the last drainage Master Plan for Delhi was prepared in the year 1976, when the population of Delhi was 60 lakh. However the population of Delhi as per Census 2011 stood at 1.67 crore  and the projected population as per projection in Master Plan Delhi 2021 is 2.5 crore.

The report states that Delhi has three major drainage basins, namely, Najafgarh, Barapullah and Trans-Yamuna basins.  

According to the report in the Trans Yamuna Basin the rapid unplanned urbanization, shallow groundwater level and low elevation have resulted in frequent flooding problems. "The majority of areas lying in the western side face frequent water logging problems, primarily due to shallow groundwater levels during pre and post monsoon periods," it stated.

While as per the report the Barapullah Basin region is protected by a check dam in the Mehrauli area to prevent surface runoff coming from Haryana state and also to prevent water logging in the area.

It also highlights the problem in the Najafgarh basin saying that drains carrying storm water from outside Delhi which have their origin in the other states and carry considerable discharges into Delhi. 

 "Pumps have been installed at various locations by the government to pump out the storm water into the Najafgarh drain. The failure of these pumps leads to drainage congestion in these areas. In addition, constant usage of mobile pumps to pump out the surplus amount of water into nearby drains, whenever required, affects the capacity of the drain and causes flooding in the downstream areas," it said.

The report says that the storm drains should be treated as key public assets and no encroachment should be allowed. "Any encroachment of the drain should be immediately removed and reported back. Department managing the storm drain should be made responsible for keeping drain encroachment free. Special drives to remove encroachments from the storm drains should be taken up," recommends the report by IIT-D.

Further the report states that no natural or artificial storm drain should be allowed to carry any sewage and only treated sewage of acceptable quality as per Central Public Works Department (CPWD) norms should be allowed in storm drains.

"All drains that are entering into NCT of Delhi(from Haryana, U.P., etc.) should be only carrying storm water and treated sewage of acceptable quality as per Central Pollution Control Board norms," it recommends.

Adding, that the ongoing practice of Delhi Jal Board (DJB) , of puncturing sewer lines and draining sewage into storm drain in the event of blockage should be stopped.

"DJB should resort to using latest mechanisms such as supper suckers for de-clogging the sewer lines," recommends IIT-D among other measures.