In India, seven cities have earned the title, 'City of Lakes' for their extensive list of natural and artificial lakes. These are Udaipur, Bhopal, Shillong, Kodaikanal, Nainital, Thane, and Srinagar. However, the Delhi Jal Board (DJB) has been making preparations since 2018 to ensure the national capital is added to that list in the next three years.
During his visit to Timarpur village in North East Delhi on January 1, 2022, where the DJB is constructing a sewage treatment plant (STP), state water minister and DJB chairperson Satyendar Jain announced that a 20-acre lake will be built here with the treated water.
He also tweeted that in the next three years, 25 such lakes and 600 water bodies will be rejuvenated in Delhi. "This is a step towards making Delhi a city of lakes," Jain further said in the tweet.
The 'City of Lakes' project was launched on December 24, 2018, by Chief Minister Arvind Kejriwal who approved Rs 376 crore for the rejuvenation of 159 lakes in Delhi and Rs 77 crore towards the creation of two mega lakes at Rohini and Nilothi.
This project aims to increase water supply to meet the city's daily demand of 1,140 million gallons (MGD). The current water supply of the city is 940 MGD; short by 200 MGD. Ankit Srivastava, environment engineer and technical advisor to the state water minister, said, "The City of Lakes project has two focus areas - lakes and water bodies. Besides, we are trying to use the old and historic drains, canals and minors, from where we can recharge water."
"Also, we had sought permission from the Delhi Development Authority (DDA) to maintain its lakes without claiming our name on it. We also got NOC from DDA to take over its 550 water bodies, while tenders have been floated for 350 water bodies, and work on 50 of them is nearly over," he added.
Srivastava added, "The goal is to revive all water bodies in Delhi. As we had no model of holistic revival to follow, we created our own model - Rajokri project, as a pilot project in 2017. Here, we created an artificial lake with treated water, and even built an amphitheatre."
Use of innovative technology
Delhi receives rainfall for only 15 days in a year, so it was important to focus on treating wastewater, instead of solely relying on rainwater. Construction of STPs were planned in such a way that the water can be treated and reused at the same place without making it flow through different sewers and canals.
To rejuvenate the lakes, the areas are cleaned up, and with natural STPs, the waters from polluted water bodies are flown into a mechanism similar to an artificial lake.
A natural STP is a sedimentation tank combined with a constructed wetland that can remove pollutants. Earlier only 15 litres of rain water used to get recharged. After STPs were installed, water has become available on all 365 days, varying between 1 lakh and 6 lakh litres gets recharged.
Purpose of water bodies/lakes
The purpose of the revitalisation project was to create a reservoir to stop urban flooding and to avoid choked drainage. The government also wants to enhance the aesthetic value of the landscape by ecologically reviving it and restoring the flora and fauna of the area around it.
According to DJB officials, villages had stopped getting adequate water due to rapid urbanisation, which is why rejuvenating waterbodies is looked at as a solution to create a buffer zone to store, recycle, and reuse net water.
Revival of dry tube wells, groundwater recharge, improvement in health, cleaner air for the villagers, were some other reasons why the government decided to convert barren lands into water bodies and lakes.
What experts say
Officer on special duty, Council of Scientific and Industrial Research (CSIR), Dr Rakesh Kumar said, "Initially, it appeared to be a difficult task. It was after successful pilot projects like the one in Rajokri, we thought of planning ahead. I cannot comment on what will happen once all the lakes are completed or whether the city's water demand will be met or not. All, I can say that the rejuvenation process will raise ground water. Following which, locals will start depending on treated water from the water bodies, instead of supply from the government. This will bring in a lot of balance."
He added, "Protecting a water body by building boundary walls around it acts as a death knell. The lakes will dry and die, like the Roshanara and Shahdara lakes, currently being restored."
Costing of water bodies/lakes
DJB has set up separate budgets for water bodies and lakes. According to officials, DJB has approved Rs 1-1.5 crore per acre for each water body; inclusive of operational and maintenance costs. For lakes, it is Rs 1-1.5 crore. For example, for the 60-acre Rohini Lake, the government has allocated Rs 64 crore.
Rejuvenation of lakes involves three components - construction of treatment plant, lake and landscaping. These are expensive. Tube wells, water polishing units are being built in catchment areas, and in some lakes, STPs are being created inside the lake, which add to costs.