Yamuna pollution: First of 11 constructed wetlands in South Biodiversity Park starts treating sewage

The constructed wetland has been created using just boulders and plants, Prof C R Babu, who heads the Centre for Environmental Management of Degraded Ecosystems CEMDE at Delhi University, said.Together, these 11 wetlands, being created on a stretch spanning three kilometers -- from Kilokri to Batla House -- on the floodplains will treat around 1,500 MLD of sewage from around 25 drains that pollute the Yamuna.

The Delhi Development Authority and a team of experts from Delhi University have created a constructed wetland, the first among 11 such ecosystems being built on the Yamuna floodplains near Kalindi Kunj, to naturally treat around 15-20 million litres of sewage a day. Currently, the wastewater from several unauthorised colonies goes into the existing natural wetlands that clean it “very marginally” before it enters the Yamuna.

A constructed wetland is similar to a natural wetland but is engineered for efficient treatment of sewage. “The constructed wetland has been created using just boulders and plants,” Prof C R Babu, who heads the Centre for Environmental Management of Degraded Ecosystems (CEMDE) at Delhi University, said.

Together, these 11 wetlands, being created on a stretch spanning three kilometers -- from Kilokri to Batla House -- on the floodplains will treat around 1,500 MLD of sewage from around 25 drains that pollute the Yamuna. Maharani Bagh drain is the largest of these drains. It carries around 250-500 MLD wastewater.

The first constructed wetland near Kalindi Colony was inaugurated on Friday. It treats around 15-20 MLD of sewage from the nearby areas, officials said. It has oxidation ponds, a gradient channel with a mesh and boulders acting as filters, ridges and furrows having 25 aquatic plants that feed on organic matter in the wastewater.

''These constructed wetlands are an alternative to conventional sewage treatment plants in Delhi, which are either underutilised or do not treat wastewater properly. The quality of water flowing out of these constructed wetlands will be similar to that of the Yamuna,” Prof Babu told PTI. The remaining constructed wetlands will be fully functional by mid-2021. These will treat the sewage from unauthorised colonies such as Taimoor Nagar, Khizrabad, Zakir Nagar and Batla House that go into the Yamuna directly, he said.

The constructed wetland ecosystem is part of 115-hectare South Biodiversity Park coming up underneath the Delhi-Noida Direct Flyway and near Kalindi Kunj. “We will plant more than 1 lakh saplings on the five kilometer-long embankment along the marginal bund and the islands we have created on the floodplains as part of the South Biodiversity Park,” Babu said.

The work to remove water hyacinths from the existing natural wetlands will start in December-end. Thereafter, it will be full of birds, said Yasir Arafat, a scientist who is part of the 12-member team headed by Babu. Wherever there are water hyacinths, the birds do not come as the invasive aquatic plant restricts birds' access to water, Babu explained.

The work on the South Biodiversity Park began in May last year. The project costs Rs 2.5 crore and is expected to be completed in around five years. The site, which is full of grass and water hyacinths, was being used as an illegal dump for construction debris and as an open defecation ground by slum dwellers, Arafat said.

A five-kilometer-long and seven feet high wall is being constructed along this floodplain area to prevent illegal activities, he added. 

(This story has not been edited by Devdiscourse staff and is auto-generated from a syndicated feed.)