Polluted stream water entering Flamingo Lake DPS is a threat to Navi Mumbai wetlands: study
Flamingos seen at DPS lake in Nerul, Navi Mumbai. File | Photo credit: Emmanual Yogini
The latest test commissioned by the Navi Mumbai Environment Preservation Society and NatConnect Foundation shows alarming levels of contamination from the intertidal channel, raising fresh concerns over the sharp decline in flamingo sightings in the Navi Mumbai wetland this season.
The test suggests total dissolved solids (TDS) at 19,600 mg/l — more than nine times the permissible limit of 2,100 mg/l as per IS 2490:1974 norms for inland surface water. This suggests that the polluted water in the creek entering the Flamingo Lake DPS is a threat to one of Navi Mumbai’s most important wetlands, which forms part of the Ramsar-listed Thane Creek Flamingo Sanctuary ecosystem.
“The toxic mix of polluted tides and extensive blue-green algae appears to have pushed the Flamingo Lake DPS to an ecological tipping point,” said NatConnect Foundation director BN Kumar, adding that there is an urgent need to speed up the final government resolution granting Flamingo Lake DPS sanctuary status and ensure stronger legal protections.
The findings reinforce concerns raised by earlier tests commissioned by NatConnect. A sample taken from the lake in March recorded TDS at an alarming 21,720 mg/l, while the drainage discharged into the wetland showed TDS values of 7,950 mg/l in April. The April sample also recorded a biochemical oxygen demand (BOD) of 36.4 mg/l, exceeding the permissible limit. All three samples did not meet inland water quality standards.
“Flamingos can tolerate natural salinity, but cannot thrive in waters containing a cocktail of sewage, urban runoff and other contaminants. Deteriorating water quality is constantly disrupting the lake’s ecological balance and reducing its food base,” said Navi Mumbai Environment Preservation Society representative Sandeep Sareen.
Scientific studies, including research published in Nature Geoscience, have highlighted the long-term risks of changing estuarine hydrology and have shown that human interventions in tidal systems can create feedback loops that amplify ecological stress by affecting water quality, sediment dynamics and biodiversity. For Navi Mumbai, the declining number of flamingos at the DPS lake is more than the loss of a seasonal attraction. It’s an early warning that one of the region’s most fragile wetlands is under increasing stress.
The findings at the Flamingo Lake DPS reflect broader global concerns. In its report Wetlands: The Unsung Heroes of the Planet, the UNEP-DHI Center for Water and Environment warned that wetland loss has accelerated since 2000, with pollution, habitat degradation and unsustainable human activity causing a rapid decline in wetland-dependent species.
Flamingos are particularly vulnerable because they depend on a narrow range of water chemistry and salinity conditions that sustain the algae, diatoms and microscopic invertebrates that make up their food base.
Published – 23 Jun 2026 08:43 IST