The Poonthangal lake is a crucial wetland ecosystem located in Kelambakkam near the Buckingham Canal. The lake is flanked by the Muttukadu backwaters to the east and the encroaching urban development to the west. The lake has been divided by the Anayka Bridge in recent years, which now extends over its eastern segment.

Once adorned with indigenous flora like Acacia Nilotica, the lake has fallen victim to environmental degradation. With the overgrowth of water hyacinth and sewage flowing from the nearby apartments, the lake was heavily contaminated. Due to an uneven terrain, the lake did not have a proper water holding structure. 

E.F.I had taken up the initiative to revive this water body and restore it back to its natural state. 

• Deweeding: Removing invasive weed species such as water hyacinth, Prosopis juliflora, Acacia alachnantha, Parthenium, Lantana camara and Corchorus olitorius from 3.4 acres of the lake’s surface has promoted the growth of native vegetation. With enhanced water quality, the lake supports a more balanced and diverse aquatic environment.

• Desilting: Desilting the lake to an average depth of 3-4 feet over 1.8 acres has enhanced water retention by removing accumulated silt and sediments. This process has improved the lake’s capacity to store water by increasing its effective volume.

• Dual Embankments: The construction of primary and secondary embankments—235 meters and 240 meters in length, respectively— has strengthened the structural integrity of Poonthangal Lake. These embankments help prevent erosion and ensure the long-term stability of the lake.

• Recharge Pit: A recharge pit has been constructed to enhance groundwater recharge, collect rainwater and allow it to percolate into the ground. This practice helps replenish the groundwater table, maintain water levels in the lake during dry seasons and support local water availability for both ecological and human needs.

• Nesting Islands: The creation of 21 nesting islands in Poonthangal Lake, which is situated near the Muttukadu backwaters has been a significant process as it acts as a crucial habitat for over 100 different bird species. These islands support avian biodiversity by offering safe nesting sites and contribute to the overall health and diversity of the local bird population.

• Trench Canal-  A 2-foot-deep trench canal was constructed along the bund to prevent sediment accumulation in specific areas of the lake. This trench canal provides essential surface drainage, allowing large volumes of water to be quickly directed into the lake. This drainage system is crucial for preventing flooding during monsoon seasons.

The revitalization of Poonthangal Lake has greatly benefited both the local community and wildlife. Improved water quality and stability, achieved through invasive weed removal, desilting, recharge pit and new embankments, have ensured steady water levels. The creation of 21 nesting islands has attracted a variety of bird species, thereby enhancing local biodiversity and fostering a rich ecosystem.

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