In the southern neighbourhood of Chennai city, the Ottiyambakkam Lake sits amidst an urbanizing area due to population growth. Numerous residential complexes in this vicinity rely on this lake as a water source. However, the lake has experienced significant alterations in land use due to evolving infrastructure and anthropological stress. 

With a lack of maintenance, the lake has become overrun by invasive weeds, spreading across its surface and embankments. The lake’s structural integrity has been compromised, resulting in weakened embankments. The absence of proper boundaries renders the lake susceptible to encroachment. Over time, silt deposition from runoff have led to a reduction in its water-holding capacity.

The Path to Restoration

A multi-pronged restoration effort by E.F.I has transformed Ottiyambakkam Lake back to its healthy, natural state. Here’s how:

• Deweeding & Garbage Removal : Invasive weeds such as Ipomoea carnea and Prosopis juliflora have been removed from the lake’s surface and embankments. Due to its close proximity to the residential area garbage dumping was a major problem, The entire foreshore region was cleared with garbage.

• Strengthening of Embankment:
  
  Break Bunds were constructed on the foreshore region using the silt removed during the cleaning process. These foreshore bunds act as a boundary for the lake, preventing encroachments and unwanted human interventions without restricting the flow of water.
  
  Dual Embankment was constructed on the offshore region of the lake with the silt excavated. This will improve the storage capacity and resilience during floods.
  

• Sedimentation Ponds & Recharge Pit: Two circular sedimentation ponds and a recharge pit have been made in the foreshore region of the lake. The sedimentary pits will allow the suspended particles in the inflow water to settle and ensure a smooth flow. The recharge pit will store water even during summer and improve groundwater recharge.

• Boundary Trench:  A boundary trench has been made as an excavation dug along the perimeter of the lake, the trench canal offers surface runoff to ensure that large volumes of water are drained quickly into the lake.

• Protective Fencing: Fencing has been installed around the foreshore of the lake. This will clearly define the boundaries and prevent future encroachments, ensuring the lake’s long-term health.

The Restoration of Ottiyambakkam Lake with all its new features such as enhanced embankments, deepened lake surface, sedimentation ponds, boundary trenches and protective fencing is monsoon ready.

Stay tuned in this space to learn more about E.F.I’s restoration activities in your neighborhood.

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