Gabion Walls Shield Seven Islands at Ranganathittu Bird Sanctuary from Erosion
To prevent soil erosion, authorities have installed Gabion walls around seven islands at the Ranganathittu Bird Sanctuary. Funded by the NHAI as a wildlife mitigation measure, the project secures these habitats against flooding from the KRS reservoir, ensuring long-term ecological stability.
Highlights
- •Seven vulnerable islands at Ranganathittu Bird Sanctuary are now protected by new Gabion walls.
- •The initiative aims to prevent soil erosion caused by water discharge from the KRS reservoir.
- •Previous attempts using sandbags failed due to interference from crocodiles and seasonal flooding.
- •The NHAI funded the construction as a key wildlife mitigation measure for the nearby highway project.
In an effort to curb environmental degradation, authorities have installed protective Gabion walls to shield seven vulnerable islands located within the Ranganathittu Bird Sanctuary. These islands had been facing a persistent threat from soil erosion, primarily due to heavy water discharge from the Krishnaraja Sagar (KRS) reservoir, which is situated approximately 10 kilometers upstream in Srirangapatna taluk, Mandya. Given the ecological significance of the sanctuary, securing these landmasses has become a priority to prevent them from being washed away during seasonal flooding.
Enhancing Island Stability with Gabion Walls
The implementation of these structural barriers follows a successful pilot project where officials tested the placement of stones around one of the islands. Observations confirmed that this technique effectively mitigated soil erosion even during periods of high water release from the reservoir. Encouraged by these results, the Mysuru Wildlife Division decided to scale the initiative to cover seven of the most flood-prone islands out of the 26 located within the sanctuary. Previous attempts to protect the riverbanks using sandbags proved unsuccessful, as they were frequently compromised by the movement of local wildlife, particularly crocodiles that climb onto the banks and damage the barriers with their sharp claws.
The project received essential funding from the National Highways Authority of India (NHAI) as a wildlife mitigation measure. The support was tied to the ongoing development of the Kushalanagar-Bengaluru Highway, which runs approximately one kilometer from the protected area. By integrating these Gabion walls into the landscape, the authorities aim to balance infrastructure development with necessary environmental conservation efforts.
According to Prabhugouda Patil, Deputy Conservator of Forests for the Mysuru Wildlife Division, the durability of these structures is a significant advantage. The newly installed Gabion walls are designed to last for approximately 40 years, providing long-term stabilization for the soil while ensuring that the root systems of the island’s trees remain undisturbed and intact. Beyond the technical benefits of soil retention and flood protection, officials have noted that the structures have harmonized well with the surrounding environment, preserving and even enhancing the natural aesthetics of the Ranganathittu Bird Sanctuary. This initiative stands as a testament to how targeted engineering can effectively address the challenges posed by extreme water levels and erosion in ecologically sensitive zones, ultimately safeguarding the habitats of the many bird species that rely on these islands for nesting and survival.
