Context:
Vembanad Lake, India’s longest and Kerala’s largest lake, is under serious ecological stress. Spanning 96.5 km and draining six major rivers, it supports agriculture, biodiversity, and livelihoods across Alappuzha, Kottayam, and Ernakulam. The lake is part of the Vembanad-Kol wetland system, a Ramsar site, but has shrunk drastically due to human encroachment, pollution, and weed infestation.
Key Environmental Challenges
Shrinking Surface and Depth
- Surface area reduced by 27% between 1917 and 1990 (cited by multiple studies).
- Encroachment, land reclamation, sedimentation cited as major contributors.
- Lower floodwater retention and impaired ecosystem functions such as water purification and biodiversity support.
Pollution and Biodiversity Loss
- High levels of plastic waste, silt, and chemical pollutants found in recent studies.
- Water hyacinth proliferation contributes to elevated Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD).
- Fish catch down by 66% over three decades due to eutrophication and habitat degradation.
Unregulated Human Activities
- Houseboats identified as key pollutants.
- Unauthorised vessels and encroachments remain largely unchecked despite regulatory attempts.
Vembanad Lake Rejuvenation Project
Administrative Framework
- Spearheaded by Alappuzha District Collector Alex Varghese, inspired by Namami Gange.
- Backed by ₹188.25 crore five-year plan, submitted to CM Pinarayi Vijayan.
- Guided by 8 subcommittees covering agriculture, fisheries, sanitation, biodiversity, climate change, and more.
Short-Term Objectives
- Removal of plastic waste and water hyacinth.
- Construction of 31 bio-bunds (1 km each) across grama panchayats.
- Fish ranching and bio-shield installation to protect farmland.
Long-Term Targets
- Dredging lake bed to improve water-holding capacity.
- Promotion of organic farming to reduce pesticide runoff.
- Establishment of sewage and faecal sludge treatment plants in flood-prone Kuttanad.
- Utilisation of water hyacinth for value-added products.
- Boosting sustainable tourism and fisheries.
Progress So Far
- 28.72 tonnes of plastic waste removed, along with large volumes of weeds in district-led cleanup drives.
Challenges Ahead
- Political will required to reclaim encroached land.
- Enforcement needed against illegal houseboat operations.
- Integration with broader Kuttanad region revival essential due to ecological interdependence.
- Need for inter-governmental collaboration and local community engagement for sustainable outcomes.
