Local residents and environmental workers warn that this dirty water creates a huge risk of severe flooding before the rainy season starts. At the same time, it causes heavy damage to the delicate natural environment and wildlife area at Ennore Creek.

Residents and Activists Raise Alarm Over Monsoon Risks

The illegal sewage discharge into the Buckingham Canal has raised deep concerns among local residents who have previously suffered from severe urban flooding.

The residents complain that when the area was hit by monsoon few years back water overflowed from the canal and inundated 2nd, 3rd, 4th, 5th, 6th, and several other streets in Nethaji Nagar. Waist-level sewage water was recorded in low-lying areas, along with knee-level flooding.

Beyond the immediate neighborhood, environmental advocacy groups point out the wider ecological impact on Chennai’s drainage networks and coastal wetlands.

The untreated sewage carried by the canal eventually flows downstream and settles in the wetlands of Ennore Creek. Thick sewage mud collects at the river mouth, harming sea life and blocking the natural flow of water, which makes storm water drain away much slower across the whole city.

What Steps Are Authorities Taking to Resolve the Issue?

In response to growing public concern, local water supply and civic authorities have outlined targeted infrastructure measures to contain the pollution and restore normal canal flow:

• F4 Sewage Pumping Station Pipeline Upgrade: Metro Water is actively replacing the high-capacity 1,000 mm sewage pipeline connected to the F4 sewage pumping station in Tondiarpet.
• October Completion Deadline: The remaining 160 meters of pipeline replacement work is scheduled for completion by October 2026.
• Plugging and Redirection to Kodungaiyur: Once the new pipe is ready, workers will block the open pipe leading into the canal. All sewage will go to the Kodungaiyur Sewage Treatment Plant to be cleaned properly.
• Cleaning Out the Canal: City workers are also clearing out mud, trash, and floating weeds from the canal bed so rainwater can flow faster without backing up into streets.

Conclusion

Fixing the illegal sewage outfall in the Buckingham Canal is urgent for the safety and health of Tondiarpet residents. Plugging the illegal pipe, finishing the pipeline replacement by October 2026, and cleaning out accumulated silt will help prevent severe street flooding and protect the delicate environment at Ennore Creek. Completing these projects on time is crucial to keep local communities safe and ensure rainwater can drain freely when the monsoons arrive.

The proposed Uthandi flood canal is a ₹91 crore infrastructure project planned by Tamil Nadu’s Water Resources Department (WRD) to mitigate flooding in South Chennai.

• Type: Underground “cut-and-cover” canal
• Length: Approx. 1–1.2 km
• Route: From Buckingham Canal (near Indian Maritime University, ECR) → through Uthandi → Bay of Bengal
• Purpose: Divert excess floodwater directly into the sea

Why is it needed?

Chennai’s drainage system is under pressure:

• Buckingham Canal capacity: ~7,100 cusecs
• Flood inflow during monsoon: ~8,000+ cusecs

This excess leads to flooding in:

• Velachery
• Perungudi
• OMR IT Corridor

👉 The canal is designed as a fast evacuation outlet to reduce water stagnation.

⚠️ Key Concerns Raised by Residents and Experts

1. Groundwater Contamination Risk

Residents fear that the canal may carry:

• Sewage inflow
• Urban runoff (oil, waste, chemicals)

This could result in:

• Pollution of groundwater aquifers
• Salinity intrusion in coastal wells

2. Coastal Ecosystem Damage

The proposed discharge point is near sensitive coastal zones, including:

• Turtle nesting areas (Olive Ridley)
• Intertidal ecosystems
• Coastal biodiversity zones

Potential impacts:

• Habitat destruction
• Beach erosion
• Marine pollution

3. CRZ Violations and Legal Issues

The project alignment reportedly intersects:

• CRZ-II (developed areas)
• CRZ-I (ecologically sensitive zones)

Concerns include:

• Lack of initial CRZ clearance
• Possible violation of coastal protection norms
• Risk of legal challenges

4. High-Volume Polluted Discharge

• Independent testing shows Buckingham Canal water is already highly contaminated
• Contaminants include:
  • Elevated faecal coliform levels
  • Biochemical Oxygen Demand (BOD) exceeding permissible limits
• Residents highlight that the proposed canal route passes through sandy, porous soil
• Such terrain increases the risk of pollutant seepage into groundwater
• This could lead to long-term or permanent contamination of drinking water sources

Moreover it is estimated that there is likely to be a discharge of:

• ~550 cusecs (≈15,500 litres per second) of water from the Buckingham Canal.

So the residents fear this may include the untreated or partially treated wastewater.

👉 This raises the concern that the canal could function as a:
stormwater + sewage outfall system

5. Impact on Fishing Communities

Local fishing hamlets particularly in Nainarkuppam have raised concerns about:

• Decline in fish population
• Pollution of near-shore fishing zones
• Loss of livelihood

This introduces a direct socio-economic impact, not just environmental.

6. Engineering and Sustainability Concerns

Experts have questioned the long-term viability:

• Underground canals are difficult to maintain
• Risk of clogging and reduced efficiency
• May become ineffective over time

🧭 Lack of Transparency & Public Consultation

Residents have highlighted:

• Limited disclosure of project details
• No clear publicly available alignment map
• Insufficient stakeholder consultation

👉 This creates potential procedural and legal vulnerabilities.

📩 Escalation and Public Opposition

The issue has moved beyond informal concerns:

• Petitions submitted to authorities
• Complaints escalated to regulatory bodies
• Organized resistance from:
  • Resident welfare associations
  • Coastal communities

👉 This is now a civic and governance issue, not just technical.

🌧️ Is the Canal Necessary in Uthandi?

A key argument raised:

• Uthandi itself is not a major flood-prone area
• The canal is designed to solve flooding elsewhere

👉 Interpretation:

• Flood burden from upstream areas is being shifted to a coastal zone

👉 The Bigger Urban Planning Problem

The project reflects deeper systemic issues in Chennai:

• Shrinking of Pallikaranai marsh
• Encroachment of natural waterways
• Rapid urbanisation in IT corridors
• Overloaded drainage infrastructure

👉 The canal addresses symptoms, not root causes

⚖️ Government’s Position

Authorities maintain that the project will:

• Reduce flood duration significantly
• Improve drainage efficiency
• Provide faster water evacuation during monsoon

They also claim:

• Environmental impact will be minimal
• Studies are being conducted

📊 Balanced Evaluation

✔ Potential Benefits

• Faster flood drainage
• Reduced urban waterlogging
• Protection for high-value IT corridor zones

❌ Risks

• Groundwater contamination
• Coastal ecosystem damage
• CRZ violations
• Livelihood disruption
• Legal challenges
• Short-term solution to a long-term problem

📌 Final Takeaway

The Uthandi flood canal project represents a critical urban dilemma:

Immediate flood relief vs long-term environmental and social sustainability

If implemented without strong safeguards, it could:

• Solve flooding temporarily
• But create lasting ecological and groundwater damage