Once a stormwater drain, now an open sewer

The Grand Canal, running through the Boulevard, has degraded as a result of mismanagement and rapid urbanisation

Architectural landmark: The Grand Canal in Puducherry was built as a stormwater drain by the French around 1765.

Cutting through the Boulevard, the Grand Canal, an architectural landmark was once a stormwater drain that channelised the water of Uppar river to the west of the town.

Constructed for the purpose of discharging the run-off during the monsoon into the sea, the Grand Canal has now degraded due to inflow of sewage and rampant encroachments.

“The Grand Canal was built as a stormwater drain by the French around 1765. It was designed to regulate the flow of rainwater towards the north-end into the Uppar drainage and to the south into the sea near the New Light House,” an urban planner said.

“Gradually, the Grand Canal has become a sewage line in the heart of town, with the waste water getting choked before it reaches the Uppar drain. A long stretch of the canal was covered about 20 years ago. Now it is being used as a dumpyard, parking space for vehicles and as a space for local market,” the urban planner said.

The local body also did not attach much importance to proper maintenance of the canal, and it remains clogged with plastic and paper waste on the southern end. Raw sewage from homes and commercial establishments continues to drain into the canal from multiple entry points, officials said. A survey by the Indian National Trust for Art and Cultural Heritage (INTACH) revealed that around 250 houses were letting their waste into the drain.

According to an official, “the unplanned boom in residential and commercial buildings has led to the flow of sewage water into the canal. It is difficult to clear the encroachments on the stormwater drain unless a policy is drafted by the government. In the absence of a full-fledged drainage system, it is difficult to prevent the raw sewage from entering the canal.”

Underground drainage

An underground drainage system was constructed in 1979 and designed for a population of 117,000 as per the City Development Plan. However, due to the insufficient carrying capacity of the sewer, the manholes began overflowing onto the roads before reaching the Grand Canal through the side drains. As a result the stormwater rain has become the biggest casualty, carrying only contaminated water, a report explained.

According to S. Nadarajan, a resident of Ambalathadayar Madam Street, “The Grand Canal was designed in such a way that it had three sluices on the seashore to regulate the entry of sea water into the canal for cleaning. But now the sluices themselves have either been removed or damaged. The covering of the Grand Canal with concrete structures should not have been permitted because it obstructed the flow of sewage. The government must have a another look at the structure and understand the purpose for which the canal was created.”