Chennai wants to build stormwater drains on its beaches: Why this is a bad idea

“Stormwater drains are generally not necessary for these sandy coastal areas. Left open, these sands will soak up 40% of all rains that fall on it,” says Elango, an Anna University professor.
Why stormwater drains in beaches is a bad idea.
Why stormwater drains in beaches is a bad idea.
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Stormwater drains are the latest in a flood of bad ideas to plague the picturesque coastline of South Chennai. Residents along East Coast Road (ECR) have opposed Greater Chennai Corporation’s network of structures draining 318 roads on the sandy beaches of the Kovalam sub-basin, east of the ECR. They have rightly alleged that the concrete underground drains are unnecessary, and are wasteful of public money and rainwater. But even their arguments fail to highlight that the under-construction Rs 300 crore project, financed by German government-owned development bank KfW, is illegal.

The project does not have a prior clearance under the Coastal Regulation Zone Notification. (Any project that has CRZ clearance would have been discussed at the State Coastal Zone Management Authority, and the discussion would be reflected in the meeting minutes. The GCC's SWD project in Kovalam basin is not discussed in any of the meetings.) Worse, this illegal project seeks to mitigate flooding – a problem caused in the first place by other illegal structures and roads constructed or condoned by the Corporation.

KfW prides itself in lending only to projects with “as great a sustainable impact as possible when it invests in environmental and climate protection...” Its website declares that it invests only in agencies that “comply with high environmental, social and governance standards.” 

The controversial drain project casts a shadow over KfW’s environmental and legal due diligence, and its claims to transparent functioning. None of the project documents that they say are essential, such as the Detailed Project Report (DPR) or the Environmental and Social Impact Assessment Reports, are in the public domain. The DPR is important because it would highlight the various licenses required for the project. The DPR for a similar SWD project in the coastal town of Thoothukudi, for instance, clearly states that CRZ clearance would be needed for the project. 

GCC’s track record of violating the law is nothing new. What is surprising is why and how a German bank allowed its money to be used for an unauthorised project with questionable benefits to the environment and local residents.

Surplus engineering; regulatory deficits

The Coastal Regulation Zone Notification is meant to protect the ecologically sensitive coastal region from environmentally damaging activities, by regulating development and setting caps on the extent and kinds of construction permitted within 500 metres of the High Tide Line. Stormwater drains are permissible activities under the CRZ Notification. However, such projects are required to carry out rapid Environmental Impact Assessments and obtain CRZ clearance before construction. The ongoing SWD project has no CRZ clearance. Had this been the first illegality in the region, its consequences may have been negligible. But this violation is merely the latest in a long list of grievous offences targeting this hydrologically sensitive aquifer recharge region.

In the early 1990s, when the East Coast Road was proposed, a spirited fight against the highway that this writer was a part of, warned that the project would trigger dense urbanisation on the sand dunes and accelerate seawater intrusion. Sand dunes soak in rainwater, recharge groundwater and mitigate salinity intrusion into the coastal aquifers. Constructions retard percolation and recharge, and more habitations means more groundwater pumping, leading to a net depletion of aquifers. The warnings were ignored.

According to a study by Anna University’s geology department, the built up area along the beach stretch from Adyar to Muttukadu increased from 14 sq km to 20 sq km, with the densest increase concentrated in the north between Thiruvanmiyur and Injambakkam. The study, according to an article in The New Indian Express, cites estimates that 15,000 buildings in this stretch may have been built illegally without CRZ clearance.

According to Professor L Elango, a co-author of the Anna University study, the added construction would reduce annual recharge from 10 billion litres to 7.5 billion litres. The wasted potential alone would be sufficient to supply 70,000 people with 100 litres of water per day.

“Stormwater drains are generally not necessary for these sandy coastal areas. In fact, even pavements should be avoided in such areas. Left open, these sands will soak up 40% of all rains that fall on it,” says Elango.

A sustainable hydrological regime for this area can be facilitated by regulation that maximises open spaces, protects natural drainage courses and promotes regular maintenance and upkeep of natural drains.

In 2001, then Chief Minister Jayalalithaa made it mandatory for all buildings to harvest rainwater. If this law is sincerely implemented, run-off from the paved surfaces of buildings would not be able to reach the road. The only run-off that would need to be managed would be the road run-off. According to Elango, the sandy roadsides are sufficient to soak up road run-off.

Curiously, the Highways Department-owned ECR, which may be the only stretch that could have justified the use of some drainage infrastructure, is not covered in this project implemented by Greater Chennai Corporation. Rainwater run-off from ECR is likely to be highly contaminated with tyre residues, emission exhaust and oil. A drain to prevent this from percolating into a sensitive drinking water aquifer may have had some merit.

Building vulnerability

In a counter filed by the GCC, in the Madras High Court case challenging the SWDs, the Corporation has argued that dense urbanisation has rendered even this sandy region flood-prone. To support its contention, GCC says it placed JCBs and pumps at 80 locations between Kottivakkam and Uthandi during the 2015 to 2019 monsoon to “bailout rain water and also to cut kutcha drains at many places.”

GCC’s submission, though, fails to note that the only places where water had to be bailed out and where kutcha drains had to be cut were along the illegal coastal roads built by the Corporation, or elite busy-body walker associations. Several roads visited by this writer in the immediate aftermath of the floods had been excavated by local residents or GCC to facilitate the drainage of water into the sea.

In October 2015, the Coastal Resource Centre (CRC) published a review of illegal beach roads laid by GCC or local bodies between Muthukadu and Thiruvanmiyur. CRC found that GCC and local bodies had laid 5.8 km of roads made of asphalt, cement and construction debris in violation of the CRZ Notification. Seaside roads like Waterland Drive in Thiruvanmiyur, and the beach roads in Palavakkam, Kottivakkam and Neelankarai are all illegal under CRZ Notification and dangerous during the monsoons.

Unscrupulous property owners have taken advantage of the situation, and constructed buildings on the landward side of these illegal roads. They have availed of sanitation, water and other public infrastructure. This intensification of built-up space in the sensitive and vulnerable coastal area has harmed the hydrology, and robbed fisherfolk of their livelihood commons and space for their long-term housing.

The Chennai Metropolitan Development Area’s masterplan designates the lands overlaying the coastal aquifer as a recharge zone. Such areas must be safeguarded against dense urbanisation. But yielding to builder lobbies, the Government of Tamil Nadu has availed of the dilutions in CRZ Notification by the Union government to relax development norms along the coastal stretches up to Uthandi. Where once high-rise buildings were prohibited within 500 metres from the coast, new norms allow for development up to 50 metres from the high tide line.

What’s needed is not more concrete and buildings. The GCC needs to strictly enforce the law; it also needs to go beyond the law and cap urbanisation over the coastal aquifer. And it needs to aggressively keep the southern sands free of dense construction.

Meanwhile, German-inspired or not, the ongoing stormwater drain project promises to be yet another state-of-the-art hare-brained scheme that will cause more problems than it will cure.

Nityanand is a Chennai-based writer and social activist. Views expressed are the author’s own.

Main image courtesy: Destination8infinity, CC BY-SA 3.0, via Wikimedia Commons

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