India Currents, in collaboration with bioGraphic and the California Academy of Sciences, is publishing the last in a 3 part series on Chennai’s restoration of its marshlands. Read Part 1 and Part 2 of this story!
(Featured Image: Mylapore Tank holds water even during the dry season, but only because its bottom has been paved over.)
Temple tanks
As in most Indian cities, Chennai’s piped water supply is available for just a few hours a day. And many parts of the city have no water connection at all. So many people pump groundwater, either on their own property or from government wells on the street. Others hire tanker trucks to fill their cisterns with water that has also been extracted from underground. “A huge quantity, almost 200 MLD [million liters daily] of water, is being shipped every day,” a water utility official told me. But surface and groundwater are not separate sources; they are linked by gravity and hydraulic pressure. So when people pump groundwater, they are ultimately depleting surface water as well, and near the coast, they are turning their water salty.
With little monitoring and few restrictions, the city’s groundwater table is dropping by some 10 to 20 centimeters (4 to 8 inches) every year. That’s why finding creative ways to recharge groundwater within the dense, paved city is a critical step toward having enough water for people and for nature. And that’s where many small projects come into play. Recharge wells are becoming more common around neighborhoods in Chennai, their round perforated covers, a little larger than manholes, pocking city streets and sidewalks. Those covers lead to wells averaging 4.5 meters (15 feet) deep that simply give water a path into the permeable subsurface, and eventually into the aquifer.
Through water as leverage, Madras Terrace, a local architecture firm, has proposed another approach to getting water into the ground across the city: temple tanks, a remnant of the eris system. In the past, “you cannot find a village without a temple, and you cannot find a temple without a water body,” says KK. Lots of those villages and temples have now been subsumed by the city.
One bright, blue-sky day, just before I leave India, I meet with Sudhee NK, an engineer and financial planner with Madras Terrace. We rendezvous in charming, bustling Mylapore, a neighborhood centered around Kapaleeswarar Temple, marked by a 37-meter-high (120-foot-high), pyramidal tower intricately carved and painted with some of Hinduism’s more than 3,000 gods. Vendors sell flower offerings, clay cups meant to be broken after drinking, and small deities. One of Chennai’s most notable tanks, occupying a city block, sits alongside the temple. With its top at street level, an inverted, stepped pyramid descends into the ground so people can continue to access water as the table falls.
Sudhee explains that, historically, the tank bottoms were unpaved so that groundwater replenished the tank from below, and rain and runoff from above helped to recharge the water table. Temple tanks were connected to larger eris systems and also served ritual purposes. Today the Kapaleeswarar tank holds water—ducks swim along the side and turtles bask in the sun—but only because the bottom was paved about 10 years ago to retain water for religious ceremonies. This water is effectively a mirage, says Sudhee.
To show me the true status of the water table here, he leads me across the street to another temple tank, Chitrakulam Pond, believed to be more than 2,000 years old and not cemented. Its bottom is carpeted with a mat of fresh grass, sprouted from recent rains, but the water has descended deep underground. “This is the real situation,” says Sudhee. Too much pavement and too many borewells are to blame for water levels more than 18 meters (60 feet) below the surface, he says.
Sudhee and colleagues want to restore temple tanks across Chennai to their natural, unpaved state, to move water underground. The city government, Greater Chennai Corporation (GCC), is connecting stormwater drains to temple tanks wherever possible to allow for groundwater recharge. And Sudhee’s team is also helping to raise the water table by collecting rainwater from buildings via vegetated ditches, called bioswales, placed strategically along streets, on hotel properties, in backyards, and in schoolyards. The Mylapore project is expected to provide on average 4 million liters (1 million gallons) of water per day. Replicating the project across 53 other temple tanks in Chennai could result in 60 million liters (16 million gallons) per day of recharge, according to the Water as Leverage team’s projections.
Reconnecting with culture
Despite stated government support for these slow water projects, getting utility engineers to embrace green solutions is difficult, says Balaji Narasimhan, the hydrologic engineer who is also involved in the Dutch-local partnership. That’s in part because the systems are more complex than concrete-lined drainage channels, levees, and dams. Slow water projects usually have a biological component, such as plants that may require soil amendments to achieve the chemistry or filtration they need. Silt traps must be cleaned. Also, because such projects tend to cover a larger area than concrete solutions, the public is more likely to come in contact with them, so project managers need to cultivate community support. But that requirement can be a benefit, says Narasimhan, reconnecting people with their water.
KK tells me, “Even 200 years ago, people used to worship rivers as goddesses. Because of that, we were preserving water. Now we’ve lost those cultural values; we forgot.” When water “magically” arrived via centralized distribution, people stopped caring for their water bodies. In North Chennai, parts of which remain somewhat rural, Jayaraman, the activist, has witnessed that loss in a single generation. “Among the older people, there is a far more intimate knowledge of hydrology, of seasons,” he says. “Among the younger people, that is eroding quite quickly. It erodes with the landscape. Your culture goes with the landscape.”
But the reverse may also be true. As government agencies and NGOs hold and reclaim space to reestablish slow water, and as people harvest some of their personal water from local supplies, Narasimhan says he hopes they will become newly motivated to keep them clean and replenished.
One project is directly targeting the next generation. On a warm, partially overcast day in early December, I grab an autorickshaw to Tholkappia Poonga Eco-Park, a 24-hectare (58-acre) green oasis in the heart of the city, near the mouth of the Adyar River, which bisects Chennai. Separated from the beeping traffic outside by concrete walls, the tree canopy is thick here, and the peaceful walking paths and the air above are bustling with butterflies, beetles, blue-and-yellow grasshoppers, crane flies, lizards, lorikeets, and other birds.
Years ago, an area creek feeding the river was filled in for development and this place became a dump, piled high with garbage and human waste and used for illegal activities. To counteract pollution and biodiversity loss, local NGO Pitchandilkulam Forest Consultants and city agency Chennai River Restoration Trust began restoring the area’s former river and estuary habitats 12 years ago.
My guide during this visit is K. Ilangovan, an ecologist and wetlands specialist who has overseen this project from the beginning and has himself planted thousands of trees, including mangroves and 250 other species of plants. Since forest restoration here began, he’s observed snakes, mongooses, mice, and even jackals that feed on crabs and fishes. “We didn’t introduce anything here,” he says. After the replantings, “everything came.”
People from nearby neighborhoods were involved in the planning and planting so that they would better understand the area’s purpose, and some still have jobs here taking care of the plants. During the monsoon, the whole park becomes flooded, storing water, says Ilangovan, and the surrounding neighborhoods have seen higher water levels in wells and reduced flooding, including during 2015, when they were spared the worst of the flood. The microclimate has also changed, keeping it a little cooler than the concrete jungle elsewhere in the city. The third phase of restoration is now underway; ultimately 145 hectares (358 acres) will be restored.
Aside from offering homes to a variety of creatures in the middle of the city and mitigating water problems, the Eco-Park is a favorite field trip destination for school children, who come here and are blown away, says Ilangovan. Living in the city with little exposure to nature, “They are so happy to touch and feel the plants. You can see the brightness in their faces.” That outreach is critical to changing the direction of society, he says. “We can’t go and change the people with 40 or 50 years’ age,” he says. “So I focus more on the kids.”
Amidst growing environmental awareness of the general public and the government, four of the seven projects proposed by the Dutch-local partnership are moving forward, says Jayshree Vencatesan, including the Mylapore tank and Muttukadu Backwaters. Separately, her nomination of Pallikaranai as a Ramsar site, a wetland of international importance, is under consideration by the central government in Delhi. But development pressure remains intense. “We as a country are trying to become more of a wealthy nation,” says Vencatesan. “And if we assume that people don’t want that, we are wrong.”
Back at Pallikaranai Marsh, walking down a muddy path at the edge of shallow open water, we pass trees planted by Care Earth Trust, trunks wrapped in cuttings of an unpalatable plant to deter nibbling cattle. Bee-eaters and kingfishers whiz by, and a fan-throated lizard darts under a rock. The sun glints off an iridescent green jewel beetle with black spots, bumpily navigating stems and leaves. Antennae waving about, it suddenly flips, revealing a bright orange undercarriage. There’s still plenty to amaze here.
Educating people about the value of water systems and biodiversity is a long-term process, says Vencatesan, one that she’s been working toward with her characteristic persistence for decades. Near the spot where I was stuck in the minivan, she is planning to reroute traffic away from the marsh and build a pedestrian “ribbon walk,” where people can interface with nature. “They should see a value in it,” she says. “Otherwise, it’s not going to last.”
Go back and read Part 1 and Part 2 of this story!
Erica Gies is an independent journalist who covers science and the environment from Victoria, British Columbia, and San Francisco, California. Her work appears in the New York Times, Scientific American, Nature, Ensia, The Economist, bioGraphic, National Geographic, and other outlets.
Photographs by Dhritiman Mukherjee.
This story originally appeared in bioGraphic, an online magazine about nature and sustainability powered by the California Academy of Sciences.