From Mullaperiyar dam to sand mining: A history of the slow death of Kerala’s rivers

Kerala, rich with waterbodies, has been mourning the slow death of its many rivers, lakes and canals over the years, with environmentalists making desperate calls to save what’s left.
A waterbody in Kerala
A waterbody in Kerala
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Hundred and twenty-six years ago, a British civil engineer called John Pennycuick constructed a dam in India that would take water from the longest river in Kerala to a district in nearby Tamil Nadu. Built on the Mullaperiyar, one of the tributaries of the great river Periyar, the dam diverted water to Dindigul for agricultural purposes. A contract was duly signed between the two states – one under the control of the King of Travancore then, and the other under the Madras Province of the government of India. The lease was signed for 999 years.

In the many decades that have passed, more dams were built and hydroelectric projects developed, until a day came when most of the water upstream of the Periyar got diverted and the river was deprived of downstream water. Dams are of course only one of the reasons for the deterioration and Periyar only one of the rivers that suffered such a fate in Kerala.

With World Water Week observed from August 23 to 27 with the theme ‘Building Resilience Faster’, it’s time to revisit some history to understand what led to this sad state of affairs. Kerala, rich with waterbodies, has been mourning the slow death of its many rivers, lakes and canals over the years, with environmentalists making desperate calls to save what’s left and to revive resources.


Mullaperiyar Dam / Credit - Bipinkdas / Malayalam Wikipedia

“That’s how we started the page ‘Waterbodies – Destiny of Them and Us!!’ on Facebook. To bring awareness about the state of our waterbodies and about how people have contributed to it over the years,” says environmentalist Veena Maruthoor.

It wasn’t like this 50 years ago, she says. Back then we left our forests and water resources alone. Summers were not so intense and water in the wells did not dry up soon after the rainy season was over.

“And then came the plantations. They couldn’t hold water like forests did. So all the rain water would rush to the sea. Water rose to unusual levels in rivers and we faced floods. In summer, we were left dry. But forests hold water like a sponge and release it little by little into streams when it’s summer. Laterite hills help too. More than 40% of the rain water is held by laterite hills. Where there are lots of trees and humus, it will be porous, and the pores can hold water,” Veena explains.

Periyar, a case study

There are 44 rivers in the state and only three of them flow eastward. The rest flow west. Periyar, 5,000 odd square kilometres in area and 260 km in length, flows west. It passes through cultural centres of the state, through the Sivarathri celebrations in Aluva, through the church celebrations in Malayattoor and to the oldest mosque (Cheraman Juma Mosque) at the mouth of the river.


Periyar / Credit - Jithin Alias / Wiki Commons

Back at the time Pennycuick built the Mullaperiyar dam, he wanted to create a harmonious atmosphere in the east coast by taking the water there and have people cultivate crops. “It was tough. Remember there were no mechanical means then – no lorries, no cranes, no means of transport. People had to work hard under the sun. And to make them work, Pennycuick gave them liquor,” says EJ James, hydrologist and water resources engineer.

The British man didn’t give up when they ran out of government funds for the dam construction. He went to England, sold his property, raised the money and came back to complete the dam. It is an engineering miracle, concedes James, and it helped agriculturists.

But then it caused a lot of issues between the two states of Kerala and Tamil Nadu, and the Supreme Court formed a committee that decided the height up to which the dam can be filled.

“The dam resulted in the formation of a big lake – the Periyar Lake. People call it the Thekkady Wildlife Sanctuary. The lake created biodiversity and animals moved about the area. An eco-system was developed, which was duly appreciated by the United Nations,” James says.

But as years passed and India gained independence, the river was further exploited. Hydroelectric projects were built. Pallivasal is believed to be the first in the area. Other small projects were set up too. Then a large one was built – the arch dam of Idukki – with the financial and technical support of the government of Canada. It could store a large quantity of water available in the catchment upstream minus the water that went to Mullaperiyar, and support a 780 MW power station in Moolamattom.


Idukki Dam / Credit - KSEB / Wiki Commons

It was a tribal person who discovered the possibility of such a dam between the Kuravan and Kurathi hills, says James. The Idukki dam took water to Muvattupuzha, creating yet another diversion for the west flowing Periyar to change its tack and turn east. “Then they thought of another dam in Muvattupuzha, and the Malankara Dam was built to irrigate some areas in the river basin. The water then flowed towards the Vembanad backwaters. But this brought more freshwater to Vembanad and adversely affected the life of fishes,” James says.

The dams didn’t stop, of course. Idamalayar dam too was built for more hydroelectric power generation. James says Kerala just didn’t have another source for power generation. The Parambikulam-Aliyar project diverted water from the Periyar, Chalakudy and Bharatapuzha rivers in Kerala eastward to Tamil Nadu for power generation, irrigation and drinking water purposes.

All the dams and all the diversion of water reduced Periyar to the poor state it is in now.

Industries and sand mining

The cropping up of industries and the discharge of industrial waste famously polluted river after river. Periyar again became a major casualty with a bulk of Kerala’s industries coming up on its banks. “One day some managers in some of these industries decided that they will build bunds in the river. And your sacred Periyar became a lake! The three barrages they constructed made it a summer season lake but when monsoon came, it would be cut off and sediment in the river,” James says.

Sand mining became another major contributor to further deepening of rivers. “In a sand audit conducted in 2013 in the Chalakudy river, it was found that while the surface water level went down in some areas the river bed under it had lowered by 10 to 12 metres,” says SP Ravi, director of River Research Centre (RRC), Chalakudy.


Chalakudy River / Credit - Jan J George / Wiki Commons

Ravi and others at the RRC have been working on the revival of the Chalakudy river. He figures that the deterioration of the Chalakudy and other rivers became obvious about 40 to 50 years ago, but the causes had emerged even before that. “Now we don’t even have 10% of the summer flow that we had in the 1940s in River Chalakudy. After the 1970s, there began large-scale commercial sand extraction from rivers. The water table of rivers in midland regions lessened by three to four metres in 10 to 20 years. This caused the groundwater level of neighbouring areas to also go down,” Ravi says.

He connects it directly to the decline of paddy fields. “In 1971 we had the most number of paddy fields – 8.8 lakh hectares. Over the next few decades, this has reduced to 2 lakh hectares.”

It was in 1983 that Kerala had the first state-wide drought, Ravi recalls. It happened a few more times before 2000. “But after the continuous droughts of 2003-2004, however much rain we got there would be no water during the summer,” he says.

When plantations grew and replaced forests in many parts of the state, they brought pesticides with them, sprayed on the tea and pepper and cardamom. These too flowed to the rivers, says Zabna, coordinator of RRC’s Schools for River project. She speaks of the Pamba Action Plan that was launched to end pollution in River Pamba and the other measures in controlling what reaches the waterbodies.


Industries along River Periyar

“There are rules in place – such as the Water Act – but they are not followed. Only if we follow a holistic approach can we solve this. But as long as people are not worried about the condition, as long as they have other means of water and aren’t personally affected – this will prove difficult,” Zabna says.

Human contribution

The dams and the deforestation and the industrial waste apart, humans also have a more direct role to play in the deterioration of waterbodies, namely the plastic and other waste we throw into ponds and rivers, the sand we dig out from riverbeds and sell for money.

“What happened to the ponds? I remember there were three just around my house when I was growing up (in Thiruvananthapuram). Now they are all gone. People filled up ponds thinking that lands are an asset," says Veena.


Residents clean up Vellayani Lake

She remembers canals dug parallel to streams where big fishes swam and water plants grew. “These plants like the water hyacinth have cleaning properties. That’s one reason we see water hyacinths in Vellayani Lake. It is because it is so polluted that the plants come up,” she adds.

If you ask the people who have watched the slow destruction of a river, they can tell you old stories of glory days. Like how in Thiruvananthapuram’s Parvathy Puthanar river, children once used to throw coins because you could see it shining at the bottom, the water used to be that clear. Not anymore.

After the devastating floods of 2018, people in Kerala began speaking about the need to conserve the water resources. “We talked about how if the intensity of the rains was high, it would go towards the sea – for every raindrop eventually goes home to sea. But to slow down its movement, we had to bring back the marsh lands. However, the discussion died down in the last two years when we didn’t receive scary rainfall like in the previous years. But we must restart those discussions. We need a water literacy programme. When we destroy a hill, we don’t think of the water table. There will be a valley beneath that hill, a stream starting from it. And when we add pollutants to the water, it is like injecting poison into blood,” Veena says.

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