While tributaries of Cauvery river have been abused by domestic, industrial and medical dumping to such an extent that it now stinks, water hyacinth is slowly strangling the Tungabhadra river. Its rapid growth has led to aquatic life facing a challenge to survive
BENGALURU/HUBBALLI: We know that both of Karnataka’s major rivers, Cauvery and Tungabhadra, have been sapped by unbridled growth and industrial pollution. But what is less known about these rivers is that they are not just overexploited along their banks, but also threatened at the very points of their origin in the Western Ghats which, despite receiving the highest rainfall in Karnataka, are unable to sustain the rivers that flow down their slopes.
For the past few years, several taluks in this rain-rich region and the primary catchment areas of rivers have been declared drought-hit. While the inflow of fresh water has diminished, the discharge of effluents from the industrial townships has only increased.
When the Indian Institute of Science researcher TV Ramachandra said two years ago that Bengaluru would become unlivable by 2020, he was denounced as an alarmist. But fellow researchers believe that the prognosis is dire enough even if 2020 does not spell Armageddon for Bengaluru. That’s a forecast for several other towns along Karnataka’s exhausted rivers. Some experts say the only way out is to look for hyper-local solutions. Or in other words, save the lakes and harvest the rain.
Karnataka’s most polluted rivers
Arkavathy
Bhadra
Bhima
Cauvery
Ghatprabha
Kabini
Kagina
Kali
Krishna
Lakshmantirtha
Malaprabha
Manjira
Shimsha
Tungabhadra
Source: National River Conservation Directorate
Saving the otters
Among the wildlife directly affected by the degradation of rivers are the otters. The part of Tungabhadra that flows through Hampi dividing Koppal and Ballari districts has been declared as India’s first otter sanctuary. The 34km long stretch is now a protected area for otters. But the dwindling fish count has affected its population. Indrajit Ghorpade of the Deccan Conservation Foundation says an action plan is required to manage the otter sanctuary. “The river is the lifeline of the two drie st districts. It’s important that the quality of water is restored. There have been attempts to use water hyacinth in making furniture and artifacts . We are looking at working with the Health Depar tment, district admins of Koppal and Ballari, Tungabhadra Board and Hampi World Heritage Area Management Authority to clean it up.”
The sorrowful situation of Vrishabhavathi river
Though discharge into rivers of domestic, medical and industrial waste i s seen along all riverside towns and cities, the situation is more pronoun ced along the Vrishabhavathi river, a tributary of Arkavathi, which in turn is a tributary of the Cauvery.
The stench is inescapable. Once a river, now it carries domestic, industrial and medical waste downstream, while local civic authorities fail to collect or treat waste. Once a river with potable water, it is now a gutter. The several lakes which fed the river during the rainy season have either been encroached upon or filled with sewage.
The Vrishabhavathi then joins the Arkavathy, a river that originates in Nandi Hills, and was once a source of water for Bengaluru when the Thippagondanahalli reservoir was built in 1935. A study by the Ashoka Trust for Research in Ecology and Environment revealed that the Arkavathy basin has dried up.
While climate change and check dams were initially blamed, the study by a team headed by Dr Sharachchandra Lele, blamed “overextraction of ground water by farmers and large-scale cultivation of water-intensive eucalyptus trees” to be the cause.
Though Cauvery has not suffered degradation to the extent suffered by the Vrishabhavathi — thanks perhaps to its sheer size — it too is no stranger to contamination. According to a study of the river and another tributary in Kabini, under the National River Conservation Project taken up by the Sri Jayachamarajendra College of Engineering of Mysuru, there was an exponential increase in coliform bacteria in water sources.
The study revealed ‘significant deterioration’ of the two water bodies. The total coliform (bacteria) per 100 ml of water had been in the 1,000-1,600 MPN (Most Probable Number) range in 1999. In 2013, it averaged more than 6,000 MPN at 18 monitoring stations along the rivers.
According to a Kodagu district Pollution Control Board officer, Ganeshan, the Cauvery’s water is unfit for direct consumption. It used to be good enough until a few years ago. “Some stretches of the river are severely polluted, even just kilometers from its source in Talacauvery,” he said.
MN Chandra Mohan, an environmental activist, said that if government does not take stringent measures, the Cauvery is bound to become another Ganga. TV Ramachandra, professor at the Center for Ecological Sciences, Indian Institute of Science, squarely blamed rapid contamination of water bodies on civic agencies that have failed to check pollution of water bodies and rampant encroachment of lakes.
The hyacinth choking Tungabhadra
In the case of the Tungabhadra, apart from pollution, water hyacinth, an invasive species, has decimated many stretches of the river. The growth of this weed has had an adverse effect on aquatic life, with fish population dwindling rapidly.
Shama Pawar, an entrepreneur from Anegundi, pointed out that the water hyacinth problem has become deep-rooted due to the absence of water flow from the dam for more than three years. “As there is prolonged drought there has been no water let out from the Tungabhadra dam. Earlier, the hyacinth would get washed downstream whenever the dam gates were opened. But now with drought its growth is just uncontrollable. It’s an eyeso re for tourists who come here from all parts of the world, and a big health hazard for the local people in Hampi and Anegundi,” she said. Increased use of pesticides in farms around the major rivers, discharge of untreated water from small and large industries, dumping of animal waste ha ve also affected the quality of water.
Ramachandra feels that the only way out is to encourage self-sufficiency of water needs of small communities. “Rather than making people become dependent on a source of water that is pumped from a station about 50 kilometres away, civic agencies should concentrate their efforts on reviving lakes and making the water in them potable. Extreme dependency on one water source is a recipe for disaster,” he added.