Anjaneya Reddy, a farmers’ activist from Chickballapur district, never thought that he would witness rivers in spate and tanks overflowing in his lifetime. And he’s not the only one shaking his head in bewilderment.
Heavy rains in October and November have brought rivers to life in the historically arid regions of Kolar, Chickballapur and surrounding areas. Six rivers that originate in the Nandi Hills range on Bengaluru’s outskirts are flowing bountifully, bringing much joy to communities living along the banks and despair to farmers who have lost their standing crops.
It had been years since the rivers — Arkavathi, Chitravathi, Papagni, Uttara Pinakini, Dakshina Pinakini and Palar — have been in spate like this, said locals and environmentalists. Barring Arkavathi, the other rivers are flowing after many years.
“I have never seen such a situation in at least 40 years,” said Mr. Reddy. “Kolar and Chickballapur districts are usually drought prone and farmers here practise rain-fed agriculture. I have only heard my grandfather recount stories of the six rivers and read about them in books,” he said.
From elation to despair
According to Chowdappa, an environmentalist, the excess rains in the Nandi Hills range had also filled up almost all the 5,000-odd tanks and lakes in the two districts. Most of the large tanks -- including Bethamangala, Kandavara, Amani Kere, Ramasamudra and Kolaramma tanks -- are overflowing, inundating bridges and flooding agricultural fields.
“The people, who initially celebrated the rains that filled up the dry tanks and water flowing in the rivers, have begun to despair at the damages that they have caused in the districts,” said Mr. Reddy.
Mr. Reddy, too, said it had been decades since the rivers flowed. Most parts of the catchment areas and canals have been encroached. “Now that they are in spate, the water is finding its old pathways, which have been encroached by fields and residential areas. This has naturally led to widespread crop damage and flooding — scenes we have not seen in our districts in this generation at least,” he said.
Irrigation expert Prof. N. Narasimhappa said because the lakes have not been desilted and the river basins not preserved, the districts will not be able to get the full benefit of these rains as the water retention capacity has reduced by a large measure.
“However, the groundwater table in the two districts will be recharged. Though farmers have suffered widespread crop damage this season, they will reap benefits over the next three to four years. All the borewells in the two districts will be recharged and farmers need not worry about water for at least a couple of years,” he said.
Following the flow of Arkavathi
Nirmala Gowda, Trustee, Bangalore Environment Trust, who recently led a team that followed the 92-km course of the Arkavathi till Sangama, said the river (Arkavathi) is in ‘flash flow’ in all the taluks following excess rains. This, she said, may last for around a week. “When we followed the river course, we found that full dams had to release large volumes of water, which had led to heavy soil erosion,” she said.
Series of bridges along the river’s course were inundated. “These bridges are built with culverts and the pipes are small. The culverts get clogged with water hyacinth, which impedes the water flow,” she said, explaining the reason behind the inundation.
Due to over-exploitation of ground water in Doddaballapur, Nelamangala, Magadi, Ramanagara and Kanakapura taluks, where the Arkavathi flows, there is no sub-surface flow. “So, when such flash flows occur, the river takes with it all the non-point pollutants, such as muck, garbage, construction debris etc,” she said.
Earlier, the Arkavathi would flow through the Byramangala dam, where around 70-80% of the waste would get arrested. “However, the dam is disconnected from the river. The river’s course has been diverted to protect the dam. This is an unscientific project,” she said and added that with this, all the pollutants were now flowing to Sangama and into the Cauvery.