The death of a river

If the Cauvery is the lifeline of the southern part of Karnataka and Krishna of north Karnataka, there is no doubt that the same status should be bestowed on the Arkavathy.

Though it is labeled as a minor river, the Arkavathy has a tremendous job to do and apart from feeding water to Bangaloreans, the river has several other tasks to perform. Over the years, the greed of mankind and lopsided development has led to a state where the river has almost dried up in several areas and many channels which once fed fairly large amounts of water and acted as tributaries have either dried up or have been encroached.

Rising near Nandi Hills, she joins the Cauvery after a 190 kilometer journey. She connects nearly 50 tanks and lakes and also fills up 375 tanks, most of which are used for irrigation. ‘

The Kumudavathi river, which is another small rivers at Shivaganga in Tumkur district and joins the Arkavathy at Tippegondanahalli (TG Halli), while the Suvarnamukhi and Vrishabhavathi merge at Doddamudavadi in Kanakapura taluk.

When Kempe Gowda founded Bangalore, he harnessed the potential of the Arkavathy and built the fist dam in this area at Hesarghatta. History tells us that Kempe Gowda and his successors built 75 tanks and lakes around Bangalore-Magadi-Savandurga-Yelahanka area and most of them continued to exists till the later part of the 19^th century.

The two major tanks-Hesarghatta and TG Halli met the water need sof Bangalore till the 1960s and the two rivers-Arvakathy and Kumudvati-continued to flow unrestricted. It was in the 1970s that the quest for more water to feed a growing populace began. Till then and this was till 1975, Bangalore got 24/7 water and all of it was from these two rivers.

Once the Cauvery entered the City’s pipelines, rationing of water commenced and today several parts of the city are reeling under water shortage and the Bangalore Water Supply and Sewerage Board (BWSSB) is struggling to meet the ever growing demand for water.

Today, the Cauvery meets 80 per cent of Bangalore’s water needs and the Arkavathy 20 per cent. Unfortunately, the Arkavathy is slowly dying and it is only recently that the State Government woke up to this threat and decided to launch a comprehensive programme to save the river.

The Government has entrusted the job of  rejunevating the Arkavathy to the Cauvery Neeravari Nigam Limited (CNNL). The Nigam has already conducted a preliminary study of the river and also called for tenders to take up work between Hesarghatta and TG Halli.

The Nigam has divided the catchment area of the river into three divisions-Hessaraghatta valley, Kumudvathi and Arkavathi.

The Arakavathy travels a 101 km route from Nandi Hills to TG Halli and on this stretch alone it is the main source of water for 167 small and medium tanks. There are more than a thousand such water bodied from TG Halli to Sangam in Kanakapura where the Arkavathy merged with Cauvery.

The Arkavathy flows through Chickaballapur, Bangalore Rural and Ramanagaram districts before joining TG Halli  dam via Manchinabelle dam. The Arkavathy was a source of drinking water for people of all these districts but today even animals dare not drink the water as it is heavily contaminated and polluted.

What makes the 4000 square kilometer Arkavathy basin all the more important is that the river flowed, ground water was easily available in and around Bangalore and all along its course just at a depth of one to three metres.  Studies have shown that there were at least 30000 wells and they provided more than 56,000 litres of drinking water.

Apart from man made reasons, the drying up of Arkavathy has a natural reason too. The six year drought in parts of Bangalore district and which affected the Arkavathy basin the most, between 1980 and 1987 led to a slow but sure choking of all water bodies.

Almost all the 30,000 wells went dry and the Government and municipalities then went in for deeper wells called tube wells and it was in this period that borewells began to dot the landscape. Slowly but surely, the ground water dropped.

Agriculture ceased in many areas and they were converted into sites for layouts factories. It was around this time that Hesarghatta too completely dried up and the TG Halli too began recording lesser water levels.

The dry lakes and water bodies became prime targets of encroachments. Even the forests were not spared and slowly the lopsided development took its toll. The Arkavathy began drying up and its course too shrunk.

Apart from the Hesarghatta tank, another huge tank-the Nagarkere of Doddaballapur-which was fed by the Arkavathy too dried up. The dry tank bed became an open invitation for more than one hundred industries to set up shop. Another hundred industries soon followed and today there are more than 220 industries discharging industrial waste and effluents into the Arkavathy.

The polluted water of the Arkavathy subsequently flows to Doddatumakur and Chikkatumakur before reaching the Madavara tank from where it finally reaches TG Halli.

The fully polluted Arkavathy then further flows as a five-kilometre stretch into Ramanagara. Smaller rivers of  Vrishabhavati and Suvarnamukhi join the Arkavathy at Doddamuduvadi and all the three merge into the Cauvery at the Sangama in Kanakapura. This is the same Cauvery water which is supplied to Bangalore in five stages.
This is how Cauvery came to Bangalore and today more than 80 per cent of the needs are met by the Cauvery