Built in 1894, the Hesaraghatta lake situated in Bengaluru, which has supplied water to several parts of Bengaluru for over a century, is filled to the brim after a long interval of 28 years. Torrential rainfall in the Arkavathi river catchment area and around Nandi Hills has caused an increase in the reservoir’s inflow.
According to a report in the Times of India, the lake is only a foot away from its full capacity and may overflow any minute. The lake is said to have come to full capacity for the first time since 1994.
The lake, now over 128 years old and spread over 450 hectares, was built across the Arkavathi river. It was a part of the ‘Chamarajendra Water Works’ project devised by MC Hutchins, the then chief engineer of Mysuru, to meet the growing demand for potable water in Bengaluru.
The lake began to lose its prominence and the inflow into the reservoir was affected by soil erosion, relentless sand and stone quarrying and degradation of the Arkavathi catchment area.
The reservoir has aqueducts built using bricks, lime and mortar that helped in getting water to places like Tarabanahalli where it would be purified and pumped to the city from the Soladevanahalli pumping station.
The lake was completely dry by 2010 and was even converted into grazing land by locals at one point.
Hesaraghatta’s spillway was designed by the chief engineer of Mysuru, Sir M Visvesvaraya. It is considered a unique spillway system in Karnataka with the 'volute siphon spillway' design comprising a vertical shaft in the form of inverted U-tubes.