Lake in need of a life jacket

The only structure one remembers was a window where freshly collected vegetables and

fruits from farms were sold. One could gorge on the exotic litchi fruit available in plenty here. In the course of time, however, the beauty of this place began to fade, what with all the urbanisation. Owing to the reduced inflow of water into its basin year after year, the lake is dying a slow death. 

Decades ago, the river Arkavathi originating somewhere near the Nandi Hills coursed through this region on her way towards Kanakapura to merge with the Cauvery. The idea of building a reservoir across the river so that the water supply needs of Bangalore could be met was thought of by the then Dewan Sir K Sheshadri Iyer and the Chief Engineer of Mysore M C Hutchins. A 5544 ft.

long earthen bund reinforced with stonework was built in 1894. A volute siphon ensured the passage of excess water when levels were high. The Hesaraghatta lake was formed because of the uninhibited inflow of water from streams and rivulets in the higher reaches of the catchment area. It was not only a project for water supply but turned out to be a beautiful picnic spot.

Thriving biodiversity

Biodiversity thrived with a myriad species of trees and shrubs and a healthy population of lesser wildlife like snakes, frogs, butterflies and insects. The avifauna too varied with kingfishers, egrets, cormorants and robins apart from raptors like Brahminy kites, blackshouldered kites and harriers. The lake was a haven for water sports too. The area around became a hub of activities such as farming and animal husbandry.

The Indian Institute of Horticultural Research, Indo-Danish breeding farm, pisciculture, rabbit rearing etc all sprang up.  Though the initial objective in building the reservoir was to store water for a few years, the project sustained much longer.

Channelling the water through a pipe to the nearby Soladevanahalli village and pumping it to the drinking water network of the metropolis was taken up for many years. However, ‘development’ activities around the lake and in catchment areas had a telling effect on the life of the lake.

While mindless granite quarrying eroded the catchment areas and also filled the streams with debris, the sand mining around the water body only added to the problem.

Accumulation of silt suffocated the inlets to the reservoir thereby gradually reducing the water content. Another phenomenon that had a direct bearing on the water inflow was the unabated construction of numerous check dams higher up and countless borewells dug by those farming around the lake.

The water table too started to sink. The lake began to shrink and by 1925, it almost dried up and the pumping station ceased to function. That was when another dam was built downstream at Tippagondanahalli near Magadi from where the supply of water to the city continued. The last time Hesaraghatta reservoir touched the brim was in 1994, reports say.

Revival of the water body

The deteriorating lake urgently needs to be revived so that water requirement of local people is addressed besides making it a picnic spot. There have been concerted efforts by NGOs like Arkavathi Kere Ulisi Andolana Samithi (AKASH), a movement to save the lake, and Friends of Hesaraghatta to rejuvenate the reservoir by deepening the inflow path.

But the steps to be taken on priority are desilting the lake, preventing erosion of catchment areas, total ban of sand mining and monitoring  the check dams and borewells, all of which have to be initiated by the authorities concerned.