Expert reveals how and why Neerasagar dries up frequently

DHARWAD: Neerasagar Lake near Dhumvad on Kalghatagi Road, about 15km from Dharwad, was the main source of drinking water to Dharwad till Malaprabha was added in the late 1970s. It continued to be a source of water to parts of Hubballi till recently.
The lake has been drying up frequently and is almost completely dry causing a shortage of drinking water in parts of Hubballi.The district administration had planned to develop the lake into a picnic spot by providing necessary facilities and increasing greenery around the lake. However the plan remains shelved.
Professor Vinayakrao K Deshpande, who had presented a paper at International symposium on Tropical Ecology at Varanasi in 1988, traces the reasons for the lake going dry frequently. He says it is the impact of urban development on fresh water resources.
Professor Deshpande said three main streams, Bedti Halla, Attikolla Halla and Shalmala Halla feed Neerasagar reservoir. “A Bombay State gazetteer compiled by Venkat Rango Katti in 1884 clearly shows a map of these three streams forming the Shalmala River, which is now said to flow underground up to Mishrikoti, where Karkihalla from Hubballi joins it,” he says.
“Extensive deforestation on the hill ranges in this area resulted in soil erosion over hundreds of years and silted the stream beds, thus preventing smooth flow of rain water. That is the reason for Shalmala going underground,” he adds.
“Irrigation tanks have been built along the course of these streams and the stream beds are converted into paddy lands downstream. Excess water is let out into a narrow channel, further joining other tanks like Mangundi. Jammihal and Dhumwad tanks and paddy lands submerged in Neersagar, built in 1957,” he says.
The professor recalled that water from the lake was supplied to Dharwad only for two three hours every day in the morning for the next 25 years.
“Now rainwater is trapped by small bunds to feed the brick kilns along Attikolla Halla before it joins Managundi tank. Abandoned stone quarries around Mugad and Mansur trap rainwater flowing towards Bedti Halla which originates from Mugad tank. After the construction of NH4 bypass in 1992, rain water is not flowing beyond Mansur. Urban development, extensions and layouts on the hills are also blocking storm water drainage towards Neerasagar,” he says.
Now, only Bedti Halla is feeding water into Neerasagar when there is sufficient rainfall in that area,” Prof Deshpande observes.
“If at all Neerasagar is to be revived, satellite images are required to trace the underground flow of Shalmala,” he adds.
Developed in two phases
Neerasagar lake was developed as a drinking water source for Dharwad in two phases - first in 1950 at a cost of Rs 1.7 crore and then in 1969 at a cost of Rs 48.17 lakh. The lake has a catchment area of 181.08 square km and can hold 28.9 million cubic meters of water. The water level when the lake is full is 590.85 ft. The lake was full to the brim in 1938. The maximum height of the tank bund is 24.6 metres.