Soon you may be able to spot more fish in the lake in the Lalbagh Botanical Garden as it’s getting ready for a makeover, one that will improve the quality of water. Eight low-level aerators and one high-level jet have been placed in the lake to supplement oxygen in the pond water.
Explaining the benefits, M. Jagadish, joint director, Department of Horticulture and Parks, Lalbagh said that it would lead to the movement of oxygenated water in the lake, which would enhance the aerobic conditions to support aquatic life. It will also improve the quality of water in the lake. “The plants in the lake will grow well as the dissolved oxygen content in water would be increased,” he said. The lake water is currently green due to the algae, and with these additions, it will become ‘crystal clear’.
The lake is spread over 30 acres in the 240-acre park. While the aerator will operate over a three-metre radius, the high jet will spring water up to 60 feet.
Water quality
The State-run research organisation EMPRI had noted that the absence of aerators had left even rejuvenated lakes with low dissolved oxygen, resulting in fish kills.
“But during rejuvenation of water bodies, the plan to maintain the DO concentration has not been considered...Therefore the aeration should also be considered as the core rejuvenation activities, and action shall be taken to install the aerators and fountains,” says the report on lakes in the city.
According to Karnataka State Pollution Control Board, the water quality in Lalbagh routinely touched ‘D’class (for propagation of fisheries only), which is the second lowest grade possible.
Benefits of aerators
Mr. Jagadish said that each aerator would be placed at a distance of 15 metres from each other. These will be switched on for a minimum of six hours a day from Monday. He said the timings would be decided shortly. “Having these aerators would also help reduce the temperature around the lake,” he said.
The Horticulture Department has spent ₹30 lakh for this purpose and decided to take up this initiative after they took the opinion of various experts, including environmentalist A.N. Yellappa Reddy.
Mr. Reddy said that if the oxygen levels would increase in the water, the bacteria would eat the algae which was covering the surface and preventing the penetration of sunlight.
M.R. Doreswamy, advisory committee member of Lalbagh and Cubbon Park, said that it was a welcome move as it would help improve the quality of water in the lake and also the aesthetics in Lalbagh.
