Aeration and Mixing Brought Hussain Sagar Lake's Ecosystem Back to Life
Toufiq Mirza Baig
Marketing Manager
Eurotek Environmental Pvt Ltd

Hussain Sagar Lake is a tourist landmark located between Hyderabad and Secunderabad, and spread across an area of 5.7 square kilometers. The water-body was built on a tributary of river Musi to meet the water and irrigation need of the city. During last few years the water became so polluted that it was declared unsafe for comsumption. The lake became shallow due to siltation and accumulation of plant debris. A grave concern was voiced by neighborhood about the deteriorating condition of the lake. With this context, Hyderabad Metropolitan Development Authority (HMDA) has decided to go for a lake rejuvenation work in year 2016. The author here endeavoured to pen down a concise account of the work done.

Overview: Hussain Sagar Lake in India faced an inflow of untreated waste and pollution thus causing a decrease in dissolved oxygen(DO ) level in water and foul odours in the nearby community. An even more critical threat was eutrophication, an excessive number of nutrients in the water-body choking out the natural aquatic life. Given the lake is stagnated , circulation and distribution of efficient aeration was needed to alleviate these issues.

Challenges: Hussain Sagar Lake is situated at a recreational area having regular footfall of many visitors. Due to the stagnancy of the lake owing to absence of outflow of water, finding out a solution for this issue was the need of the hour. The focus of the solution was to provide aeration and mixing in sections throughout the lake to support sludge digestion and mixing of the polluted water. Another deterrent was the heavy currents of lake water and high winds during rainy seasons. Therefore, the solution needed to be so designed that it can exhibit reliable performance in these varying conditions.

Solution: Aeration Industries International has provided successful water restoration to large-scale waterways from the Olympic Games to small golf-course ponds around the world. Eurotek Environmental Pvt Ltd has hands-on experience and an understanding about the needs of the lake cleanup and began the engineering process of developing a barge with aeration equipment set upon it. A pilot test was carried out and proven successful. The next step was to begin the restoration of the lake. However, the challenge was to make the barge robust, so that it can hold six 10hp Aire-O2 Tritons and two diesel generators. The barge was to clean one section of the lake at a time, while being maneuvered to the next location by a 75 hp OBM engine. The sludges within the lake as well as other pollution were broken down by the aeration and mixing, thus facilitating the revival of aquatic life.

Result: The waste and pollution had started to dissipate by the aeration and mixing generated by the barge unit in operation. The dissolved oxygen level in water, as well as the water colour started improving, odour and turbidity were decreased, and fish quantity increased. The regular operating schedule of the barge is 9 am to 5 pm every day, which has resulted continuous visible improvement.

Impact: The project has had a huge impact on the lake's ecosystem and brought the fish population back to life. The aesthetic value for the community has also been improved with the odour reduction and water -colour improvement. The health of surrounding plant-life has also been positively enhanced owing to this project.

The team of Eurotek and Aeration Industries found great value by working on this project with the improvement of community life and lake's ecosystem. They bagged the award from World Water Leadership Congress' Lake / River Aeration Systems in recognition of their work in this project.