The cleaning process of the beautiful and popular Beira Lake spread over 65 hectares gets underway with the aim of making the lake attractive for locals and foreign tourists not just as a pleasant and tranquil view, but also as a quiet retreat from the hustle and bustle of urban life.
Created by the Portuguese rulers of Sri Lanka more than five centuries ago, to serve as a moat to defend their fort, the Beira Lake is today an “urban oasis”, a beautiful home for a variety of elegant water birds, the sight of which delights children as well as adults.
The placid waters of the lake attract spotted-billed pelicans, cormorants, herons, colorful storks and many other birds. However, seeing swarms of pelicans on the lake could be a matter of luck.
Seeing the tourism-generating potential of Beira Lake, the Sri Lankan authorities stepped up pollution control measures.
A few years ago, they worked with local enterprises to explore the use of Floating Treatment Wetlands (FTW), a technology that uses plants to clean severely polluted water bodies. This is done by the creation of “ecological floating islands” on the water body.
President Gotabaya Rajapaksa recently released a thousand ecological floating islands to Beira Lake initiating the purifying process of the lake.
Beira Lake has been polluted due to unauthorized urbanization and improper upgrading of sewerage infrastructure in the city of Colombo.
The “Ecological floating islands” method was implemented under the guidance of Chairman of the Land Development Corporation, Retired Major General M.R.W. de Soyza, the PMD reported.
Ecologist Ranoshi Siripala points out that the experiment conducted for water purification by planting plants such as Cannas, Savandara and Heliconia using PVC pipes, bamboo and foam mattresses as floating supports has yielded successful results.
Plants in floating wetlands absorb excess nutrients carried in the water. This reduces the amount of algae in the water and purifies the water, eliminates odors, and maintains an ecological balance by providing habitat for water-dependent organisms. Water surface beautification is another benefit, the statement said.
Land Development Corporation Chairman M.R.W. de Zoysa pointed out that the project is expected to play an indirect role in controlling the diseases caused by the mosquito menace. He said a number of other benefits such as increased density of fish can also be achieved at a very low cost from this project.
At the end of 2020, the local government began to implement the ecological FTW project in the southern part of Beira Lake. Almost overnight, many floating green islands appeared on the lake.
These floating beds of aquatic vegetation were anchored to the water. Some were on the shore, while others were at the center of the lake. Each of these floating islands was a beautiful, small garden.
Residents noticed that the aquatic plants on the ecological floating islands were mainly Iris, Canna and Vetiver grass.
Under a brilliant sun and a blue sky, the yellow, red and purple Canna flowers are an enchanting sight.
The floating islands gently drift with the wind of the Indian Ocean, and the water birds on the ecological floating island seem relaxed, enjoying the slow ride.
The pelicans are now more numerous than ever, with up to 100 gathering at regular intervals. In the morning, pairs of spotted-billed pelicans “paddle” in search of the first pickings of the day.
After feeding, the pelicans swim leisurely towards the floating islands or zip through the sky like a helicopter and land there.
An expert in the planning and design of constructed wetlands and the ecological restoration of polluted water environment in China, said that the floating island is actually a kind of artificial wetland floating on the surface of the water body with suitable wetland plants and aquatic vascular plants, which can purify the sewage entering the lake.
The wetland plants can also reduce the smell of sewage and provide a suitable habitat for aquatic animals and waterfowl.
The ecological floating island itself has the aesthetic and leisure tourism effect of a water garden.
As an expert who has done extensive research on Sri Lanka’s lakes, reservoirs and lagoons, said, “This is a cost-effective and relatively effective nature-based water pollution solution for Sri Lanka.