The sight of migratory birds like Marsh Harrier, Garganey, spot-billed ducks and many more at Alahalli lake is a bird watcher’s delight.

These winged guests have now made Alahalli lake their home. This, however, was not the scene three months back. Like most water bodies in the city, Alahalli lake was also on death row with sewage and weeds choking it. When public outcry to save this lake fell on deaf ears and their petitions ignored, residents took up the task on their own.

“I have finally realised that running from pillar to post to revive the lake is a futile exercise. It is apparent that this government is not serious about our lakes. My mantra now is ‘Muh Bandh, Kaam Chaalu’ (stop talking, start working),” said Anand Yadwad of Alahalli Lake and Neighbourhood Development Trust (ALNDT).

In association with Pavitra Foundation, Promac Industries and ward corporator K Somashekhar, ALNDT took up the revival work. Pavitra Foundation offered expertise and brought with it a Swedish “Truxor” machine to weed out water hyacinth.

Parvez Vohra of Pavitra Foundation said, “The task assigned to us was Herculean given the rocks and debris found inside the water body. This lake has been abused badly. Many a time, our machine suffered damage. Still, we could weed out only 75% of the lake. Thankfully, there is sufficient water and many birds have started coming here.”

The problem of sewage continues to pose a threat to the lake. Pavitra Foundation and ALNDT are setting up a sewage treatment plant of 5,000 litres to arrest the sludge and release treated water. The capacity is insufficient but it will help revive the lake to a great extent.

“So long as sewage flows into the lake, weeds will grow. The biggest threat from water hyacinth is it absorbs all the oxygen from water, endangering aquatic life,” said Vohra, who hails from Mumbai but has camped in the city for the last three months to clean up the lake.