Where do you begin to tell the story of a thousand deaths? Should you begin at the beginning and go on till you come to the end, and then stop? Perhaps. But the story of the lakes in Bengaluru would hardly lend itself to a linear narrative.

Earlier this month, the Ulsoor lake — famed for its gorgeous sunsets sliding behind a tiny island, boat rides set off against the champagne skies and a popular refuge from the sweltering summer days — saw its first fish-kill of the year. Hundreds of dead fish washed up on the shores, raising a mighty stench for passers-by and the dozens of plush lake-view apartments in the vicinity.

The news and pictures got a few column inches in the papers and a bit of airtime, but not for longer than a day. Eutrophication was old news even a decade ago.

The once quiet, sleepy town of Bengaluru had under its belt several sobriquets like the ‘garden city’ and the ‘city of lakes’ (the nearly 300 that came into being along with the city in the 16th century). The jacaranda and tabebuia trees that line the roads and parks in nearly every neighbourhood — however ill-maintained — still somewhat justify the first sobriquet. But the city grew into the gargantuan it is today by swallowing many of its lakes and spitting out a tragedy over several decades now.

Of course, not many people had stopped to notice.

According to a committee set up by the Karnataka legislature in 2014, an estimated 11,000 acres of lakebed has been encroached on, from 1,545 lakes, in both Bangalore Urban and Rural districts. One-third of the encroachments was by the Bangalore Development Authority and the rest by private land developers. Even until the 1960s, the city of lakes boasted 280 water bodies; today not more than 17 have survived.

A 2005 study by TV Ramachandra of the Centre for Ecological Sciences, Indian Institute of Science showed that waterbodies have shrunk from 3.4 per cent of the city area in 1973 to 1.47 per cent in 2005; the built-up area grew from 27.3 per cent to 45.19 per cent in the same period.

The fallout: flooding at the first hint of rain, changes in micro climates and drastic changes in the migratory patterns of birds. Not to mention the cultural changes to the face of the city, the death of snakes, frogs and other fauna in the vicinity, and the redundancy of a whole way of life — of fishermen, farmers and other communities that lived by these lakes and helped keep them healthy and alive.

While environmentalists and residents have been crying hoarse over the encroachment and filth endangering the lakes since the 1970s, it was the almost surreal foaming of Bellandur lake — the largest lake in Bengaluru — last year that caught national attention.

Reports of foam formation from the detergents and other chemicals draining into the lake began appearing in the 1980s.

But one day last year, the foam, already blowing on to windshields of cars and into the eyes of helmet-clad motorbike riders, caught fire. Cooking oil from the thousands of household drains that empty into the lake, is said to have reacted with detergents and other toxic chemicals to burst into flames.

Most of the city’s lakes were created more than 400 years ago by damming three natural valley systems — the Koramangala-Challaghatta, Hebbal and Vrishabhavathi.

The way it worked was that rainwater would fill the lakes and the excess flowed downstream into the next lake through stormwater drains, or raja-kaluves.

Today, untreated sewage flowing into the stormwater drains is, in turn, polluting the lakes all around and has long made the water undrinkable. The springs at the bottom of some of the lakes, which also once fed the lakes, are blocked by decades of piled-up silt. A lot of Bengaluru’s water supply today is dependent on river-based systems.

The history of attempts to save the lakes has been a chequered one. Along the way, the state government even tried to privatise the lakes and get large companies to adopt, clean and give the lakes — and the flowers, trees, birds and animals dependent on them — a fresh stab at life.

This step was met with a lot of resistance from the public and was eventually overturned. Cleanliness and awareness drives achieve what they can, but saving the lakes is an undertaking that demands a lot more, activists point out. Dealing yet another blow, the 2016 State Budget allocated a grossly insufficient ₹100 crore for lake development.

Citing the most recent fish-kill at Ulsoor lake, Ramachandra says the solution lies in treatment of sewage water. He explains that due to the higher temperatures in summer, there is an increase in biological activity and the level of nutrients in the lakes, leading to depletion of oxygen and the death of fishes in large numbers. Add to this the high ammonia levels in Ulsoor lake. However, rather than a simple sewage treatment plant, which not only cannot remove the nutrients but is also not cost-effective, what is needed is an integrated plan, like the one in force at Jakkur lake. “An algae pond and wetlands remove 90-95 per cent of the nutrients and the rest is removed by animals and plants along the way,” he says.

Leo F Saldanha, coordinator at the Environment Support Group (ESG), an organisation at the forefront of efforts to save the city’s lakes, points out that there are no easy answers.

He lays the bulk of the blame at the door of the big builders who have violated all guidelines when constructing lucrative apartments and villas offering lake views.

“An encroacher is effectively a polluter,” he says, pointing to the waste that enters the lakes from such dwellings. “The politics of the states is financed by real estate. Even when the encroachments are demolished, the government goes after the weak guys. Unless we go after encroachments, nothing effective can be done,” he says.

Pegging the health of lakes as a much more vital issue than road congestion, which gets inordinate attention and thus funds, Saldanha says investment in road development was aimed at the elite, much to the detriment of lakes. “Any farmer will tell you that water needs to flow on soil, not on concrete. Break the concrete lining of raja-kaluves and plant shrubs along the edges,” he adds.

Calling the state of lakes a “ticking bomb waiting to explode in our faces”, Saldanha despairs that the government has not displayed the nerve to act against encroachments. “Some predict that by 2025 we won’t have any water left in the city. We already don’t have any. What we have in Bengaluru is what we are stealing from Ramanagara, Channapatna, Mandya, and so on,” he points out.

Deepa Bhasthiis a writer and the editor of ‘The Forager’, an online journal of food politics