A different perspective to summer lakes

Over the last few days, the Bangalore edition of The Hindu newspaper has carried two articles on lakes, both involving our Puttenahalli Lake.

On 26th March, an article titled "Lakes turn into sewage pools" was published. In summary, it reports a complaint made by a citizen regarding the state of the lakes in Bangalore (including sewage and encroachment) despite more than Rs 200 crore of State money having being spent on them over the last six years, which has drawn the attention of the Upa Lokayukta. Many of us know that some of the rejuvenated lakes do not have caretakers and are hence falling into a state of disrepair. What bothered some of us was that the article was accompanied by an anonymous picture of a lake - our Puttenahalli Lake. (The article can be seen online here.) 

Given that the title of the article was incorrectly connected with Puttenahalli Lake, PNLIT trustees wrote to The Hindu informing it that the picture was misleading; that PNLIT is continuously monitoring the inflows and is prompt to take action to ensure that sewage does not enter the lake. 

Today, 30th March, the paper carries an article titled "Puttenahalli Lake is in better shape now". It reports PNLIT's efforts to keep sewage from entering the lake, along with a recent picture of the lake, which unfortunately, as with the first article, does not support the text. (The article can be seen online here.)

While not rushing to judge the intent of the second article, it brings our attention to two important aspects of lakes:

- challenges in lake management, including reckless acts such as burning, which we have posted about here

- life cycles of rain-fed lakes (most of Bangalore's lakes are rain-fed complex ecosystems). 

Life-cycles of rain-fed lakes

During a good monsoon, if the water from the surrounding areas is diverted to the lake, the level of water in the lake rises (June - December), as we have seen at Puttenahalli Lake this past year. With the retreat of the monsoon and the onset of summer, the water level starts dropping. In small lakes and ponds, while the deeper parts hold out, large portions dry out completely. 

Dr S. Subramanya from GKVK, while explaining the natural cycle of small lakes, had this to say about Puttenahalli Lake: 

The very fact that the water is still holding out at your lake is an indication that the ground water too is holding out. Let the water level hold on its own and let us allow the natural process to go on as it used to. Summer drying will breath a fresh life into the lake, once the pre-monsoon inflow starts. This is necessary to kill-off all the invasive plant species before the next monsoon arrives. This also gives us a chance to do the necessary repair-works in the lake-bed: get to work with spades to scrap-off those unwanted weeds, cleaning-up channels, drain pipes, etc.

While keeping this in mind, it must be said that for most people, the picture of a "lake" is one of perennial water. Along with BBMP/ BWSSB, PNLIT has been exploring the option of getting treated water (water that has been put through an STP) from nearby areas into the lake. This would ensure that a reasonable portion of the lake has water through the year. Jakkur Lake in north Bangalore is one of the successful treated-water lakes in Bangalore, and is now a potential model for Integrated Urban Water Management. (For more information, read here.) 

PNLIT is working to strike a balance. 

We hope that this information we have shared gives you a better perspective of lakes and gives you answers to the questions skeptics may pose when you talk of the "success" at Puttenahalli Lake. Dry lakes in summer should not be equated to "money down the drain".