The ecological restoration of Datha and Basthi Lakes

Sometimes, you don’t realize there was once a lake where currently an empty, open ground lies. Slowly, it turns into a dump yard or an abandoned land which becomes a playground for the children staying nearby.
Sometime there is water, but you brush it off as a puddle that was formed due to the previous day’s rains.
It may even look lush green due to the grass and weeds.

If you have been living in the vicinity of such a piece of land for years, you might notice that it has been shrinking in size. These are signs of a lake that was once thriving, sheltering birds, collecting rainwater, providing shade and local climate control throughout the year.

E.F.I is collaborating with Hosur Municipal Corporation to ecologically restore two such lakes in Hosur: Datha Eri and Basthi Lake. We have surveyed the lakes to understand the need for restoration and the subsequent steps to be followed. Restoration is yet to commence for Basthi Lake, Datha lake is half-way on the path of being fully restored.

Hosur lies close to the border Tamil Nadu shares with Karnataka. Hosur is a rapidly urbanizing, industrial city where many manufacturing industries have been set up. Due to its proximity to Bengaluru, Hosur is a favorable location for investors, with the benefits of urbanization – better roads, more connectivity to nearby cities and quality infrastructure. It is a hub for small-scale enterprises to network and grow their industries.

This has put a strain on the natural resources of Hosur. The urban and economic development has also led to a growth in population. Thus, Hosur has started seeing a decline in its groundwater levels.

Hosur is at an average elevation of 880m. The city’s climate is tropical, with healthy monsoon showers in the months of August, September and October, and occasional thunderstorms in the summers. The scenery is beautiful – it is interspersed with lakes, surrounded by hills, forests and waterfalls. Krishnagiri’s hills and Sanamavu forest to Hosur’s east, and multiple reserve forests to its South, provides the city with rich biodiversity and ecosystem services.

Given that the groundwater levels in Hosur have been depleting since the past decade, it is time to restore existing lakes and ponds that could add to the city’s rainwater harvesting potential and restore its natural groundwater recharge system.

Conserving Hosur’s natural environment could set an example for other developing cities to understand how an urban, built environment can coexist with the natural ecosystem.

Restoration activities planned for these two lakes include:
1. Removal of garbage from the lake bed and its periphery.
2. Removing excess silt deposit and soil from the lake bed (de-silting) to increase the area and water-holding capacity of the lake.
3. Constructing bunds to give it a firm structure.
4. Recharge pits – These are made in the lake bed, with higher than average depth to increase the percolation of lake water into the ground water table.
5. Nesting islands to attract birds and increase green cover.

The key restoration process that will be followed for Datha and Basthi lake is the formation of recharge pits. This will help Hosur replenish its depleting groundwater levels.

E.F.I always aims to involve the local community in restoration projects. Once the lakes are restored, a plantation drive will be conducted with local volunteers, to plant native saplings around the lake boundaries. While trees purify the air and regulate humidity in the micro-ecosystem of Hosur, they also create a greener habitat for birds and insects around the lake.

The sounds and sights of a water body are much needed for our peace of mind, and also create a sense of responsibility and belonging with the nature among the community.

The images below show the work-in-progress for Datha Lake.

Keep visiting this space for updates regarding Hosur’s lakes.

Do check out EFI’s other restoration efforts in Hosur, for Alasanatham lake by clicking on the following link: https://youtu.be/_TXSkW7Qvu0.

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