Imagine Hosur getting 14 cm of rain in a 24 hour period. An unprecedented downpour that leads to flash floods. The rushing water from the flash floods sweep people away, leading to death and severe injuries. Animals and vehicles are either washed away or submerged in the water. Trees start to fall down and the power supply of the whole region gets disconnected. 

The above scenario was not merely fiction. A devastating flash flood did indeed occur in Hosur on a night of heavy rainfall in July 2016. The consequences were catastrophic, with loss of life and widespread destruction. 

Hosur is located on the banks of the Ponnaiyar River in the Krishnagiri district of Tamil Nadu. The industrial city was once famous for its horticulture and floriculture, especially the cultivation of roses. With the growth of medium and large-scale industrial units, Hosur has been on the spurt of industrial development in recent years. 

As a thriving industrial hub, Hosur has a mix of small and large-scale enterprises. The city excels in manufacturing automobile bodies and spare parts, as well as precision components for the aerospace industry. This has led to an increase in concretization that does not allow water to penetrate into the soil.

Hosur’s industries rely solely on local water sources, either from surface water or groundwater resources. This has led to groundwater depletion, with extraction rates exceeding replenishment rates. Widespread concretization also meant that water cannot infiltrate into the soil and recharge aquifers even during heavy rainfall.

To enhance groundwater recharge and prevent flooding, E.F.I is introducing a new initiative- the Hosur Sponge Park. Excited to know what it is? Read on.

Presenting the 4 Ps of Hosur’s Sponge Park: people-pond-park-path.

Hosur is undergoing a remarkable transformation, thanks to a collaborative effort between E.F.I and the Hosur Corporation. Once neglected and encroached upon OSR (Open Space Reservation) land is being rejuvenated into a vibrant sponge park. This innovative project aims to create recreational spaces with green cover and water retention facilities.

The Hosur Sponge Park is located adjacent to the 100 ft road and runs for a distance of around 1.8 kms. An area of 0.9 acres out of this long stretch is currently being worked on with deweeding completed throughout the area. The sponge park consists of various zones that contain a plantation area, footpath, drain and sponge pond with recharge wells.

• Drain

A 1.5-meter wide drainage channel will be constructed alongside the plantation area. This channel runs parallel to the length of the plantation and effectively collects excess water from the area. The collected water is then directed towards a sponge pond through a specifically designed inlet pipe connected to the drain. 

Hosur receives the minimum rainfall of 767.7 mm out of all the other parts of Krishnagiri district. Thus it is essential to collect the rainwater and store it for the future.  Since the 100 ft road is a sloped area, rainwater does not stagnate in the region, making it difficult to recharge groundwater. Thus, the drain is essential to prevent surface runoff and enhance the water retention capacity of the pond.

• Plantation Area

A traditional type of plantation with native trees such as neem and bamboo has been proposed as they offer a variety of ecological benefits. 

1. Native trees possess deep root systems adapted to the local soil conditions. These roots penetrate deeper into the ground, facilitating greater water infiltration and recharge of groundwater. 
2. Native trees help in moderating local temperatures, thereby reducing the urban heat island effect in Hosur.
3. Native trees provide food and shelter for local wildlife and contribute to biodiversity conservation.

• Recreation

A well-maintained footpath provides access to different parts of the park and offers a recreational space. A footpath of 1.5 meters will be constructed on both sides of the sponge pond to provide a scenic route for the community. The footpath encourages movement around the park and improves the physical well-being of the community. Relaxation spots with benches will be incorporated throughout the park. 

• Sponge Pond with Recharge Wells

The sponge pond is a 8.67 meter long, rectangular-shaped water body designed to store water and recharge aquifers. It’s equipped with rectangular recharge wells of 6 ft depth that facilitate the percolation of water into the groundwater table. A total of 5 sponge ponds will be constructed in the Hosur Sponge Park. These ponds will act as a reservoir during dry periods and create a cooler microclimate in the park. They also aid in creating a rich ecosystem by attracting a variety of wildlife, including birds, amphibians, insects, and aquatic plants. 

Take a look at the works currently underway in the Hosur Sponge Park:

Sponge Park collecting rainwater and recharging it into the ground.

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