Percolation Pits Construction

Percolation pits plays a pivotal role in increasing the ground water table in an area. Every building structure is mandated to have percolation pits of recommended dimension by the civic authorities.

The percolation pits are shallow structures that help the rainwater to permeate through soil strata. Along with percolation trenches they play an important role in ground water recharging. Though they are not as efficient as structures like bore wells, open wells where rainwater can be directly charged to the aquifer, they are still a better choice when compared to wasting the rainwater and letting them into the sewage drain system.

Water Inlet to Percolation Pit

Generally, we recommend providing water inlet to the percolation pits from the excess flow after exhausting the storage structure with harvested rainwater. So a valve fitted is turned on to percolation pits once the storage of rainwater is complete.

The Pit

The rainwater harvested needs to be filtered before storing. Rainy filters are water filters specifically designed to filter rainwater from our terraces. The heavy duty filter made of HDPE works on the principle of centrifugal force and hence no power is required to operate them.

RCC Rings

After the rainwater is filtered by Rainy Filters they are connected to pipes once again which in turn drains the filtered clean rainwater to storage like tanks or underground sumps. The storage is fitted with outlet pipes which take the excess rainwater to percolation pits.

Fillers for Percolation Pit

A percolation pit specified as per the norms of the civic authority receives the excess runoff rainwater after filling the storage. The pit filled with sand, gravel and other materials is a shallow structure that helps in percolating the rainwater thereby increasing the groundwater.

Percolation Pits

How we lay them to recharge your groundwater

Digging of Pit

A pit of 1-2m wide and 3m deep is first dug. This dimension is the minimum norm as laid by the civic authorities. The dimension can vary depending on the plot size. A large apartment with multiple household can either have a bigger pit or can have multiple pits based on the land availability pattern.

Laying of RCC Rings

Once the pit is dug, it is laid with RCC rings or concrete rings. These rings provide support and structural stability to the pit. They eliminate the need to construct a concrete pit. The RCC rings when placed one above the other can help in water seepage horizontally also through the gaps present between them.

Filling of the Pit

The bottom 50% of the pit is now filled with 40mm gravel. The middle 25% of the pit is filled with 20mm gravel and the upper 15% will be filled with coarse sand. The remaining 10% is left open. A one layer brick wall surrounding the pit is laid and the pipe carrying the runoff rainwater is let inside this pit.

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