A belief in tradition


Privatisation of water provokes protests
Gujarat: Enforcing water harvesting


Can micro-level initiatives be an answer
Disseminating novel wisdom
Water workshop in Gujurat


Groundwater dams


The second world water forum: confused event
Water and common sense




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Vol. 2                                    No.2                         April 2000

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Water Harvesting at CSE

In 1999, CSE installed a water harvesting system in its office premises at Tughlakabad Institutional Area, New Delhi. The system was designed in a way to ensure that drainage of rainwater from the premises is practically prevented, and maximum amount of rainwater is effectively harvested. For recharging the water, 13 soakaways have been constructed around the building. Each soakaway is 9 m deep and is filled with brickbats to act as a filter media. The mouth of each borewell is covered with an inverted earthen pot with a small hole to prevent the entry of debris which could clog the borewell. Further, the pot is surrounded by brickbats (broken brick pieces) to filter the runoff entering the well, and the entire assembly is covered with a jali – a perforated cover. Water that falls on the unpaved areas surrounding the building enters these soakaways and percolates into the ground.

An 45 m deep abandoned borewell in the premises has been converted into a recharge borewell by connecting the rooftop drains to it. Runoff from the terrace is passed through a grating to filter it before passing into the borewell. Water from the some portion of the terrace falls into an open pond in the front of the building, from where it overflows to an underground water tank of 8500 litres capacity.

FIGURE 1: A view of the entire system

FIGURE 1: A view of the entire system

Openings of the municipal stormwater drains within the area have been raised slightly above the ground level, so that rainwater does not drain away, except in case of a heavy downpour (see figure 3 ). To prevent water from flowing out of the campus through the gate, three soakaways have been constructed in a trough under the front gate.

FIGURE 2: Detail of recharge borewell FIGURE 3: Storm drains raised to prevent water from draining

FIGURE 2: Detail of recharge borewell

FIGURE 3: Storm drains raised to prevent water from draining

Because of the water harvesting system, only in case of an extraordinary downpour would water flow out of the CSE campus and it is ensured that all the rainwater falling over the building area is recharged or stored.

A rain gauge and water meters have been installed to monitor the rainfall and water-use in the building. On 13 March 2000, a short rainstorm of 7.5 mm occuring over 32 minutes was recorded, which effectively recharged about 4500 litres of water over the CSE area of 1000 sq m Although this quantity is not very large, it is interesting to note that this small shower contributed an amount of water equal to about 6 days of drinking water requirement of the entire 110-strong CSE staff at 10 litres per person per day.