Gardens take the eco route to greenery

The BMC’s order to stop supplying water to 1,000-odd parks and gardens in the city from March 2010 has put Mumbai’s green cover in danger of further deterioration. 

But Sagar Upvan, a garden maintained by the Mumbai Port Trust (MbPT) in South Mumbai, will remain pristine as ever. “We have a well-designed sewage treatment plant that meets our daily water requirement,” says Girish Shirsat, executive engineer, MbPT. The plant recycles 2.20 lakh litres of sewage water daily. 

The port trust had first asked the BMC to develop the 12-acre garden. “But they didn’t do anything,” says Mohan Chandran, MbPT corporate secretary. “So, in 1995, we spent Rs2.5 crore to develop the garden and also put up the treatment facility. The garden is now being managed by the All-India Association of Industries (AIAI).”

Shirsat says the sewage lines of the 125 flats in the MbPT Colony and over 100 servant quarters was diverted for the garden. Earlier, this waste water just flowed into the sea.
According to Rupa Naik, AIAI executive director, the association does not procure any water from the BMC. “Our annual expenditure on maintaining the garden is about Rs30 lakh,” she says.

According to Shirsat, though the initial expenditure was high, the treatment plant has proved cost-effective. “Currently, the cost comes to Rs250 for 10,000 litres. If we had to arrange for tankers, we would have had to spend Rs750 for 10,000 litres. Now we are saving Rs500.”

Taking a cue from Sagar Upvan, a garden in Khar is gearing up to face the impending water crisis. Starting February, 7,000 litres of waste water from the Sea Hill Cooperative Housing Society in Khar (West) will be treated and used to maintain the Union Park municipal eco-garden.

An advanced compact reed-bed system will be installed to treat the waste water. A reed bed provides natural filtration and does not require a complex set-up or highly skilled technicians.

The Union Park Residents’ Association (Upra), which has adopted the garden, has appointed water management expert Ajit Gokhale to set up the facility. “The drainage system will have to be modified so that the water can be transported to the garden,” says Gokhale. “A tank with a plastic liner will be set up at the bottom of the system to store the treated water. It will be filled with coarse media such as stone, gravel, brick, compost, and leaf litter. This will then be covered with soil.”

Gokhale says the bacteria, fungi, and earthworms in the soil and plants will help to purify the water.  The approximate cost of setting up this plant is Rs9 lakh.

Upra had conducted a geological survey and learnt that it couldn’t dig borewells in the garden. “There is a rock formation 4-5ft below the garden,” says Bharati Kakkad, Upra secretary. “While we will set up a percolation system so that the rainwater recharges the water bed, we won’t be able to tap it because of the rocky character of the ground.”