BIOME ENVIRONMENTAL TRUST

# 264, 6th Block, 6th Main, BEL Layout, Vidyaranyapura, Bangalore 560097,

+ 91 80 2364 1690, water@biome-solutions.com, www.biome-trust.blogspot.com,

www.rainwaterclub.org

Background Krishna Lilac is a gated community located off Sarjapur Road.

The residents of this colony have no access to BWSSB water

supply or any form of a sewage disposal system. Hence, in order

to meet their water demands, tanker supply has been adopted.

There are 2 apartment buildings in Krishna Lilac with a total of

44 individual units. Krishna Lilac currently have 3 borewells in

the premises with only one of them yielding water. The colony is

also equipped with a main sump, having a capacity of 40,000

liters. The water supplied to Krishna Lilac is directed to this sump,

softened by chemicals and provided to the occupied households.

Approach Krishna Lilac have administered a 3 pronged approach in order to better their water management.

The processes include Water Sub-metering, Rainwater Harvesting and Wastewater Reclamation.

Water Sub-metering

The Water sub-metering adopted has been functional with positive

results. Such a system has ensured verifying and monitoring the

amount of tanker water supplied with a meter being installed at the

tanker unloading point. By metering the water usage of individual

households, the demand is tracked and informed while ensuring

billing transparency. This can be overall beneficial for the residents

as billing will be variable depending on the meter reading of the

individual household which is known. Such meters have been

installed on the terrace. The water consumed in common areas is also

monitored and equally expensed by the residents.

Rainwater Harvesting

The rainwater harvesting system installed covering 90 percent of

rooftop area, is in two phases, with respect to the two apartment

buildings within Krishna Lilac. In Phase 1, about 9.0 lakh liters of

rainwater is collected annually. 50 percent of this rainwater is

Case Study Name: Krishna Lilac Apartments Case Study #1

Location: Bellandur, Off Sarjapur Road

Implementation: Integrated Water Management System

BIOME ENVIRONMENTAL TRUST

# 264, 6th Block, 6th Main, BEL Layout, Vidyaranyapura, Bangalore 560097,

+ 91 80 2364 1690, water@biome-solutions.com, www.biome-trust.blogspot.com,

www.rainwaterclub.org

collected in a 5 x 5 x 10ft unit that is used to directly recharge a 650

feet deep bore well, located next to the building. Subsequently, the

other half of rainwater is filtered and directed to the existent main

sump. In the case of Phase 2, an annual rainwater harvesting

capacity of about 12.6 lakh liters can be achieved. The rainwater is

directed through a single downpipe into a 7 x 7 x 12ft recharge tank

located at the rear end gate. A percolation tank sized 5 x 7 x 10ft

has also been fitted to divert excess water when the recharge tank

is at capacity. The rainwater at the recharge tank is pumped to the

main sump via a filtration unit when a demand is present.

Wastewater Reclamation

The wastewater treatment system in place has a capacity of 50

KLD and in an average operates at 60 to 70 percent full. The

system follows a process of aeration, clarification followed by

filtration. The treated wastewater is then disinfected and used

for gardening and common toilets present in the colony. All

excess wastewater is diverted to the 2 percolation pits that have

been constructed. Each pit is sized at 30 ft. The remaining

sludge from the treatment system is dried and taken to a nearby

farm that is managed and operated by one of the residents.

Learnings With the implementation of this particular integrated water management system, the residents

managed to reduce their costs to a great extent. It was noted that, residents managed to reduce their

water demand by nearly 15 percent with the addition of sub-metered billing, or from 195 lpcd to

165 lpcd. In order to achieve the sub-metering, pipelines were retrofitted by the apartment plumber

within a period of 40 days, costing at Rs. 2800 per unit. With the inclusion of harvesting rainwater

for storage as well as usage, the dependency on water tankers reduced by an average of 1 tanker

load (6000 liters) per day. Subsequently, the reuse of the treated wastewater has also ensured the

reduction of the water demand. In fact, residents are in the process of looking to expand the

possible usage of the treated wastewater that can further reduce their demand by another 15

percent.