Water sensitive urban design
Building resilience for our cities
S.Vishwanath
Biome Environmental trust
Zenrainman@gmail.com
…it is contextual
1.Opening of Indian economy 1991.—
GROWTH became the mantra…..
2. In Bengaluru establishment of
Electronic industries 1991—
becoming IT industries as now…
3.Year Population
1990 4,036,000
1995 4,745,000
2000 5,567,000
2010 7,469,000
2015 10,839,725
2016 11,556,907
Source :Ramachandra, T.V.; Bharath H. Aithal and Durgappa D. S. 2012. Insights to urban dynamics through landscape spatial
pattern analysis, Int. J Applied Earth Observation and Geoinformation, 18; 329-343, http://dx.doi.org/10.1016/j.jag.2012.03.005
Source : CH2M report for BWSSB
The invisibility of the resource
Photo : Raghu Rai
Cut to the present…
• How is inequity to be eliminated or reduced ?
• How do we build resilience ?
• Distribute and de-risk dependencies..
• Decentralize
• Involve more solution providers
• Think multiple solutions…
Key challenges
• Social
• Technical
• Institutional
• Financial
• Legal
• Environmental
• The knowledge services to be provided to the city – individuals,
communities and institutions .
Rainwater Harvesting
Local hydrologic cycle – seeking bio mimicry with rainwater harvesting
Hydro-flows
• Surface runoff 15 90
• Recharge 10 5
• Evapo-transpiration 75 5
• The aim of rainwater harvesting is bio-mimicry.
The new rainwater harvesting bye-law
• For every plot create recharge or storage
• @ 20 litres per square metre of roof area
• @ 10 litres per square metre of paved area
Minimum depth of recharge well 3 metres
How to harvest rainwater ?
• Understand rain (quantum/pattern/intensity)
• Cascade capture
• House/Apartment/Institution/Industry/Park
• Storm water harvesting in ‘tanks’/lakes
• Ground water recharge
EVERY ROOF CAN BE A CATCHMENT
Rain barrel : easiest way to begin rainwater harvesting
Rainwater harvesting in an industry
4 acres > objective 0% runoff
Rain Barrels harvesting rooftop rainwater
.
Quality check- using the H2S strip test for e.coli identification
Simple treatment using SODIS www.sodis.ch
Rainwater Harvesting Theme Park
Aerial View of Theme Park
Porous
Pathways
Green
storm-
water
drains
The ‘other’ benefits of rainwater harvesting
• Investment of Rs 750 crores approx. created
• Jobs for plumbers and well diggers
• Innovation in terms of nearly 40 rainwater filters developed
• Skill up-gradation of over 1000 plumbers
• Rainwater harvesting theme park created for water literacy
Storm-water harvesting
Leaky well
• Locate recharge well in the channel or off the channel
• Make arrangements to remove silt and leaves before water
enters recharge well
• Monitor the rate of recharge and decide on the number of
recharge wells necessary for the catchment
Don’t forget the maintenance
Storm-water designs
WSUD is about traditional livelihoods
Muniappa the well digger who has dug more than 3000 recharge wells
Ramakrishna and Shankar
…WSUD is also about construction and how
we build and what do we use or disuse
Is there a new possibility?
Can cities be not predatory?
Can cities be part of solution?
Solution is to look at the resources
to build them…
Solution is to look at how they will
live..
Solution is to empower people
coming to the city
Basements
Co-operative Collaborative Design Process
Units Mini Amit Vasanthi Uma Ghosh Sheeba
Plot Area sq.m. 368.0 218.5 220.8 147.2 346.7 220.8
Built Up Area sq.m. 290.9 272.0 389.6 175.5 151.4 225.0
Basement Area sq.m. 80.9 64.7 126.0 0.0 0.0 0.0
Soil Available cu.m. 149.3 149.3 263.8 0.0 0.0 0.0
Soil Required for
Earth blocks
cu.m. 55.2 55.6 38.8 43.9 27.1 47.0
Embodied Energy/
Earth Walls
KJ/m3 406.0 412.0 290.0 333.0 270.0 348.0
Embodied Energy/
Burnt Brick
KJ/m3 1027.0 1043.0 734.0 844.0 683.0 881.0
Embodied energy calculations from Auroville Earth Centre website
School- The Yellow Train
WSUD is about waste and what we do with it
Can buildings be
waste sinks?
Incorporating waste
Starting a new
project – use of
plastic as damp
proofing in the
bottom of the
foundation…..
"Old Men must die, or the world would grow mouldy , would only breed the
past again“
--Tennyson
Residence for Mr. Raghavan
Existin
g Plan
Segregation of Debris
Harvesting from the old
Processing the Debris
Residence for Mr. Raghavan
Alternates to conventional foundation
Alternates to conventional foundation – using debris
Residence for Mr. Raghavan
WSUD is a scale issue
• From an individual building
• To apartments
• To gated communities
• To micro watersheds
Rainbow Drive Layout, Bangalore
Classic Orchards Layout, Bangalore
Jakkur Lake, Bangalore
UASB Reactor
Treatment Plant and Jakkur Lake
Nature as treatment
Lake ecosystem
Jakkur Lake, Bangalore
WAY FORWARD….
• Replication has begun in a few
lakes including one with
Corporate Social Responsibility
and will need to reach all the
remaining lakes of the city.
• Will assist in the formulation of a
waste water policy in the
city/state.
WSUD is also about the city and its hinterland
Dakshina Pinakini river
• Flows capture the sewage from North and East of the city
• 700 to 900 million litres per day of untreated wastewater
• Being used extensively by farmers for cultivation including filling two
reservoirs in Tamil Nadu – Kelavarapalle and Kaveripattinam
Total irrigated area in Dakshina Pinakini
• Estimated to be around 5000 Hectares
Key Observations
• A vast hinterland of wastewater agriculture provides livelihoods and
employment in the city
• No formal institutional mechanism exists to monitor and manage this
• Farmers have made huge investments in pumping the wastewater
into their fields
• A risk management approach using the Sanitation Safety Plan
developed by WHO can be adopted in the short term
Septage and sludge management
Vacum sucking a pit latrine
But how to compost and treat the sludge well ?
Compost after 3 months- sells for Rs 1500/-
to Rs 2000/- a tractor load
The fruits
SMART ROOF as a generator of resources…………………
A SMART roof that grows rice
How about?
A SMART roof that grows vegetables
SAFE DRINKING WATER
GREY WATER TREATMENT SYSTEM..applied..transferred..
ENERGY
Turns Sewage to a Nutrient through Eco-san
ROOF
• 100 sq. mt. 100,000 litres of water
• 100 sq. mt 200 kgs of rice and vegetables
• 100 sq. mt. All the grey water –100 ltrs/day
• 100 sq.mt All the urine 1500 litres / year
• 100 sq. mt All the solid waste generated
• 100 sq mt 32 different species of birds
• 100 SQ mt Heat 100 litres daily
• Light 12 bulbs
• Cook for 4 people lunch and dinner
Water sensitive urban design, Bengaluru.

Water sensitive urban design, Bengaluru.