Here are some nice water management systems kicking in in Bengaluru.These include rainwater harvesting,restoration of lakes, groundwater recharge,waste-water treatment and the creation of wetlands.

1. Water
Building resilience for Bengaluru

2. Cut to the present…
• How do we build resilience ?
• Distribute and de-risk dependencies..
• Decentralize
• Involve more solution providers
• Think multiple solutions…

3. Develop monitoring and prediction capacity
• The KSNDMC – www.ksndmc.org- for example has set up 196
weather monitoring stations in Bengaluru city alone . This data is
managed online
• All 5600 Gram Panchayaths have / will have weather stations
• A call centre provides 24/7 weather related information
• Mobile based information can also be subscribed to.

4. With water
• Integration and holistic approach best…

7. For water
• Think rainwater – can cause floods but can also help access more
water
• Think groundwater – map and inventory the aquifer and the wells
• Think surface water – use lakes and ponds as store and flood control
• Think waste-water – reuse , recycle and use ecosystem

8. Rainwater harvesting
• The city Bengaluru receives 970 mm on average annually
• This is spread over 8 months and 59 rainy days
• The equivalent rainwater endowment on the city is 3000 MLD as
against Cauvery water supply of 1400 MLD

9. MONTH DAYS QUANTITY (mm)
JAN 0.2 2.70
FEB 0.5 7.20
MAR 0.4 4.40
APR 3.0 46.30
MAY 7.0 119.60
JUN 6.4 80.80
JUL 8.3 110.20
AUG 10.0 137.00
SEP 9.3 194.80
OCT 9.0 180.40
NOV 4.0 64.50
DEC 1.7 22.10
TOTAL 59.8 970.00
Rainfall pattern in Bangalore Maximum rainfall intensity 90 mm/hour
30 years data

10. Hydro-flows from a small plot
Before building After building
• Surface runoff 15 % 90%
• Recharge 10 % 5%
• Evapo-transpiration 75 % 5%
• The aim of rainwater harvesting is bio-mimicry.
• To restore the local hydrology on a plot as before building

11. The new rainwater harvesting
bye-law for Bangalore City
• 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

12. EVERY ROOF IN A CITY CAN BE A CATCHMENT

13. Every well and bore-well a recharge structure

14. A rain barrel is the simplest way to harvest rainwater

15. Rainwater harvesting in an underground tank

16. A first rain separator and a simple sand filter

17. Harvested rainwater in underground sump tank

18. Training of plumbers crucial
• Understand rain (quantum/pattern/intensity)
• Cascade capture
• House/Apartment/Institution/Industry/Park
• Storm water harvesting in ‘tanks’/lakes
• Ground water recharge

19. Watersheds
• As a unit of planning for rainwater management

20. The ‘Tanks’ of Bengaluru
• 262 in 1962
• 81 now
• All manmade , none natural .
• All for irrigation purpose

21. Other boundaries we don’t think of :

22. Rehabilitaion of all water bodies crucial
Yelahanka Lake
Location: Near Yelahanka, Zone : Byatarayanapura Zone
42
Approximate Maintenance Cost per Month : Rs. 3.50 Lakhs

23. The new role of ‘tanks’
• Flood control
• Recreational
• Ecological
• Micro-environment modifier
• Recharge
• Cultural
• Percolation and recharger
• Treated waste-water

24. Groundwater
• Map all the wells
• Map the aquifer and the sub-aquifer
• Encourage recharge
• Understand draft
• Manage quality
• Create groundwater banks

25. Understanding and managing sub-aquifers

30. Rainbow Drive
• 37 acres on Sarjapur
Road
• 360 plots
• No BWSSB supply
• Only groundwater as
source.

31. What Rainbow Drive did
• Banned private bore-wells
• Shared community bore-wells 3 numbers
• Made recharge as a community , over 300 recharge wells
• Put in a place a tariff system based on true cost
• Treated wastewater from WWTP being used for non-potable use
• Now completely self sufficient for water

32. Storm-water harvesting

33. Storm-water designs

34. Green
storm-
water
drains

35. Leaky well

36. • 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

37. Don’t forget the maintenance

39. Tariff

42. Waste-water – the ecosystems approach
• It is compulsory for every apartment or layout of more tha 50 units to
have its own waste-water treatment plant AND to reuse the waste-
water under zero discharge norms
• The city has approximately 3600 small WWTP’s designed to treat over
400 million litres per day of waste-water
• In addition 25 WWTP’s are built/under construction to treat the city’s
1100 million litres of waste-water

43. Jakkur Lake – 18.9 sq km Catchment.
50 Ha water spread

46. Jakkur STP
 Design Capacity – 10 MLD
 Present Average Inflow – 8.5 MLD
 Wastewater generation – Yelahanka, Jakkur
 Process Adopted – UASB + EA (ASP)
 Wastewater discharged into – Wetlands at Jakkur
Lake
 STP’s discharging treated water quality
BOD5 < 20 mg/L
Iron (as Fe) 3 mg/L
Nitrate Nitrogen 30 mg/L
Phosphorus 5 mg/L

47. UASB Reactor

48. Treatment Plant and Jakkur Lake

49. Sludge generated – Approximately 8 tons a day

50. Sludge tested for heavy metals and N.P.K . Sold as
fertilizer

51. Treated Wastewater entering the WetLand System
of Jakkur Lake

54. Nature as treatment

55. Lake ecosystem – storm drain inlet with silt
trap

56. Approximately 200 kgs of fish harvested daily

59. Aquifer recharge around lake estimated at
7 million litres a day

62. Septage and sludge management

64. Vacum sucking a pit latrine

65. But how to compost and treat the sludge well ?

66. Compost after 3 months- sells for Rs 1500/-
to Rs 2000/- a tractor load

67. The fruits