Water is essential for life but cities face challenges in securing adequate supplies. Bangalore gets its water from the Cauvery River 95 km away and 500 meters below the city. Most households get water through taps connected to overhead tanks that are pumped full from underground sumps, but many lack piped connections and rely on tankers or borewells. After use, water is meant to go through sewer systems to treatment plants before reaching lakes, but mixed sewage and stormwater often bypass treatment. Individuals and cities can harvest rainwater and recharge groundwater to help address flooding and scarcity issues.

1. Water
Water and a City
Rebuilding an Urban Water Culture
Biome Environmental Trust
Shubha Ramachandran

5. How much water do I use ?
Use Litres/person
Drinking 3
Cooking 4
Bathing 20
Flushing 40
Washing-clothes 25
Washing Utensils 20
Gardening 23
Total 135
Real Consumption range :
from 50 to 300 liters per person per
day
National Town planning Norms :
Urban : 135 Lpcd
Rural (Karnataka) : 55 Lpcd

6. WATER AVAILABILITY
AND
WHERE DOES MY WATER COME FROM ?

7. Cities search for water
•Chennai: 235 km
•Bangalore: 95 km
•Delhi: from Tehri dam (450
km).
Chennai
Veeranam lake
Map of Tamil Nadu

8. Manjira dam
Hyderabad
Nagurjuna
105 km
100 km
Himayat Sagar
Osman Sagar

9. Vaitarna cum Tansa
90 km
105 km
Mumbai
Bhatsa

10. Bangalore need
Bangalore
Bangalore gets its water from the Cauvery 95 kms and 500 meters below the city

11. My water comes from a tap !!

12. My tap gets its water
from an overhead
tank......
.....to which water is
PUMPED from my sump
tank........
And
My sump
tank
Gets water
from ??

13. But Many people don’t
Have “taps” at home !!!!
(Many places
don’t have
City/municipal connections
and many cant afford it)
Where do they get their
Water from ???

14. .... The unlucky many.....

15. …..And the lucky few…..
Tankers or borewells borewells !!

17. .... Some (i think) clever lot.....

18. WHAT HAPPENS AFTER THE WATER HAS
BEEN USED

19. What happens to all the water I have already used ??????
Use Litres/person
Drinking 3
Cooking 4
Bathing 20
Flushing 40
Washing-clothes 25
Washing Utensils 20
Gardening 23
Total 135
I use
clean water
And i throw out
Dirty water
What happens to
The rainwater that
falls on
My house ?

20. The Sewerage treatment plant
Primary, Secondary and Tertiary treatment

21. …sewer and storm water drain
networks ….
Sewage
treatment
plant
Lakes
And tanks

22. …but then many times storm water and
sewage water gets mixed….
….. And lands up in lakes untreated…..

23. Photo : Norma Angelica Hernandez Bernal
Ultimate source of all water :
RAIN

24. Local hydrologic cycle

25. Twin problems
Urban FloodingWater Scarcity

26. PARADOX ?

27. Rainwater harvesting
components:
1) Catchment
2) Conveyance
3) Filtration
4) Storage
5) Recharge
<<< The saree is the
Catchment, conveyance
And filter !!!!!!
The collection and storage of rain for future productive use

28. 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
30 years data

29. How much water can I harvest

30. How much water do I use ?
Use Litres/person
Drinking 3
Cooking 4
Bathing 20
Flushing 40
Washing-clothes 25
Washing Utensils 20
Gardening 23
Total 135
Real Consumption range :
from 50 to 300 liters per person per
day
National Town planning Norms :
Urban : 135 Lpcd
Rural (Karnataka) : 55 Lpcd

31. How much water can I harvest
Plot Size Area(sqm) Avg 30mm
rain runoff
(KL)
Annual
970mm rain
runoff (KL)
No of days of
use
30ft x 40ft 110 3 96 142
60ft x 40ft 220 6 192 285
50ft x 80ft 367 10 321 475

Assumed 5 member families with a daily per capita consumption of 135 litres

Assumed only 90% runoff from rooftops

32. ….So how clean is Rainwater ?....
Rainwater in a Glass
Cauvery water in a Glass
-
Guess
Which is which ?
A Bucket of Rainwater in
Kurubarakunte village, Bangalore

33. A clean roof means clean water

35. Join all the pipes……

36. Bring it to a Storage

37. Clean Rainwater :FRS &
Filtration

38. First rain separation – let the rain clean the roof

39. Filter

40. Commercial Filters

42. Rain barrel : easiest way to begin rainwater harvesting

43. Storage

46. Groundwater recharge : Wells &
Borewells

47. …a source and a sink
GROUNDWATER
Sink
Source

62. Digging an
open well
step by step
First the soil is
excavated to the
desired depth.
You may
encounter rock
or water
inflow/seepage.
The hole is
normally 6”-8”
wider than the
external dia of
the concrete
rings.
These wells can
cost anywhere
between 20k and
100k INR.

63. The soil is
excavated to
the required
depth
Concrete
rings are
lowered in
one by one
into the well
Aggregate or
jelly stones
line the gaps
between the
rings
This
reinforces
the well
structure

71. MILLION WELLS !!

72. GROUND Water
● What DOES an individual do ?
● What DOES a City do ?
● What CAN an individual do ?
● What CAN a City do ?

73. PRINCIPLES ?

82. Floating wetland pic
82

87. Waste Water
● What DOES an individual do ?
● What DOES a City do ?
● What CAN an individual do ?
● What CAN a City do ?

88. PRINCIPLES ??

89. THANK YOU !!