By Samrat Basak, WRI India

1. A product of WRI Ross Center for Sustainable Cities
ARE WE NEARING DAY ZERO?

2. WHY THIS DEBATE

3. February 2018 July 2018
IN THE NEWS

4. KEY WATER POSITIVES
~11 million people are getting ‘improved’ supply of water
No major outbreak of water borne disease reported so far
Basic water supply (for human health and livelihood) was available even during
climatic stress period
Water supply network coverage expanding as the city grows
Reported budgetary provision for infrastructure upgradation to meet future water demand
*As per UN definition improved water supply is a mix of piped and non-piped supply (boreholes, tubewells, protected wells and springs,
rainwater, packaged water (bottled and sachets) and delivered water (tanker trucks and small carts))

5. Natural
Resources
Watershed
Surface water
Groundwater
Stormwater
Water quality
City
Open space
Green and
blue cover
Supply
infrastructure
Access
Other
Climate
change
Strategic
priorities
Political
Priorities
Citizen
behavior
Economic
condition
KEY WATER STRESSES

6. FUNCTIONING
19 TMC (APPROVED) + 10 TMC (PROPOSED)
HISTORY OF BENGALURU’S WATER SUPPLY
1500s to 1896 1896 to 1974 1974 to present
Source: Anon. Historical Map of Bengaluru, India,
circa 1924. Wikimedia Commons
Source: Shyamal L. Hesaraghatta Lake. 2007.
Wikimedia Commons
Source: BWSSB. EMPRI. Water Safety Plan for
Bengaluru. 2014
KEMPEGOWDA AND COLONIAL REIGN
Interconnected cascading tank system
with 100 + tanks for rainwater storage
and water supply for Bengaluru
ARKAVATHI RIVER
1896 – Hesaraghata Lake – 1st large
reservoir for filtered water supply
1933 – 2nd reservoir at TG Halli due to
drying up of Hesaraghatta Lake
CAUVERY RIVER
1974 to present – BWSSB expands
water supply from Cauvery River to
meet increasing demand of Bengaluru
DEPLETED

7. SURFACE WATER SOURCES FOR BENGALURU
Map generated by WRI India for study purpose only
Intake point on Cauvery – 1,350 MLD
Intake point at TG Halli
Reservoir
Historical Intake Point at
Hesaraghatta Lake – Now Dried-up

8. SOURCING WATER FROM CAUVERY
Source: Google Earth Pro | http://www.indiaspend.com/cover-story/bengaluru-wastes-nearly-50-water-
supply-from-cauvery-53879
BWSSB spends nearly
60% of its budget pumping water to Bengaluru.
Cauvery River
Bengaluru City
Shivasamudra
Elevation at Bengaluru City
Elevation at Shivasamudra

9. CHANGE IN CAUVERY WATERSHED CONDITION
Data source: MODIS (USGS/ NASA); BBMP | NDVI index used to estimate vegetation changes | *Tree cover loss estimated using Global Forest Watch-
Water (http://water.globalforestwatch.org ) | Map generated by WRI India for study purpose only
The watershed upstream of Bengaluru’s intake
point has suffered ~5000 Ha of tree cover loss
from 2001 to 2014*
Loss in tree cover impacts water availability
and water quality at a catchment level.

10. CHANGE IN CAUVERY WATERSHED CONDITION
Data source: Global Forest Watch-Water (http://water.globalforestwatch.org )
Tree cover lost in watershed approximately the area
of 1,500 Chinnaswamy Stadiums

11. MULTIPLE DEFICIENT RAINFALL EVENTS IMPACT
SURFACE WATER AVAILABILITY
Normal rainfall
Deficient rainfall
Mean rainfall
880 mm
Scanty rainfall
1871
1875
1879
1883
1887
1891
1895
1899
1903
1907
1911
1915
1919
1923
1927
1931
1935
1939
1943
1947
1951
1955
1959
1963
1967
1971
1975
1979
1983
1987
1991
1995
1999
2003
2007
2011
2015
0
200
400
600
800
1000
1200
0
200
400
600
800
1000
1200
Average Annual Rainfall Mean Deficient (-20% to -60%) Scanty (-60% to -90%)

12. 0
10
20
30
40
50
60
70
-50
-30
-10
10
30
50
Dead Storage KRS Dead Storage Kabini KRS Capacity Kabini Capacity
RESERVOIRS HYDROGRAPH AND SIGNIFICANT STRESS PERIODS
Data on reservoir levels is sourced from Karnataka State Natural Disaster Monitoring Centre (KSNDMC) | Dead storage details of reservoirs
sourced from Karnataka Water Resources Department | All volumes reported in thousand million cubic feet (TMC)
Datagap(Jan-May2012)
Dead Storage K.R.S. Reservoir: 4.401 TMC
Dead Storage Kabini Reservoir: 3.52 TMC
8.9
7.8
Capacity in reservoirs at MDDL (an indication
of CRITICAL water volume within the reservoir)
Water levels in K.R.S. and Kabini reservoirs have
fallen to MDDL level simultaneously which
places water supply to Bengaluru at risk.

13. GROUNDWATER SOURCE FOR BENGALURU
Data source: Central Ground Water Board | Map generated by WRI India for study purpose only
Ground water stress in
and around Bengaluru is
critically high as aquifers
are over-exploited
Groundwater is being used
like an overdrawn credit card that we are not repaying

14. BENGALURU GROWTH 1990-2015
Data source: European Commission JRC; LandSat (USGS/ NASA) | Population for 2015 generated using 4% growth rate over the
2011 Census data | Map generated by WRI India for study purpose only
Bengaluru’s population and built-up area has
doubled in the last 25 years
1990 2000 2010 2015Units
Built-up
Area
230 292 340 453Sq km
Population 4,129,424 5,688,985 8,495,492 9,938,524

15. Data source: LandSat (USGS/ NASA) | Normalized Difference Vegetation Index (NDVI) used to estimate vegetation
changes | Map generated by WRI India for study purpose only
BENGALURU’S OPEN SPACES AND VEGETATION
134
107 103 107
331
299
242
135
0
100
200
300
400
1990 2000 2010 2015
Areainsquare
kilometres
High Density Green Cover Open Space Linear (Open Space)
High density green cover (NDVI Index > 30) has not changed
significantly
Open space has diminished from half of Bengaluru in 1990
to only one-fifth of the city in 2015

16. OPEN SPACE BECOMES BUILT UP AREA
56
51
40
46
80
53
29
14
0
10
20
30
40
50
60
70
80
90
1990 2000 2010 2015
Areainsquaremetres
Per Capita Builtup Area Per Capita Open Space
Per Capita open space decreased by 83%in 25 years

17. OPEN SPACE AND LAKE FLOOD PLAIN BECOMES BUILT UP AREA
Source: Google Earth
Bellandur and surroundings 2003

18. OPEN SPACE AND LAKE FLOOD PLAIN BECOMES BUILT UP AREA
Source: Google Earth
Bellandur and surroundings 2017

19. BENGALURU’S VANISHING WATERS
Data source: European Commission JRC; LandSat (USGS/ NASA) | Map generated by WRI India
for study purpose only
15 11
25
16
154
116
98
30
0
20
40
60
80
100
120
140
160
1990 2000 2010 2015
Areainsquarekilometres
BBMP BMRDA Linear (BMRDA)
80% decrease in surface water bodies within the
Bengaluru metropolitan region

20. BENGALURU TEMPERATURE CHANGES
Maps generated by WRI India for study purpose only
Doddanna
Industrial
Layout
Kaveri Nagar
Nandini
Layout
Peenya
Phase IV
Peenya
Phase I
Peenya
Phase II
PEENYA
INDUSTRIAL AREA
Langford
Town Kalasipalayam
Jayanagar
Lal Bagh
Shanti Nagar
Bus Depot
JAYANAGAR
RESIDENTIAL AREA

21. Image credit: Samrat Basak
BENGALURU’S WATER FUTURE

22. POTENTIAL WATER SCENARIOS FOR BENGALURU
*Business as usual (BAU) | **Demand-supply gap is met through groundwater use at present | Water volumes reported in million litres per day (MLD)
670 920 1050
1140 1575 1800
1930
2730
3110
750 1030 1180
1230 980 850
1165 700 475
1870
1070
690
2018
2025
2031
BAU* (49.25%) 30% 20%
1300 990 840
2021
Surface Water Supply:
Cauvery Stage I to Stage IV
Phase 2
(17 TMC/ Year)
Projected Surface Water
Supply: Cauvery Stage I to
Stage IV Phase 2
(19 TMC/ Year)
Projected Surface Water
Supply: Cauvery Stage I to
Stage V Phase 2
(29 TMC/ Year)
Projected Surface Water
Supply: Cauvery Stage I to
Stage V Phase 2 +
Linganmakki + Etinahole
(29 + 10 + 10 TMC/ Year)
Non-Revenue Water
1234
4321
Legend
Demand-
supply gap**
Surface water
supply

23. Image credit: Interacticity.net
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24. Image credit: http://www.fluidconservation.com/water-networks/