Centre for Science and Environment, New Delhi

MAKING WATER EVERYBODY’S BUSINESSMAKING WATER EVERYBODY’S BUSINESS

JALSWARAJ-JALSWARAJ-

Centre for Science and Environment, New Delhi

Once consisted of group of seven islands called Colaba, Mazagaon, Old woman’s Island, Wadala, Mahim, Parel and Matunga – Sion.

Vehar lake Tulsi Lake

Tansa Dam Vaitarna

INCREASE IN POPULATION

3

12

0

2

4

6

8

10

12

14

1 2

IN M

ILLI

ONS

1951

2002

DEMAND, SUPPLY AND GAP

34002900

500

0

500

1000

1500

2000

2500

3000

3500

4000

1 2 3

SOURCE : MUNICIPAL CORPORATION OF BRIHANMUMBAI

IN M

ILLI

ON L

ITRE

S PE

R DA

Y

PRESENT WATER SOURCE 68

18

455

1044

1365

• BMC has extensive network…

BUT

Distribution is not uniform.

Suburban consumers have to supplement with tankers—spending at least Rs 450 per day

Also quality of tanker water is a major concern.

WHO GETS HOW MUCH…

The amount that goes ‘unaccounted for’…

About 20 to 25 per cent is lost in leakage and pilferage.

GROUNDWATER QUALITY…

SEA WATER INTRUSION – Colaba, Dharvi, Khar, Anderi, Chembur, Malad etc.

INDUSTRIAL POLLUTION – Greater mumbai area

( High Nitrate, trace elements like Cu, Cr, Hg etc are found in water)

Source: Central Ground Water Board

FUTURE DEMAND, SUPPLY AND GAP

5400

33552045

0

1000

2000

3000

4000

5000

6000

1 2 3

SOURCE : BMC

IN M

ILLI

ON L

ITRE

S PE

R DA

Y

MIDDLE VAITARNA STILL WAITING FOR CLEARENCE

• Only 20 per cent of the water is used for drinking, cooking;

• Over 60 per cent is used for bathing, washing and flushing down the toilet. Important that our water toilets are still 10-12 litres per each pull of the chain.

Literally, water down the drain…...80% potable water ends up as waste-

water

And WASTAGE…FLUSHED down the drain

• Only 24 per cent of the wastewater generated by urban India is treated—Mumbai accounts for 23 per cent of the total amount produced

• The rest 76 per cent is disposed of into WATER BODIES (rivers, lakes etc) untreated

• These water bodies are the water sources for the cities in the down stream

WE ALL LIVE DOWNSTREAM

• Water is cheapest in Delhi. 35 per KL as compared to production cost of Rs 6-7 per Kl.

• Mumbai is in a better position, the cost for domestic supply is Rs 2.25 per KL and the production cost is Rs 5.74 per KL

• In Indore the cost for domestic 2.00 per KL and the production cost is Rs 9.50 KL.

• Bangalore charges Rs 5-60 per KL and the production cost is Rs 13 per KL.

But, strangely the supply is almost FREE

Area – 437 sq kmts

Annual avg .rainfall – 2000 mm

Potential - 2394.52 MLD

Present water supply = 2900 MLD

Options:Storage;recycling; and recharge

Even if we assume 70 % of the area to be developed, 50 % of it to be roofed and we collect 70 % of the water falling over it, the quantity of rainwater that can be harvested works out to 589.34 MLD. This is a sizeable quantity compared to water supply to Mumbai. It may also be reminded that the Middle Vaitarna project is for 455 MLD.

WATER HARVESTING POTENTIAL OF MUMBAI

SUCCESS STORIES IN MUMBAI…

BEST BUS DEPOT

TATA INSTITUTE OF SOCIAL SCIENCE

• Reclaimed land and threat of salinity. Quality of water—of both municipal supply and tankers

• Unequal distribution• Wasteful consumption pattern—leading to

overwithdrawal from sources—heading for urban-rural conflict?

Therefore, overall water management is the order of the day—with RWH as a key component

Basic concerns of a Mumbaikar…

• Create informed public opinion…the ALMs can play a key role here

• Training the real users • Strict legislation

Way AHEAD

• Mumbai Municipal Corporation has made rainwater harvesting (RWH) mandatory to the properties having plot area more than 1000 sq. mts.

• This condition will also be made applicable to existing buildings in near future.

• Recycling has been made compulsory for buildings having centralised A C plants.

• BMC will supply 90 LPCD instead of 135 lpcd to ensure RWH will supplement the gap.

Mumbai

Role of the people..

• None of this will work unless….

The citizens make rainwater harvesting their own business