MEXICO CITY METROPOLITAN AREA:THE LARGEST MEGACITY

IN AN UNSUSTAINABLE PATH

CECILIA TORTAJADATHIRD WORLD CENTRE FOR

WATER MANAGEMENT, MEXICO

Metropolitan Area of Mexico City

• Area of 4,925 km2

1,484 km2 in Mexico City3,441 km2 in State of Mexico

• 0.3% of land and 22-25% ofpopulation16 boroughs of Mexico City34 municipalities of State of Mexico

• 45% of commercial, servicesand industrial activities

• 32% of the GDP

Population density, Metropolitan Area of Mexico City

Density population

Federal DistrictBoundary

MunicipalityBoundary

13,065 – 17,718 people km -2

7,597 – 13,064 people km -2

3,857 – 7,596 people km-2

2,091 – 3,856 people km -2

153 – 2,990 people km -2

0

10,000

20,000

30,000

1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

year

thou

sand

Population growth

Federal District

State ofMexico

0

10

20

30

40

50

60

70

1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

year

m3 da

y-1

Water dem ands

N

Water needs, Metropolitan Area of Mexico City

9 million people in Mexico City (95.3% have access to water)14 million in State of Mexico (84.2% have access to water)

364 l/person/day in Mexico City230 l/person/day in State of Mexico

290 l/person/day(including industries, services,

unauthorized uses and leakages of 30-40%)

Sources for drinking water for the Metropolitan Area (m3/s)

Mexico City State of Mexico

Total %

INTERNALSOURCES

20.0 25.2 45.2 68.5

Wells 19.0 24.8 43.8 66.4

Rivers andsprings

1.0 0.4 1.4 2.1

EXTERNAL SOURCES

14.8 6.0 20.8 31.5

Cutzamala 9.9 5.0 14.9 22.6

Lerma 4.9 1.0 5.9 8.9

TOTAL 34.8(52.7%)

31.2(47.3%)

66.0 100.0

Source: DGCOH, 1997; CAEM, 2002.

Groundwater abstraction from the aquifer

• Abstraction of 45- 48 m3/s • Natural recharge rate - 20 m3/s

Overexplotation - 25-28 m3/s • Lowering of the water table

and land subsidence at the rate of 10-40 cm/year in some parts of the city

External sources of water

Lerma River 1942 – 4 m3/s 1965-1976 – 14 m3/s

6 m3/sCutzamala System

1982 – 4 m3/s1985 – 6 m3/s1993 – 9 m3/s $ 23 million/m3

1997 – 14 m3/s

Water has to be transferred from more than 150 km away, pumped to a height of more than 1000 m. It requires 102 pumping stations, 17 tunnels and 8 km of canals, becoming a very energy-expensive operation

2800

1600

2600

2400

2200

2000

1800

Elev

atio

n(m

sl)

Colorines Dam, P.P. 1Valle de Bravo Dam, P.P. 2

P.P. 3

P.P. 4Chilesdo Dam, P.P. 5

Villa Victoria DamWater Treatment Plant

P.P. 6

DamPumping plant (P.P.)Piezometric line

De las Cruces Mountains

Tuxpan Dam

El BosqueDam

ZitácuaroCity

Ixtapan del OroDam

ColorinesDam

El Tule Dam

Valle de Bravo Dam

ChilesdoDam

Villa VictoriaDam

Temascaltepec River

Toluca City

Mexico City

Emiliano Zapata Tank

Tank No. 3

PericosTank

Sta. Isabel Tank

Stabilization PondDonato Guerra

Teuhtli Tank

Cerro GordoTank

La CalderaTank

Coacalco Tank

BarrientosTank

Water TreatmentPlant

Source: Tortajada, 2003.

Cutzamala System - Cost

Only the construction of Cutzalama system ($1300 million) was higher than the national investment in the entire public sector in Mexico in 1996, including:

• education ($700 million) • health and social security ($400 million) • agriculture, livestock and rural development

($105 million) • tourism ($50 million) and • marine sector ($60 million).

Source: CNA, 1997.

Infrastructure for water distribution, State of Mexico, 2004

5,259 l/s are distributed to 10 municipalities of the metropolitan area

60.8 km (42%) out of 143.4 km have been constructed

Land subsidence in the Federal District

Period1976 - 1985

50 cm

100 cm1900 – 1937 : 3-5 cm/year

1938 – 1947 : 16 cm/year

1948 – 1957 : 35 cm/year

1954 – NO EXTRACTION FROM WELLS IN THE MEXICO CITY SUB-BASIN

FROM 1957 – 5 cm/year

150 cm

200 cm

250 cm

Period1985 - 1987

10 cm

20 cm

30 cm

40 cm

Source: INEGI, 2004.

Abstraction of water (m3)/subsidencein Mexico City

•Damages to the infrastructures for water supply and sewerage systems

•Construction of costly pumping systems to remove rainwater and wastewater from the City

•Degradation of groundwater quality

Source: Lesser & Cortés, 1998.

Subsidence in Mexico City

City centre, 10 cm

Airport, 20-25 cm

Source: Mazari-Hiriart et al., 2001.

Problems...

Flooding

Difference in levels between some parts of the City and the collectors

Inability of the overall system to pump all the water out of the City in rainy season

Due to the subsidence of the City, downtown is 7 m below the highest point of the Grand Canal, which makes it difficult for the water to be pumped out of the area

Problems...

Pollution of groundwater

Faecal coliformsBacterias such as Aeromonas, Pseudomonas, Staphylococcusand Vibrio in the southern and eastern part of the City

Helicobacter pylory, related to ulcers and stomach cancer in the aquifer in the area of Xochimilco and in water of Cutzamala before being treated.

Volumes of water abstracted in Mexico City(million m3/year)

0

100

200

300

400

500

600

700

800

Surface water Groundwater

Agriculture

Agroindustry

Rural

Aquaculture

Services

Industrial

Livestock

Urban

Multiple

Energy

Comercial activities

Source: CNA, 2004.

Volumes of water abstracted in State of Mexico(million m3/year)

0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

2,000

Surface water Groundwater

Agriculture

Agroindustry

Rural

Aquaculture

Services

Industrial

Livestock

Urban

Multiple

Energy

Comercial activities

Source: CNA, 2004.

Total volume of water abstracted (million m3/year) and number of concessions

USE MEXICO CITY STATE OF MEXICO

CONCESSIONS VOLUME ABSTRACTED

CONCESSIONS VOLUME ABSTRACTED

AGRICULTURE 2 0.37 1,729 872

AGROINDUSTRY 0 0 1 0.012

DOMESTIC (one user) 3 0.017 159 5.6

AQUACULTURE 2 0.2 153 142

SERVICES 42 5.2 84 21.6

INDUSTRIAL 157 29.3 503 145.9

LIVESTOCK 0 0 82 4.1

URBAN 1 1,089.6 1,865 1,157

MULTIPLE 4 0.7 482 201.4

ENERGY 0 0 4 1,998.9

COMMERCIAL ACTIVITIES

0 0 0 0

Source: CNA, 2004.

Total volume of water abstracted (million m3/year) and number of concessions

USE MEXICO CITY STATE OF MEXICO

CONCESSIONS VOLUME ABSTRACTED

CONCESSIONS VOLUME ABSTRACTED

AGRICULTURE 2 0.37 1,729 872

AGROINDUSTRY 0 0 1 0.012

DOMESTIC (one user) 3 0.017 159 5.6

AQUACULTURE 2 0.2 153 142

SERVICES 42 5.2 84 21.6

INDUSTRIAL 157 29.3 503 145.9

LIVESTOCK 0 0 82 4.1

URBAN 1 1,089.6 1,865 1,157

MULTIPLE 4 0.7 482 201.4

ENERGY 0 0 4 1,998.9

COMMERCIAL ACTIVITIES

0 0 0 0

Source: CNA, 2004.

Total volume of water abstracted (million m3/year) and number of concessions

USE MEXICO CITY STATE OF MEXICO

CONCESSIONS VOLUME ABSTRACTED

CONCESSIONS VOLUME ABSTRACTED

AGRICULTURE 2 0.37 1,729 872

AGROINDUSTRY 0 0 1 0.012

DOMESTIC (one user) 3 0.017 159 5.6

AQUACULTURE 2 0.2 153 142

SERVICES 42 5.2 84 21.6

INDUSTRIAL 157 29.3 503 145.9

LIVESTOCK 0 0 82 4.1

URBAN 1 1,089.6 1,865 1,157

MULTIPLE 4 0.7 482 201.4

ENERGY 0 0 4 1,998.9

COMMERCIAL ACTIVITIES

0 0 0 0

Source: CNA, 2004.

Total volume of water abstracted (million m3/year) and number of concessions

USE MEXICO CITY STATE OF MEXICO

CONCESSIONS VOLUME ABSTRACTED

CONCESSIONS VOLUME ABSTRACTED

AGRICULTURE 2 0.37 1,729 872

AGROINDUSTRY 0 0 1 0.012

DOMESTIC (one user) 3 0.017 159 5.6

AQUACULTURE 2 0.2 153 142

SERVICES 42 5.2 84 21.6

INDUSTRIAL 157 29.3 503 145.9

LIVESTOCK 0 0 82 4.1

URBAN 1 1,089.6 1,865 1,157

MULTIPLE 4 0.7 482 201.4

ENERGY 0 0 4 1,998.9

COMMERCIAL ACTIVITIES

0 0 0 0

Source: CNA, 2004.

Total volume of wastewater discharged (million m3/year) and number of concessions

USE MEXICO CITY STATE OF MEXICO

CONCESSIONS VOLUME DISCHARGED

CONCESSIONS VOLUME DISCHARGED

AGRICULTURE 0 0 261 4.2

AGROINDUSTRY 0 0 0 0

DOMESTIC (one user) 0 0 89 0.04

AQUACULTURE 0 0 3 0.02

SERVICES 22 1.18 282 2.38

INDUSTRIAL 8 0.6 22 0.002

LIVESTOCK 0 0 11 0.16

URBAN 1 744.3 4 0.004

MULTIPLE 0 0 3482 0.003

ENERGY 0 0 0 0

COMMERCIAL ACTIVITIES

0 0 14 0.001

TOTAL 31 745.48 689 6.81Source: CNA, 2004.

Wastewater discharges (m3/s)

USE MEXICO CITY STATE OF MEXICO

CONCESSIONS VOLUME DISCHARGED

CONCESSIONS VOLUME DISCHARGED

TOTAL 31 745.48 689 6.81

23.63 m3/s 0.2159 m3/s

23.85 m3/s45-50 m3/s

Irrigation of 90,000 ha in the Mezquital Valley

Subsidence in D.F. and Infrastructure problems

Federal District

2

3 4 5

6

6.8

7.2810

345

6.8

6

2 6.2

345

54

3

1910Mexico City Tequisquiac Tunnel

1950

Grand CanalSlope 19 cm/km

Gravity Sewage System

Slope 12 cm/km

Pumping Sewage System

1970

1990

Slope ≈0

InterceptorsCentral Deep Drainage

Slope 10 cm/km

Pumping Sewage System

Pumping Sewage System

Source: National Research Council, 1995.

Water Management Constraints

• Old infrastructure• Over-explotation of the aquifer (land subsidence)• Dependence on water supply from outside sources• About 30-40% of water is lost from the distribution

networks due to leakages which could provide water to 4 million people

• Metering is almost non-existent (flat rates)• Only about 18-20% of users pay their water bills• Institutional arrangements

STRATEGY FOR WATERMANAGEMENT FOR MEXICO CITY, 1992

Water supplyFinancial self-sufficiency

Metered serviceProgramme on leakages detection

PRIVATE SECTOR COMPANIES, 1994

Zone COMPANY PARTNERS AREAS NUMBER OFCONNECTIONS

A SAPSA ICACIE. Generale des euxBanamex

Gustavo A. MaderoAzcapotzalcoCuauthemoc

298,557

B IASA BrittinghamSevern Trent

Benito Juarez, Coyoacan, Iztacalco and VenustianoCarranza

257,825

C TECSA Bufete Ind.LyonnaiseBancomer

Iztapalapa, Tlahuac, Xochimilco and Milpa Alta

327,408

D AGUAMEX GutzaNorthwest water

Tlalpan, Magdalena Contreras, Alvaro Obregon, Cuajimalpa andMiguel Hidalgo

263,789

Source: CADF, 1994.

ACTIVITIES

1. SERVICE TO CLIENTS: METERS, READING, DISTRIBUTION OF BILLS, COLLECTION OF FEES, INFORMATION OFFICES.

2. HUMAN RESOURCES AND SYSTEMS (QUALITY CONTROL).

3. TECHNICAL SERVICES: STATISTICS OF USERS AND NETWORKS, REPLACEMENT OF METERS.

4. OPERATIONS: MAINTENANCE OF METERS AND PIPES (LEAK DETECTION AND REPAIR).

RESULTS

UPDATE LIST OF USERS AND CONNECTIONS

COMPUTARIZED SYSTEM (USERS, CONNECTIONS, METERS INSTALLED, CONSUMPTION, BILLS, COLLECTION OF FEES, DEBTS).

PROGRAMME ON LEAKES DETECTION.

NO EXCEMPTIONS (EDUCATION AND HEALTH SECTOR).

DISCOUNTS: RETIRED PESONNEL HAS ONE-YEAR RENEWABLE DISCOUNTS. PEOPLE FROM DISTANT PLACES WITH NO REGULAR SERVICE.

METERS FOR DRINKING WATER, D.F., 1994-2002

*METER A, CHEAPER. INSTALLED IN AREAS WHERE THE ECONOMIC RETURN WAS NOT ASSURED.

METERS(THOUSANDS)

TOTAL

TYPE A* TYPE B1994 205.2 0.0 205.21995 198.8 20.4 219.21996 173.6 139.1 312.71997 197.6 116.8 314.41998 37.8 47.9 85.71999 38.7 11.2 49.92000 31.4 10.1 41.52001 23.8 3.5 27.32002 7.2 1.4 8.6TOTAL 914.1 350.4 1264.5

Efficiency indicators for drinking water managementin Mexico City

1996 1997 1998 1999 2000 2001

VOLUME OF DELIVERED WATER(MILLION OF m3)

686.6 690.6 691.9 720.2 752.8 752.2

USERS WITH BILL(THOUSANDS)

1,477.5 1,620.2 1,644.0 1,681.1 1,7020.0 1,769.1

NO. OF BILLS FOR METERED SERVICE(THOUSANDS)

725.6 1,260.6 1,408.3 1,505.1 1,552.8 1,582.7

CHARGED WATER (BILLION PESOS)

1.1 1.5 2.1 4.6 2.8 3.2

BILLED WATER (BILLION PESOS)

1.7 2.4 2.7 7.2 3.5 3.8

WATER TARIFFS FOR FEDERAL DISTRICT, 2004(dollars / m3)

Lowest limitsm3/2 months

Highest limitm3/2 months

Minimum payment

010.120.130.150.170.190.1120.1180.1240.1420.1600.1960.11500.1

102030507090120180240420660960

1 500beyond

0.11.12.55.011.818.728.557.8131.9238.3605.9177.0

1 948.53 545.8

PRICES FOR DOMESTIC USE IN STATE OF MEXICO1994-2002 (PESOS/M3/BYMONTLY)

GROUP A WITH METER

(0 to 25m3)

GROUP BWITH METER

(0 to 25m3)

GROUP AWITHOUT METER

Group BWITHOUT METER

1994 0.56 0.45 47.82 38.3

1995 0.63 0.5 53.56 42.9

1996 0.88 0.7 74.98 60.06

1997 1.01 0.81 85.5 69.5

1998 1.16 1.02 99.8 87.39

1999 1.31 1.15 112.65 98.51

2000 1.44 1.26 123.93 108.39

2001 1.53 1.37 131.94 117.19

2002 1.69 1.46 137.83 118.27

Source: CAEM, 2002; 1994-2002: Ley de Hacienda del Estado de México; 1999-2002: Código Financiero del Estado de México y Municipios.

Metropolitan Area ofMexico City

Munich

290 l/person/day 128 l/person/day

25 million people 1.4 million customers

48 m3/s wastewater200-340 m3/s rain

6.5 m3/s wastewater15 m3/s rain

6% water treated 100% water treated

0.16 EUR 1,22 EUR