MEXICO CITY METROPOLITAN AREA:
THE LARGEST MEGACITY
IN AN UNSUSTAINABLE PATH
CECILIA TORTAJADA
THIRD WORLD CENTRE FOR
WATER MANAGEMENT, MEXICO
Metropolitan Area of Mexico City
• Area of 4,925 km2
1,484 km2 in Mexico City
3,441 km2 in State of Mexico
• 0.3% of land and 22-25% of
population
16 boroughs of Mexico City
34 municipalities of State of
Mexico
• 45% of commercial, services
and industrial activities
• 32% of the GDP
Population density, Metropolitan Area of Mexico City
N
State of
Mexic o
De nsity population
13,065 – 17,718 people km -2
7,597 – 13,064 people km -2
Federa l District
Bounda ry
3,857 – 7,596 people km -2
2,091 – 3,856 people km -2
153
– 2,990 people
Munic ipa lity
Bounda ry
km -2
Federal
District
Pop ulation growth
W ater dem ands
30,000
70
50
20,000
m3 day-1
thousand
60
10,000
40
30
20
10
0
0
1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
year
year
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 City
230 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
%
INTERNAL
SOURCES
20.0
25.2
45.2
68.5
Wells
19.0
24.8
43.8
66.4
1.0
0.4
1.4
2.1
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
34.8
(52.7%)
31.2
(47.3%)
66.0
100.0
Rivers and
springs
EXTERNAL
SOURCES
TOTAL
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/s
Cutzamala System
1982 – 4 m3/s
1985 – 6 m3/s
1993 – 9 m3/s
1997 – 14 m3/s
$ 23 million/m3
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
Tank No. 3
Barrientos
Tank
Coacalco Tank
Emiliano Zapata Tank
Tuxpan Dam
Cerro Gordo
Tank
Villa Victoria
Dam
Zitácuaro
City
Water Treatment
Plant
El Bosque
Sta. Isabel Tank
Chilesdo
Dam
Dam
Stabilization Pond
Donato Guerra
Ixtapan del Oro
Dam
Valle de Bravo Dam
Mexico City
La Caldera
Tank
Pericos
Tank
Toluca City
Teuhtli Tank
Colorines
Dam
Temascaltepec River
El Tule Dam
De las Cruces Mountains
2800
P.P. 6
Elevation (msl)
2600
2400
Chilesdo Dam, P.P. 5
2200
P.P. 4
Villa Victoria Dam
Water Treatment Plant
Dam
Pumping plant (P.P.)
2000
Piezometric line
P.P. 3
1800
1600
Valle de Bravo Dam, P.P. 2
Colorines Dam, P.P. 1
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
Period
1976 - 1985
50 cm
100 cm
1900 – 1937 : 3-5 cm/year
150 cm
200 cm
250 cm
1938 – 1947 : 16 cm/year
1948 – 1957 : 35 cm/year
1954 – NO EXTRACTION FROM WELLS IN
THE MEXICO CITY SUB-BASIN
Period
1985 - 1987
FROM 1957 – 5 cm/year
10 cm
20 cm
30 cm
40 cm
Source: INEGI, 2004.
Abstraction of water (m3)/subsidence
in 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 coliforms
Bacterias such as Aeromonas, Pseudomonas, Staphylococcus
and 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)
800
Agriculture
700
Agroindustry
600
Rural
Aquaculture
500
Services
400
Industrial
300
Livestock
Urban
200
Multiple
100
Energy
Comercial activities
0
Surface water
Source: CNA, 2004.
Groundwater
Volumes of water abstracted in State of Mexico
(million m3/year)
2,000
1,800
Agriculture
1,600
Agroindustry
1,400
Rural
Aquaculture
1,200
Services
1,000
Industrial
800
Livestock
600
Urban
400
Multiple
200
Energy
Comercial activities
0
Surface water
Source: CNA, 2004.
Groundwater
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
6.81
Source: CNA, 2004.
Wastewater discharges (m3/s)
USE
TOTAL
MEXICO CITY
STATE OF MEXICO
CONCESSIONS
VOLUME
DISCHARGED
CONCESSIONS
VOLUME
DISCHARGED
31
745.48
689
6.81
0.2159 m3/s
23.63 m3/s
45-50 m3/s
Irrigation of 90,000 ha in the Mezquital Valley
23.85 m3/s
Subsidence in D.F. and Infrastructure problems
1910
Mexico City
Gravity Sewage System
Grand Canal
Slope 19 cm/km
6
2
4
3
10
8
5
Tequisquiac Tunnel
6.8
1950
Pumping Sewage System
7.2
6.8
6
2
5
Slope 12 cm/km
4
3
3
4
5
6.2
1970
Pumping Sewage System
Slope 10 cm/km
45
3
1990
Pumping Sewage System
Slope ≈0
Federal District
Interceptors
Central Deep Drainage
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 WATER
MANAGEMENT FOR
MEXICO CITY, 1992
Water supply
Financial self-sufficiency
Metered service
Programme on leakages detection
PRIVATE SECTOR COMPANIES, 1994
Zone
COMPANY
PARTNERS
AREAS
NUMBER OF
CONNECTIONS
A
SAPSA
ICA
CIE. Generale des
eux
Banamex
Gustavo A. Madero
Azcapotzalco
Cuauthemoc
298,557
B
IASA
Brittingham
Severn Trent
Benito Juarez, Coyoacan,
Iztacalco and Venustiano
Carranza
257,825
C
TECSA
Bufete Ind.
Lyonnaise
Bancomer
Iztapalapa, Tlahuac,
Xochimilco and Milpa
Alta
327,408
D
AGUAMEX
Gutza
Northwest water
Tlalpan, Magdalena
Contreras, Alvaro
Obregon, Cuajimalpa and
Miguel 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
9 UPDATE LIST OF USERS AND CONNECTIONS
9 COMPUTARIZED SYSTEM (USERS, CONNECTIONS,
METERS INSTALLED, CONSUMPTION, BILLS,
COLLECTION OF FEES, DEBTS).
9 PROGRAMME ON LEAKES DETECTION.
9 NO EXCEMPTIONS (EDUCATION AND HEALTH
SECTOR).
9 DISCOUNTS: RETIRED PESONNEL HAS ONE-YEAR
RENEWABLE DISCOUNTS. PEOPLE FROM DISTANT
PLACES WITH NO REGULAR SERVICE.
METERS FOR DRINKING WATER, D.F.,
1994-2002
METERS
(THOUSANDS)
TOTAL
TYPE A*
TYPE B
1994
205.2
0.0
205.2
1995
198.8
20.4
219.2
1996
173.6
139.1
312.7
1997
197.6
116.8
314.4
1998
37.8
47.9
85.7
1999
38.7
11.2
49.9
2000
31.4
10.1
41.5
2001
23.8
3.5
27.3
2002
7.2
1.4
8.6
914.1
350.4
1264.5
TOTAL
*METER A, CHEAPER. INSTALLED IN AREAS WHERE THE ECONOMIC RETURN WAS
NOT ASSURED.
Efficiency indicators for drinking water management
in Mexico City
1996
1997
1998
1999
2000
2001
686.6
690.6
691.9
720.2
752.8
752.2
1,477.5
1,620.2
1,644.0
1,681.1
1,7020.0
1,769.1
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
VOLUME OF
DELIVERED WATER
(MILLION OF m3)
USERS WITH BILL
(THOUSANDS)
NO. OF BILLS FOR
METERED SERVICE
(THOUSANDS)
WATER TARIFFS FOR FEDERAL DISTRICT, 2004
(dollars / m3)
Lowest limits
m3/2 months
Highest limit
m3/2 months
Minimum payment
0
10.1
20.1
30.1
50.1
70.1
90.1
120.1
180.1
240.1
420.1
600.1
960.1
1500.1
10
20
30
50
70
90
120
180
240
420
660
960
1 500
beyond
0.1
1.1
2.5
5.0
11.8
18.7
28.5
57.8
131.9
238.3
605.9
177.0
1 948.5
3 545.8
PRICES FOR DOMESTIC USE IN STATE OF MEXICO
1994-2002 (PESOS/M3/BYMONTLY)
GROUP A
WITH METER
(0 to 25m3)
GROUP B
WITH METER
(0 to 25m3)
GROUP A
WITHOUT
METER
Group B
WITHOUT
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 of
Mexico City
290 l/person/day
Munich
128 l/person/day
25 million people
1.4 million customers
48 m3/s wastewater
200-340 m3/s rain
6% water treated
6.5 m3/s wastewater
15 m3/s rain
100% water treated
0.16 EUR
1,22 EUR