Water Resources Management
at the Mexican Boundary with
the USA
Javier Aparicio
Mexican Institute of Water Technology
Ministry of Environment and Natural Resources
México
Instituto Mexicano de Tecnología del Agua
Deals primarily with water related issues in
order to help reaching the sustainable
development for the country, by conducting
research and technological development (R&D)
in collaboration with public and private
institutions, universities and other research
centers such as NGO’s.
Four main research divisions
• Hydrology
• Water Quality
• Irrigation and drainage
• Hydraulics
• Professional development
In the near future, it is expected
that conflicts between neighbour
municipalities, counties and even
countries will be related to water.
To avoid that, it is necessary to
create transboundary water use
policies in which all the parts
involved agree to make the
efficient use and proper long and
short term planning.
México/USA Boundary
• 3000 km
• 14 cities
• 10.6 million in 2000
• 55% US, 45%
México
• 14 million in 2020
Watersheds México/USA
TIJUANA RIVER WATERSHED
TOTAL = 4,424 km2
U S A = 1,221 km2
MEXICO = 3,203 km2
WYOMING
COLORADO RIVER WATERSHED
TOTAL = 634,840 km2
U S A = 631,000 km2
MEXICO = 3,840 km2
UTAH
NEVADA
COLORADO
CALIFORNIA
SONORA
CHIHUAHUA
PACIFIC
OCEAN
BRAVO/GRANDE RIVER WATERSHED
NUEVO
MEXICO
ARIZONA
TOTAL = 444,560 km2
U S A = 229,798 km2
MEXICO = 214,762 km2
TEXAS
COAHUILA
N
DURANGO
NUEVO
LEON
GULF
OF
MEXICO
1944 Treaty
Colorado River
• 634,840 km2
• 7 USA States:
Colorado River
compact
• 2 Mexican States
Gulf of California or
Gulf of Cortés
Colorado River flows
Hoover Dam
Glen Canyon Dam
1000 acre-ft=1.233 hm3
•One of the most
exploited rivers in the
world: 20,700 
5,200 hm3 in 100
years
•Nearly 100% of
water is used for
agriculture & urban
supply
•1,850.2 hm3/yr to
México; 2097 when
there are excedents
•Droughts are shared
Droughts, Colorado River
• In case of extraordinary drought or a
serious accident in the irrigation system in
the USA which would prevent delivering the
guaranteed volume, the assigned volumes
to Mexico would be reduced in the same
proportion as the consumption reduction in
the USA.
Colorado River: Salinity
• Salinity not in the Treaty
• 1961: Increase in salinity
above 2,500 ppm
Imperial dam
Imperial Valley
Morelos dam
Mexicali Valley
San Luis Río
Colorado
• IBWC Negotiations: Act
242 (1973)
• Bypass channel
• Salinity < Imperial Dam
+121 ppm; higher at San
Luis
Colorado River: Salinity
San Luis
Morelos
Imperial
Source: CILA
Delta Region
Before 1930
70´s and 80´s
• One of the biggest
desert estuaries in
the world
• 780 000 ha
• Highly diversified
collection of
plants, birds and
marine species
•Dry and dead
system of small
wetlands and
salt marshes
•Highly
salinized desert
Last 2 decades
• Floods, surplus,
return flows
• 60 000 ha restoration
• Significant wetland
ecosystem in SW
USA and NW
México in danger
Delta Region
Near future
SALTON
SEA
IMPERIAL VALLEY
LAGUNA
SALADA
MEXICALI
VALLEY
SANTA CLARA
SLOUGH
ALTAR DESERT
SEA
OF CORTÉS
• Significant population
increase
• Pressure over land,
water and other
resources
• Permanent flows vs.
Interim Surplus Criteria
• Legal issues
Actions
• Establishment of the Alto Golfo de California y Delta del
Río Colorado Biosphere Reserve
• Wastewater treatment plants in Border Cities and recycling
• Efficient water use programs
• Legal framework modifications: New National Water Law
– Ecological priority
– Incentives to water consumption reduction
• Program Border XXI
– Public participation
– Capacity building
– Interinstitutional cooperation
• Binational workgroups for R&D
Bravo/Grande River
• Boundary: 2,001 km
• Total runoff : 11,000
hm3/year
• Total storage capacity:
23,000 hm3
• 1944 Treaty: Fort
Quitman to mouth
Agricultural use, Bravo Basin
DR CD
JUÁREZ 009
Fort Quitman
DR BAJO RÍO
CONCHOS 090
P LUIS L. LEÓN
DR DELICIAS
005
P FRANCISCO I. MADERO
P LA BOQUILLA
P LA AMISTAD
DR PALESTINA
006
DR DON
MARTÍN
004
DR ACUÑA
FALCÓN 050
DR RÍO
FLORIDO 103
P SAN GABRIEL
P FALCÓN
LAS
LAJAS
031
DR BAJO RÍO
SAN JUAN 026
P MARTE R. GÓMEZ
P EL CUCHILLO
DR BAJO RÍO
BRAVO 025
Bravo/Grande River
USA
1/2
1/2
Bravo/Grande
Fort
Quitman
La Amistad
Dam
1/2
Falcón Dam
Gulf of
México
1/2
•74 hm3/yr at Juárez (1906)
•431.7 hm3/yr in 5-yr cycles
•1953-2002: 26 periods
Gauged rivers
•Cycle 25 completed in 2001
1/3 US
•Deficit in cycle 26
2/3 México
•Droughts are not shared
Droughts, Bravo/Grande River
• In case of extraordinary drought or a
serious accident in the Mexican hydraulic
system which would prevent Mexico to
deliver such volume, any undelivered
volume at the end of the 5-year period
would be distributed in the following
period with water from the same tributaries.
Actions
• Wastewater treatment plants
in Border Cities
• Efficient water use programs
• Binational workgroups for
R&D
• Río Bravo water distribution
rule
• Irrigation modernization and
technology improvement in
Conchos River Basin
Río Bravo water distribution rule
• Define Extraordinary drought
• Distribute US assignment
among Mexican tributaries
• Propose to subject deliveries to
US with the same deficit
restrictions as Mexican
irrigation assignments
• Consensus building on
distribution rule among users
Modernization and technology
improvement, Conchos Basin
•Channels and network lining
•Control structures and wells rehabilitation
•Low pressure, drip and sprinkler systems
•Land leveling
•Real-time irrigation forecast
•Efficiency: 33  55%
•Recover 396 hm3/yr in 4 years
•2002-2006, US $150 million
•NADBank Fund and Federal investment
Water quality, Tijuana
• 32 hm3 of treated
residual water with
organic contaminants to
the Pacific Ocean
• Industrial residuals
discharges 8 hm3/year.
• Volumes generated are
higher than plant
capacity: serious
pollution problems
Transboundary aquifers
1
N
2
3
4
5
6
Mapa de la región
7
Sonora
Chihuahua
Coahuila
1. Mexicali Valley
2. Sonoita River
3. Santa Cruz River
4. San Pedro River
5. Conejos-Médano aquifer
6. Juárez Valley
7. La Amistad observation wells
Tamaulipas
• Mexicali: Recharge/
exploitation: 150/ 102
hm3; All-American
channel lining?
• Juárez Valley:
Drawdowns > 45 m;
quality problems
Conclusions
• México and USA share a politically,
sociologically and hydrologically complex
and rapidly evolving boundary
• International agreements have been the
result of long negotiations made in good
will and with the benefits of both countries
in mind: examples by other Countries
Conclusions
• Population growth and comprehensive water use:
careful joint water resources management in the
boundaries
• Sustainable development binational plans, including
Colorado Delta ecology
• Integrated international hydrometeorological
information system along the Border
• Efficient water use programs
• Binational R&D programs