Water resources management in Mexico
The country has in place a system of water resources management that includes both central (federal) and decentralized (basin and local) institutions.
The arid northwest and central regions contain 77% of Mexico's population and generate 87% of the gross domestic product (GDP).
Surface and groundwater resources are overall overexploited and polluted thus leading to an insufficient water availability to support economic development and environmental sustainability.
The 1934 Código Agrario, promulgated during the Cárdenas administration (1934–1940), granted the federal government powers to define the "public interest" to which water could be harnessed.
Over time, large landowners became highly capitalized, while small land owners, by the 1970s, were suffering from the effects of water monopolies.
In 1992, Mexico adopted the Ley de Aguas Nacionales (LAN), which contained specific provisions for the role of the CONAGUA, the structure and functioning of river basin councils, public participation in water management, etc.
Total internal renewable water resources are 457 billion cubic meters (BCM)/year, plus 49 BCM/year inflows from neighboring countries (average 1977–2001).
This average rate does not fully represent the situation of the arid region, where a negative balance is threatening the sustainable use of groundwater resources.
[11] Mexico has 4,000 dams and other hydraulic infrastructure with a storage capacity of 180 cubic kilometres (43 cu mi), which account for 44% of the annual flow.
By far the largest and most important is Chapala Lake between the states of Jalisco and Michoacán with an area of 1,116 km2 and a storage capacity of 8,126 cubic hectometres (1.950 cu mi).
During the past decade, the Mexican water supply and sanitation sector made major strides in service coverage.
Cenotes, sinkholes on the Yucatan peninsula that are filled with groundwater, host a number of unique species from bacteria, algae and protozoa (i.e. copepoda, cladocera and rotifera) to vertebrates (i.e.lepisosteus).
[23][24] According to the LAN key functions in the sector are the responsibility of the federal government, through the National Water Commission (CNA or CONAGUA).
It also directly manages certain key hydraulic facilities such as the Cutzamala Pipeline that supplies a large share of the water used in the Metropolitan Area of Mexico City.
The LAN made possible to implement a regulatory framework that seeks to encourage greater efficiency and a more accurate perception of the social, economic, and environmental value of water resources.
Therefore, waters users operate within a framework of rights and obligations that are clearly defined in three basic instruments: The 2004 amended National Water Law (NWL) aims to restructure CONAGUA key functions through the transfer of responsibilities from the central level to subnational entities: the basin agencies (Organismos de Cuenca – BA) and Basin Councils (Consejos de Cuenca – BC).
CONAGUA will create together with the Ministry of Finance appropriate instruments to determine funding sources, spending guidelines, cost recovery, settling of accounts and management indicators.
Three groups of institutions have been assigned with the main responsibilities for WRM: (i) the National Water Commission (Comisión Nacional del Agua –CONAGUA), at the federal level; (ii) Water Commissions (Comisiones Estatales del Agua – CEAs), at the State level; and (iii) basin authorities and basin councils.
CONAGUA is formally under the authority of the Ministry of Environment and Natural Resources (Secretaria del Medio Ambiente y Recursos Naturales – SEMARNAT) but it enjoys considerable de facto autonomy.
It also directly manages certain key hydraulic facilities such as the Cutzamala Pipeline that supplies a large share of the water used in the Metropolitan Area of Mexico City.
CONAGUA will create together with the Ministry of Finance appropriate instruments to determine funding sources, spending guidelines, cost recovery, settling of accounts and management indicators.
The NWP has a total budget of 227,130 million pesos (about US$21.9 billion), which does not include operational and maintenance costs of hydraulic infrastructure.
Mexico lacks a coherent national policy framework for setting and linking water and sanitation tariffs, subsidies and cost-recovery goals.
Hurricanes contribute to recharge surface and groundwater reservoirs with increases water supply for cities, irrigation and electricity generation.
For example, in the Lerma-Chapala basin the predicted increase in temperature coupled with a decrease in rainfall could result in severe water supply shortages, exacerbated by growth in population and industries.
The most severe droughts in Mexico in recent decades coincide with the variations in Pacific sea-surface temperatures associated with El Niño.
In 1996, four years of below normal rainfall produced farms losses estimated at US$1 billion and interstate political between Sonora and Sinaloa.
[31] During some El Niño/La Niña years, winter precipitation may be so great that stream flow and water levels in dams may exceed those observed during summer.
[32] In 2007, SEMARNAT together with the Instituto Mexicano de Tecnología del Agua published a study "Climate Change Effects on Water Resources in Mexico."
[33] This project aims at formulating and implementing adaptation policy actions and specific measures in representative systems of Gulf of Mexico wetlands in order to protect their environmental functions and their rich biodiversity from climate change related impacts, and improving the knowledge base to ascertain with a higher level of certainty the anticipated impacts from climate change on the country's water resources, with a primary focus on coastal wetlands and associated inland basins.
