Water management in Greater Mexico City

Greater Mexico City (Zona Metropolitana del Valle de México), a metropolitan area with more than 19 million inhabitants including Mexico's capital (Ciudad de México, or CDMX) with about 9 million inhabitants, faces tremendous water challenges. These include groundwater overexploitation, land subsidence,^[1] the risk of major flooding, the impacts of increasing urbanization, poor water quality, inefficient water use, a low share of wastewater treatment, health concerns about the reuse of wastewater in agriculture, and limited cost recovery. Overcoming these challenges is complicated by fragmented responsibilities for water management in Greater Mexico City:

• The Federal government is in charge of regulating the use of water resources, contributing to the financing of investments and supplying bulk water from other basins through the National Water Commission Conagua;
• The State of Mexico provides bulk water, treats wastewater and assists municipalities in providing water and sanitation services in its part of Greater Mexico City;
• 59 municipal governments in the part of Greater Mexico City located in the State of Mexico and one municipality in Hidalgo State are in charge of water distribution and sanitation for their constituents;
• the government of Federal District provides water supply and sanitation services to its constituents through its water department; and
• two irrigation districts in Hidalgo state are in charge of irrigation with wastewater from Greater Mexico City.

Given the size and political importance of Greater Mexico City, a major flood or a major water supply interruption would be a national political crisis potentially threatening the stability of the federal government. The security of water supply and the functioning of the storm water drainage of the metropolitan area thus are major concerns for the local, state, district and federal governments. In response to the challenges outlined above, the Federal Government, the State of Mexico and the Federal District initiated a US$2.8 billion Water Sustainability Program in 2007.

In parallel, the government of the Federal District launched a Green Plan which includes water conservation as an important element. Investments envisaged under both plans include an increase in wastewater treatment, the import of groundwater from irrigated areas North of the city where the groundwater table increased due to irrigation with wastewater, the construction of a major new storm water drainage tunnel, increased water imports from an expansion of the energy-intensive Cutzamala system that pumps water up over more than 1000 meters, and the reduction of non-revenue water from 36% to 25%.