Water supply and sanitation in Mexico is characterized by achievements and challenges. Among the achievements is a significant increase in access to piped water supply in urban areas (88% to 93%) as well as in rural areas (50% to 74%) between 1990 and 2010. Additionally, a strong nationwide increase in access to improved sanitation (64% to 85%) was observed in the same period.Data on water coverage from the UNICEF/WHO Joint Monitoring Program (JMP) 2010 Other achievements include the existence of a functioning national system to finance water and sanitation infrastructure with a National Water Commission as its apex institution; and the existence of a few well-performing utilities such as Aguas y Drenaje de Monterrey.
The challenges include water scarcity in the northern and central parts of the country; inadequate water service quality (drinking water quality; 55% of Mexicans receiving water only intermittently according to results of the 2000 census); poor technical and commercial efficiency of most utilities (with an average level of non-revenue water of 51% in 2003); an insufficient share of wastewater receiving treatment (36% in 2006); and still inadequate access in rural areas. In addition to on-going investments to expand access, the government has embarked on a large investment program to improve wastewater treatment.
Access
Urban(78% of thepopulation) Rural(22% of thepopulation) TotalWater Improved water source 97% 91% 96% Piped on premises 93% 74% 89%Sanitation Improved sanitation 87% 79% 85% Sewerage (2006 JMP survey & census data) 80% 16% 64% Source: WHO/UNICEF Joint Monitoring Program (JMP/2010). Data for water and Sanitation based on the WHO World Health Survey (2003) and the Census (2000).
Among the achievements is a significant increase in access to piped water supply in urban areas (96.4%) as well as in rural areas (69.4%) as of 2018. Other achievements include the existence of a functioning national system to finance water and sanitation infrastructure with a National Water Commission as its apex institution.
The challenges include water scarcity in the northern and central parts of the country; inadequate water service quality (drinking water quality; 11% of Mexicans receiving water only intermittently as of 2014); poor technical and commercial efficiency of most utilities (with an average level of non-revenue water of 43.2% in 2010); increasing the national percentage of fully sanitized water which at 57%, is considered to not be enough, as the country's theoretically available percentage of water per capita is 60% lower than it was 60 years ago; and the improvement of adequate access in rural areas.
Service quality
Quality of service also leaves much to be desired. The 2000 census indicated that 55% of Mexican households with access to piped water received services on an intermittent basis, in particular in smaller municipalities and poor areas.World Bank Mexico Infrastructure Public Expenditure Review (IPER) 2005, p. 27-31 About 36% of wastewater was being treated in 2006, a share that is more than twice as high as the average for Latin America. Comisión Nacional de Agua (CONAGUA): Estadísticas del agua en México, 2007, p. 99 However, an unknown share of Mexican treatment plants do not comply with norms for effluent discharge.
In many areas, local water pressure is insufficient and/or unreliable. Thus, many houses have a small water tank known as a tinaco on their roofs. Water that accumulates in a basement cistern, known as an ajibe, is pumped up to it to provide pressure through gravity to the rest of the house regardless of pressure in the local system. In some newer homes, however, key appliances have their own pressure systems, Every year millions of cubic meters of wastewater, municipal, industrial and agricultural discharges are discharged into water bodies that are improperly treated or without any treatment. In Mexico, wastewater discharges are classified as municipal (urban and rural public supply) and non-municipal (other uses such as self-supplied industry). According to official figures, 52.7% of the municipal water generated is treated, and 32% of the non-municipal water.
Water use Despite scarce resources in many Mexican regions water consumption is at a high level, partly favored by poor payment rates and low tariffs. In 2006, more than three quarters (76.8%) was used for agriculture, while public supply only used up 13.9%, the remainder being used by thermal power station (5.4%) and industry (3.8%). In 2006, all in all 77.3 billion m3 were consumed in Mexico, of which 10.7 billion m3 were used for domestic consumption. This means that the average domestic use per capita and day was 270 litres.
Water resources
In 2006, 63% of the Mexican water was extracted from surface water, such as rivers or lakes. The remaining 37% came from aquifers. Comisión Nacional de Agua (CONAGUA): Estadísticas del agua en México, 2007, p. 60 Due to the strong growth of population and internal migration toward arid and semi-arid regions, many water resources in North and Central Mexico became overexploited. The UN claims that more than 80% of the world's wastewater that reaches the sea and rivers is untreated. The WHO estimates that some 2 billion people drink drinking water contaminated by excreta, exposing themselves to diseases such as cholera, hepatitis A and dysentery. According to the National Water Commission, groundwater over-extraction is at almost 40 percent of total groundwater use.World Bank, 2006b, p. 1 In addition, CONAGUA estimates that 52% of the superficial water is very polluted, whereas only 9% are in an acceptable condition.World Bank, 2006a: The Lerma-Chapala River Basin, p. 4
Amidst the water crisis occurring in Mexico, Mexico City has been sinking downwards approximately 1 meter every year. Due to years of draining groundwater for public and agricultural use, the negative effects of relying on groundwater has influenced the Mexican government to call attention to a campaign titled "February 2010: The City May Run Out of Water." Mexico continues to pump out groundwater from deeper ground layers, causing the drainage of soil and weak ground. According to the World Health Organization in 2015, approximately 100% of urban populations used at least basic drinking water sources, whereas approximately 94% of rural populations used at least basic drinking-water.
Geological factors
Background
There are three general facts about the evolution in the governance of water pollution: 1) Water quality suffers when there is low investment in environmental controls, little proactive effort in preventing sources of pollution and abandonment of observation systems and monitoring, in addition to the low investment in treatment systems; 2) Population growth and economic development increase the pressure on soil and water. The problem of water quality does not only refer to a lack of investment and political will, but it is also a problem of aligning investments in water quality in order to achieve greater economic growth. 3) Despite progress in addressing the flagrant causes of water pollution, all the nations of the planet face the challenge of changing established practices, as heavy inertia and a stagnant discourse persist in the way of facing the problem (eg no resources, no capacity). Mexico's climate is another big contributor as to why some parts of the country have relatively low accessibility to clean and safe water. First off, the country itself is split between two tropical areas of the globe that make for differing condition in different regions. Mexico's southern half sits in the inter tropical area of the globe and the northern half of it rests in the temperate area. Both these wind zones, Intertropical Convergence Zones and Temperate zones, have different wind patterns that cause dry climates in various parts of the country. Due to the different wind zones, two-thirds of Mexico is considered to be arid to semi-arid as they only receive about 500 mm of rain year round. The other third of the country is categorized as humid and receives more than 2000 mm of rain all year. Most of the areas with limited access to clean water are in the arid and semi-arid regions.
Droughts
Considering most of the Country experiences arid and/or semi-arid conditions, droughts are one of the most common natural disasters in Mexico. Droughts happen when there are low levels of rainfall in a certain area. As a result, droughts significantly impact agricultural production systems that many people all over the world depend on. Droughts are also impacted by high temperatures that dry up pieces of land. Droughts are very common in all of North America and they have 5 levels of intensity. Regions of Mexico which most commonly experience drought-like conditions range from Veracruz, Tabasco, and the Yucatán. In May 2016, 14.3% of land surface area in Mexico experienced dramatic shift in drought levels from moderate to extreme. The month of November is primarily known as the time of year when the wet season ends and the dry season begins. However, in November 2016, regions in the Yucatán peninsula and Tabasco actually had non-stop drought with the previous dry season, regarding it as the 40th driest month ever.
Ground water The groundwater found all over Mexico is used in various different ways. Three ways that groundwater in Mexico is efficiently utilized are in usage, distribution, and consumption. Regarding its usage, groundwater is extremely versatile in Mexico due to its physical characteristics. Since groundwater is mainly stored in aquifers, it is fairly easy to access year round thus, also benefiting the country socio-economically. As far as distribution, as mentioned before, groundwater is stored in various aquifers that makes available practically anytime. To be exact, Mexico has 653 aquifers placed all around the country. This in turn also relates to constitution since, 39% of consumable water in Mexico comes from sources such as aquifers. However, even considering the amount of groundwater resources available in Mexico, in 2016, aquifers mainly in Baja California indicating high level of saline soil and brackish water. 32 aquifers were identified with saltwater intrusion thus, still creating limited access to clean water.
History and recent developments
In pre-conquest Mesoamerica, water was a deified resource that united indigenous communities. Water was thought to have been a gift from the gods and was thus held to a high degree of respect and protection. The indigenous people performed spectacular feats of engineering, creating complex water cultivation systems that both provided water to their large populations and sustainably preserved natural resources. The Spanish approach to water stood in stark contrast to indigenous valuation of water and commitment of environmental protection. Primary sources reveal the Spaniards’ initial awe of the ingenuity and complexity of indigenous water systems, especially the construction of Tenochtitlan (now known as Mexico City), the capital city-state of the Mexica empire that was built in the center of an enormous lake.