To hear about water crisis in Ethiopia does not surprise, but not many people would expect that Mexico, an industrializing country, is facing serious water challenges. Punctually to the 20th anniversary of Conagua (Mexico’s National Water Commission), Mexico City has to close its water taps: from January until the end of the dry season (April), water supplies will be suspended for three days per month, to alleviate water shortages of Mexico City’s fresh water sources, which due to scarce precipitation, have reached the lowest levels for the past 16 years.
This is certainly not a once-off problem but the first signs of the culmination of two phenomena: immense overexploitation of available water resources not just in Mexico City but across the country and decreasing precipitation due to climatic changes.
With respect to the latter, the Ministry of Environment (SEMARNAT) and the Centre for Atmospheric Sciences of the Universidad Autónoma de México estimate that by 2020 precipitation rates in the Metropolitan Zone of Mexico City could fall by 5% while temperatures may rise by up to 1.2 degrees Celsius, increasing evaporation.
And Mexico City is surely not the only place facing these risks: in fact, the entire centre as well as the North of Mexico exhibits a similar problematic: severe overexploitation of water resources, and impending adverse impacts on water resources due to climate change.
What are the key problems: in Mexico City, it is of course rapid growth of the urban area, significant water losses due to an obsolete water distribution system but especially pollution of water bodies due to untreated release of sewage water. According to Government statistics (INEGI) Mexico’s urban areas generate 243 cubic meters of wastewater per second of which 25% drain off somewhere into the land-/cityscape, and only a third of which is treated. This does not account for leakage of pollutants due to waste and refuse such as Mexico City’s “Bordo Poniente”, the world’s second largest landfill site that receives 12.5 thousand tons of waste on a daily basis. In addition, deforestation and land use change threaten hydrological cycles and the replenishment of aquifers.
What are the solutions?
Mexico City is expecting the start of the construction of what will be the world’s largest water treatment plant, with a capacity of processing 23 cubic meters of water per second. Water treatment, the extension of sewage systems and access to potable water are also the priorities of Conagua. All these measures are of dire importance, yet as long as they are not coupled with activities that tackle not only symptoms but the actual root causes of the problem -pollution and overexploitation, due to bad planning at national and local level- Mexico will be ill-prepared to face water related impacts to climate change.