Water Management and the Climate Crisis

In recent years, the global risk reports published by the World Economic Forum have included among the leading factors the adverse climatic effects that our planet faces due to the climate crisis. One, in particular, is the increase in the frequency and impact of extreme weather events. This development is  palpable throughout the world. This summer, for example, Europe and Asia both broke records for high temperatures.

Sudden changes related to water resources have also been observed in Mexico. For example, Nuevo Leon went from having one of the worst droughts in the country's history to suffering a flood problem in less than a month. The increase in population and, consequently, in urban sprawl, has led to unprecedented hydric stress. We require water for practically every aspect of our lives, ranging from satisfying our basic needs to the development of productive activities.

The growth of human development inevitably requires the exploitation of more natural resources, such as water. Consequently, the need for services, such as drinking water supply and wastewater treatment, grows proportionally. This has led to various aquaculture and marine ecosystems being affected, to the point of becoming unsuitable for human consumption, which implies processes and large investments for their treatment and/or purification. Without adequate water management and purification systems, components such as arsenic, fluoride and lead could contaminate drinking water as a result of the degradation of the components used in the water supply.

Available water is understood as that which circulates through rivers and can be deposited in other bodies of water, such as dams or embankments. In Mexico, the water available for productive activities and public supply comes mainly from precipitation, with  an average annual volume of 1,449 cubic kilometers. However, of that volume, 70 percent returns to the atmosphere by evapotranspiration, which is defined as the loss of moisture from a surface by direct evaporation together with the loss of water by transpiration from vegetation.

On the other hand, Mexico receives approximately 48 cubic kilometers through imports from its northern and southern borders and exports 0.43 cubic kilometers annually from the Rio Bravo to the US in accordance with the Treaty on the Distribution of International Waters of 1944. In this way, the average natural availability in Mexico, also called “renewable water,” which is defined as the total volume of surface and underground renewable water that occurs naturally in a region, is 451.6 cubic kilometers of water on average per year.

The availability of renewable water between regions is highly uneven. This means that the availability of water does not coincide with how the population is distributed in the country, or with the regional generation of GDP. In the southeastern part of the country, approximately 67 percent of renewable water is concentrated but only about 23 percent of the national population lives there, contributing around 18 percent of national GDP.

Thus, Mexico’s Valley region has the lowest average annual availability per inhabitant, with only 144 cubic meters per inhabitant per year. In comparison, in the southern zone (mainly Chiapas and Tabasco) the provision is little more than 130 times greater, with 18,776 cubic meters per inhabitant per year.

The decrease in the volume of water per capita in the country has been significant in recent decades, mainly due to population growth and the lack of adequate urban development planning. In the period between 1950 and 2017, volume has fallen by almost 80 percent, from 17,742 to 3,656 cubic meters per inhabitant, and the expectation is for this reduction to continue. The trend indicates that, in the year 2030, volume will be reduced to approximately 3,285 cubic meters per inhabitant.

The increase in population and the subsequent increase in productive activities have generated considerable water stress. One of the relief mechanisms for this additional pressure on typical supply sources, such as lakes and rivers, is through the construction of infrastructure, such as dams and reservoirs, in such a way that they can contribute to reducing the effects of contingencies caused by the natural variability of the water cycle.

Climate change represents an additional challenge to those already presented. Drastic changes, such as droughts, floods and changes in natural precipitation cycles, will only aggravate the already-evidenced economic, social and environmental effects . Without an adequate plan, population growth will exacerbate  water stress and the need to  adopt drastic measures, such as scheduled water cuts, will eventually become a reality.

In Mexico, public policymakers must consider the importance of having a robust water management system in the short term, since, without a doubt, the climate crisis will aggravate the availability of water or generate extreme weather events for which we must build resilience and mechanisms to take advantage of atypical rainfall. Inevitably, water management will be one of the main challenges to overcome in the coming years in our country.