Voices of Mexico 108  Fernando J. González Villarreal* Jorge Alberto Arriaga Medina** Managing Groundwater in Mexico Introduction Water is essential for human and ecosystem development. without endangering ecosystem health. By 2015, 147 coun- Both our present and our future depend on its conserva- tries had reduced the number of people without access tion and efficient use. Sufficient quality water for everyone to potable water by half, and 95 more nations did the is indispensable for sustainable development. The plan- same for sanitation services. The Millennium Development et has enough fresh water to achieve this; however, chal- Goals successes show that worldwide actions actually lenges continue to be posed that demand an immediate work and that the way forward for ensuring sustainable response with creative, innovative solutions involving development involves international cooperation and dif- everyone. ferent sectors joining forces. The international community has done great deal of Despite the big advances, however, important chal- work to contribute to water resource sustainability and lenges persist. Water scarcity continues to affect more ensure equitable access to drinking water and sanitation than 40 percent of the world’s population, and this figure is expected to rise as a result of climate change. The degradation of our water resources affects marginalized pop- * Researcher at the unam Institute for Engineering; fgv@pumas.iingen.unam.mx. ** Coordinator of the unam Hydrological Observatory; jarria gam@iingen.unam.mx. 62 ulations more than the rest since they depend directly on nature for their subsistence and their settlements are concentrated in high-risk areas.  Do ssi er Water Given this variability, groundwater has played a central Water scarcity continues to affect more than 40 percent of the world’s population, and this figure is expected to rise as a result of climate change. role in Mexico’s development. Our country’s 653 aquifers irrigate more than 2 million hectares, and supply more than 70 percent of cities and 50 percent of industry. Having balanced aquifers is indispensable for achieving food security, ensuring the availability of water during droughts, stopping subsidence, increasing the amount of water, The World’s Groundwater and maintaining a balance with surface water. Changing the paradigm worldwide for water management exploitation. The lack of information about its character- in general and groundwater in particular is undoubtedly istics and behavior, together with the dearth of effective necessary. Improving the system creates better conditions management instruments, contribute to the deterioration for achieving sustainable development, and by contrast, of its quality. These factors also negatively impact eco- maintaining the current rhythm of overexploitation threat- systems because natural springs and wetlands disappear, ens the security of the economy, the ecosystems, and and, with them, the fauna and vegetation that depend on people themselves. them. The reduction in groundwater levels makes extrac- Groundwater is a common resource susceptible to over- The United Nations estimates the world’s total volume tion increasingly difficult, requiring new technologies and of groundwater at 13.3 million to 60 million cubic kilo- increasing investment. Together with this, we are facing meters. It is the main source of water for agriculture (67 problems of subsiding and cracking soil, which endangers percent), followed by its use for public urban consump- the security of transportation and hydraulic infrastructure, tion (22 percent), and finally, self-supply for industry (11 among other kinds, and that of people themselves. percent). Over the last 50 years, groundwater extraction Considering the importance of groundwater for achiev- has tripled and is increasing at a rate between 1 and 2 ing the Sustainable Development Goals, the unam Water percent annually. This is due mainly to its consumption Network, in coordination with the National Water Com- in countries like India, China, the United States, and Pak- mission and other institutions, called on the international istan, which use about 50 percent of all the groundwater community to exchange experiences for more efficient, extracted. sustainable management of aquifers at the 9th International Symposium on Managed Aquifer Recharge, held in Mexico. The outcome was the following six directives for Groundwater in Mexico sustainable groundwater management. Mexico is no exception. Its hydrological conditions are very diverse, contributing to enriching our natural and cultural heritage, but also increasing our vulnerability to Sustainable Groundwater Management Directives1 the effects of extreme hydro-weather phenomena, such as droughts and flooding, and posing challenges for sus- 1. Recognize aquifers and groundwater as critically important, tainable water management. Although the central and finite, valuable, and vulnerable resources northern parts of the country produce 87 percent of the Aquifers are valuable geological, hydrologically inter- country’s gross domestic product and concentrate about connected systems through which groundwater circu- 77 percent of the population, they only enjoy 31 percent lates or is stored. They mitigate 50 percent of the world’s of the water resources. The South, on the other hand, with water needs and make water supplies resilient during its abundant water supplies (69 percent of those avail- droughts. This underground water is a limited resource able), has a smaller population and contributes less to and, in many places is strongly connected to surface wa- overall national wealth. These spatial variations combine ter bodies. Many aquifers contain very old groundwater with seasonal changes, since 68 percent of annual pre- deposited thousands of years ago and are nonrenewable cipitation falls between June and September. unless purposefully recharged. Since groundwater is un- 63 Voices of Mexico 108  The degradation of our water resources affects marginalized populations more than the rest since they depend directly on nature for their subsistence. derground, it is not visible and generally not well under- improve understanding over time. Needed also are con- stood. tinued efforts to improve tools and innovative technologies for less costly and higher value information. The 2. Halt the chronic depletion of groundwater in aquifers on a government and private industry can help provide the re- global basis sources to support academia to train the future work- Today, groundwater supplies in many of the world’s force, managers and scientists, and researchers to develop aquifers are unsustainable, resulting from overexploitation improved tools and technologies. Finally, the knowledge and a lack of proactive management. Evidence of deple- and data on aquifer systems should be shared widely so tion includes chronically declining groundwater levels, that groundwater is invisible no more. loss of groundwater storage, water quality degradation, land surface subsidence, seawater intrusion, surface wa- 4. Groundwater must be sustainably managed and protected, ter depletion and loss of springs, base flow, and associ- within an integrated water resource framework ated groundwater dependent ecosystems. Depletion can Sustainable management of groundwater includes cause irreversible damage and deprive future generations increasing and sustained investment in groundwater, ap- of the resource. Actions need to be taken immediately to propriate policies and regulations, legal framework, in- invest the required resources to regulate and actively man- stitutions with sufficient authority and accountability, age groundwater quantity and quality as needed to halt and development and implementation of comprehen- chronic depletion, water quality degradation, and achieve sive and adaptable management plans. The legal frame- sustainability in the next 25 years. work should address the process and actions for assigning, accounting, and allocating water rights, and the mecha- 3. Aquifer systems are unique, need to be well understood, and groundwater should be invisible no more nism for resolving conflicts and disputes. Groundwater management institutions should cover All aquifer systems are unique and diverse in physical the entirety of each aquifer system, including recharge characteristics and other features. As such, aquifer sys- source areas and connected surface water systems, and tems can be complex, difficult, and expensive to evaluate, should have the authority and accountability to sustain- but must be well understood for effective management. ably manage groundwater. The groundwater management Increasing the knowledge of aquifers is essential to de- institutions should consider the interests of all beneficial veloping a foundation for sustainable management of uses and users of groundwater, and be integrated with groundwater resources. The basic elements include, but surface water management institutions to manage con- are not limited to, the nature of the aquifer geometry and nected systems. Institutions should have the authority chemical and physical characteristics, local hydrologic to conduct studies, register and monitor wells, measure cycle and interconnectedness of aquifers, confining layers and regulate extraction, implement capital projects, free- (aquitards) and overlying local and regional surface wa- ly share data and information, and assess fees to cover ter systems, groundwater flowpaths and gradients, water the cost of groundwater sustainability. Responsible man- budget and availability, current and future demands on the agement institutions should ensure that all share the system, and an assessment of how land uses and climate cost of groundwater sustainability equitably. Federal or change may affect local hydrology and water quality. state governments should provide the backstop and in- This information is expensive to collect, and significant tervention as necessary if groundwater management in- investments of resources are needed to increase inde- stitutions are unsuccessful in sustainably managing pendent data collection and dissemination in order to groundwater in their jurisdictional areas. 64  Do ssi er Water Mexico’s hydrological conditions are very diverse, contributing to enriching our natural and cultural heritage, but also increasing our vulnerability to the effects of extreme hydro-weather phenomena. Management plans should include a sustainability Groundwater is a shared, local resource, and collabo- goal, measurable objectives, an adequate understanding ration and robust participation of community stakeholders of the physical system and hydrology, monitoring pro- and leadership overlying the aquifer system, including gram and protocols, a planning horizon of no less than stewards of the environment, provide invaluable tools and 50 years, management component projects and actions a pathway toward the collective action needed to man- to achieve sustainability, and integration of land use de- age groundwater resources sustainably. Community en- cisions. Management component projects and actions to gagement is an important social tool and can be a driving be considered in management plans include conserva- force for fostering trust, acceptance, and support for the tion, water reuse, stormwater capture, managed aquifer management actions and costs, and ultimate compliance recharge and demand reduction. Recycled water and storm- to adhere to the actions implemented. . . . Community water should be put to beneficial use and developed as engagement should include encouraging local leadership resources. Water markets and water trades and transfers in key roles to nurture sound decisions and promote com- should also be tools employed in sustainable groundwa- pliance with needed actions. ter management. Management institutions will need to identify and engage these varied interests and determine how their in- 5. Managed aquifer recharge should be greatly increased globally volvement will be integrated into the decision-making, Managed aquifer recharge (mar) is defined as the in- coordination, and implementation processes necessary crease in groundwater recharge over natural infiltration to achieve groundwater sustainability. Further, the engage- processes as a result of interventions designed to enhance ment of the local community is an ongoing and never groundwater storage and quality. It is recognized as a ending process to achieve and maintain resource sus- key groundwater management component that is utilized tainability.2 widely for long-term sustainability. mar . . . helps to increase the storage and availability of water from aquifers, may improve the quality of groundwater through natural Conclusions subsurface treatment processes, and increases groundwater storage to supplement supplies during dry cycles The coming years will be decisive for moving toward a or severe and prolonged droughts. This makes it important new paradigm of sustainability for hydric resources that to promote mar application in management plans, pro- takes into account joint management of surface and vide appropriate incentives for local users to implement groundwater and recognizes reuse and recharge as fun- mar, and institute training of specialized personnel in this damental pillars of that. area. mar needs to be employed much more widely in order to replenish depleted aquifer systems and sustain groundwater resources in the future. mar should be implemented where economically viable in suitable aquifers that can accept a sufficient quantity and quality of water at an adequate recharge rate, within areas where groundwater use is being actively managed. 6. Effective groundwater management requires collaboration, robust stakeholder participation and community engagement  Notes 1 The Sustainable Groundwater Management Directives were produced by a large group of contributors. The authors of this article wish to particularly thank Roberto Ramírez de la Parra, Timothy Kevin Parker, Adriana Palma Nava, and Fernando González Cáñez for their efforts in developing and promoting these principles nationally and internationally. 2 http://www.ismar9.org/Doc/sustainabledirectives.pdf. [Translator’s Note.] 65