Chapter 7. Enforcement challenges and efforts to implement environmental flow requirements in Mexico1

This chapter discusses groundwater allocation challenges in Mexico. It documents how the government's attempts to exert greater control over groundwater pumping have been stymied by weak enforcement. It also documents efforts to secure water for environmental purposes via standards for environmental flows.


Over-allocation of groundwater resources has led to severe depletion

The allocation of groundwater in Mexico faces significant challenges due to resource scarcity and overdraft, widespread unauthorised use, as well as weak enforcement of national water legislation. On a national level, groundwater supplies 77% of urban water use, 50% of industrial and 33% of agricultural use (Cornett, 2014). In the state of Guanajuato, close to 100% of industrial and domestic water demand is met by groundwater (Foster et al., 2004). Over-allocation of the already scarce groundwater resource pool in Mexico has led to severe depletion. This has dire implications for both rural and urban water supply, as operational and replacement costs have increased significantly. Depletion also results in deterioring groundwater quality (e.g. increased salinity) and land subsidence (amounting to 2-3 cm per year in some areas) with damaging effects on public infrastructure and private property (Foster et al., 2004; Shah, 2014).

Abstraction bans and attempts to regularise users have failed to limit groundwater pumping

In the past, occasional pumping bans were used a key management tool to limit groundwater abstraction. Between 1948 and 1983, eleven pumping bans were issued in Guanajuato, and the National Water Commission (CONAGUA) attempted to enforce three periods of state-wide water well drilling ban during the 1990s. However, the bans were ineffective and the number of wells in Guanajuato has continued to expand rapidly since the 1960s (Foster et al., 2004; Shah, 2014; CONAGUA, 2016).

While groundwater entitlements formerly were tightly linked to land rights, the adoption of the 1992 National Water Act and subsequent amendments to national legislation brought about a reform of groundwater entitlements and regularisation of users. Today, all new and existing water users are legally required to be registered in the Public Register of Water Rights and to be assigned a quantitative water entitlement by CONAGUA. Users are obliged to install meters and report pumped quantities of groundwater to CONAGUA (CONAGUA, 2016; Shah, 2014).

The regularisation of groundwater users was supposed to help enforce drilling permit requirements and bans. However, the requirements regarding metering, reporting and groundwater entitlements are only minimally enforced, and unauthorised groundwater use remains widespread. Poor enforcement and lack of sanctioning is primarily due to lack of local operational resources and failure to mobilise user co-operation (Foster et al., 2004; Shah, 2014). Despite the existence of river basin organisations (RBOs), which are decentralised bodies of CONAGUA, co-ordination of water management across levels of government remains a challenge (OECD, 2013; CONAGUA, 2016). The enforcement of groundwater legislation is also hampered by politicians’ challenging trade-off between the control of groundwater abstraction and the desire to attract farmers’ votes (Shah, 2014).

Multi-stakeholder platforms have faced numerous challenges

Seeking ways to strengthen water management, the Mexican government established various multi-stakeholder platforms during the 1980s-90s, including river basin councils (RBCs). The RBCs are independent bodies, which are meant to enhance institutional co‐ordination as well as the relations between institutions and users of surface and groundwater (Millington, 2006). Twenty years after their creation, RBCs are still not fully operational, and their impact remains contested. In theory, the RBCs are supposed to allow for stakeholders’ independent management of water resources in each river basin, but in practice, they are primarily advisory bodies with very little power (Cornett, 2014, OECD, 2013).

The 1992 Water Act also gave impetus to the establishment of technical committees for groundwater (COTAS) in selected aquifers (OECD, 2013). COTAS are non-profit, civil associations created to foster self-regulation of groundwater withdrawal among users (Foster et al., 2004; OECD, 2013). In reality, actual user participation remains minimal and none of the 81 COTAS nation-wide has succeeded in implementing effective ways to reverse groundwater depletion (Molle and Wester, 2009; Cornett, 2014; CONAGUA, 2016). This is due to a lack of human resources, infrastructure and reliable information about well owners. The COTAS do not physically control the extraction infrastructure; thus they can not physically restrict withdrawals by well owners, and have to rely on their goodwill (Molle and Wester, 2009).

A national standard for environmental flows, which still needs to be implemented

Given the limited effects of the new entitlement regime and the multi-stakeholder platforms, Mexico has explored other means to sustain water resources. In 2000, CONAGUA adopted an official national standard requiring the establishment of methods for determination of annual average availability of national waters. NGOs and civil society constituted an important driver for subsequent work on the development of methods for determining environmental flows. Notably, the Alliance of the World Wildlife Fund for Nature and the Gonzalo Río Arronte Foundation reviewed different methodologies for determining environmental flows and explored how to reach an agreement with water users and adopt a legal act in this regard (Barrios-Ordóñez et al., 2015). Inspired by these efforts, the Program of the Environmental and Natural Resources Sector 2007-12 explicitly recommended that the government publish an official standard for the determination of environmental flows, which was done in 2012 (Cornett, 2014) The standard defines environmental flows as the flow rate or minimum volume needed in receiving bodies or the minimum flow of natural discharge of an aquifer in order to protect the environment and the ecological balance of system (OECD, 2015). The official standard is a means to regulate demand and supply for groundwater, and implies a legal recognition of the ecosystem as a legitimate user of water (Rodriguez, 2013).

Two key elements in the standard are the scientific principles of natural flow regime and biological condition gradient (Barrios, n.d., 2012). Natural flow regimes consist of five critical components that regulate ecological processes in river ecosystems. The alteration of these components can result in ecosystems and biological integrity degradation (Poff et al., 1997). The biological condition gradient refers to a conceptual, scientific framework for the interpretation of biological response to increasing effects of stressors on aquatic ecosystems (USEPA, 2016). Based on these two principles, the ultimate objective of the Mexican official standard is to match flow recommendations to available resources and capacity, ecosystem importance and conditions, and the anticipated extent for hydrologic alternation with water resources and infrastructure development (Conservation Gateway, n.d.). The official standard is not only concentrated on site or project level, but encompasses local procedures seeking to apply the Ecological Limits of Hydrologic Alteration (ELOHA) framework (Conservation Gateway, n.d.). The ELOHA framework requires stakeholders and decision-makers explicitly to evaluate “acceptable risk” as a balance between the perceived value of the ecological goals and the economic costs involved, taking into account the scientific uncertainties between ecological responses and flow alteration (OECD, 2015; Poff et al., 2011).

Lessons learned

The enforcement of groundwater legislation remains a challenge for Mexican authorities along with reforming perverse subsidies, such as Tarifa 9, a preferential tariff for electricity to pump groundwater for rural users, undermining policy coherence (OECD, 2013) (see Health Check #10, Part I). As a result, groundwater depletion is exacerbated and the resource pool remains over-exploited. The adoption of the 2012 standard for determination of environmental flows has the potential to help adapt groundwater allocation to sustainable levels of groundwater use. By proposing a variety of methodological approaches to environmental flow estimation, the standard allows for the adaptation of methods based on available input and resources (Barrios, n.d.). It also recognises the importance of not fixing a standard minimum environmental flow, but adjusting to different hydrologies across the country (Barrios-Ordóñez et al., 2015).

The standard for determining environmental flows can help to define an abstraction limit (a cap) reflecting sustainable use (see Health Check #4, Part I). It can also be used to identify and protect water reserves. Mexico’s National Water Reserves Programme (NWRP), was developed in parallel with the 2012 standard, and seeks to identify potential water reserves where natural flows can be secured. The NWRP has facilitated the examination of 732 basins nation-wide, classifying all watersheds into four categories, based on their water balance and ecological importance. This helps policy-makers obtain a better understanding of the availability of groundwater resources and ensuring environmental uses are secured (see Health Checks #3 and #5, Part I).

The successful implementation of environmental flows as part of the groundwater allocation regime is hampered by a number of obstacles, including elements in the National Water Act. Ambiguity and lack of coherence in national legislation weaken the application of the standard. For example, the legislation gives stakeholders at river basin level the freedom to prioritise water for agriculture and livestock above environmental flows. Legislation also fails to determine whether “environmental use” is one out of many purposes for which water can be granted in an entitlement, or a preliminary restriction of the volume of water available for all entitlements. Moreover, the lack of control of abstraction and the large number of groundwater users complicates the enforcement of environmental flows. As long as the effectiveness of multi-stakeholder platforms for water management remains limited, it will be challenging to reach consensus among users about the importance of restricting groundwater abstraction volumes. Legal reforms may be necessary in order to allow for further harmonisation of the National Water Act and the national standard for environmental flows.


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Barrios-Ordóñez, J. et al. (2015), “Programa nacional de reservas de agua en México: experiencias de caudal ecológico y la asignación de agua al ambiente” [National program of water reserves in Mexico: experiences of ecological flow and the allocation of water to the environment], Inter-American Development Bank, (accessed 20 May 2016).

Conservation Gateway (n.d.), “ELOHA case study Mexico”, Practices/Freshwater/EnvironmentalFlows/MethodsandTools/ELOHA/Pages/ELOHA-case-study-Mexico.aspx (accessed 16 July 2016).

CONAGUA (2016), Personal correspondence with Member of the International Cooperation Department, Daniel Rivera, Deputy Manager of Geohydrological Information Systems, Domingo Silva, and Manager of Groundwater, Ruben Chavez Guillen.

Cornett, V. (2014), “Limitations and opportunities for environmental flow implementation under current Mexican law and policy”, Water Law Review, Vol. 17/10, pp. 223-266.

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United States Environmental Protection Agency (USEPA) (2016), “A practitioner’s guide to the biological condition gradient: a framework to describe incremental change in aquatic ecosystems”, EPA-842-R-16-001, USEPA, Washington, DC,


← 1. This document and any map included herein are without prejudice to the status of or sovereignty over any territory, to the delimitation of international frontiers and boundaries and to the name of any territory, city or area.