ArticlePDF Available

Abstract and Figures

Sharing scientific data and information is often cited within academic literature as an initial step of water cooperation, but the transfer of research findings into policy and practice is often slow and inconsistent. Certain attributes—including salience, credibility, and legitimacy of scientific information; iterative information production; and sociocultural factors—may influence how easily scientific information can be used in management and policymaking. However, transnationality usually complicates these sorts of interactions. Accordingly, we argue that the production of scientific information and transboundary water cooperation build upon each other bidirectionally, each informing and enhancing the other. We employ a case-study analysis of the Transboundary Aquifer Assessment Program (TAAP), a binational collaborative effort for scientific assessment of aquifers shared between Mexico and the United States. Here, information sharing was possible only by first completing a formal, jointly agreed-upon cooperative framework in 2009. This framework resulted in a collaborative science production process, suggesting that the relationship between sharing data and information and transboundary groundwater governance is iterative and self-reinforcing. In keeping with the publication of the TAAP’s first binational scientific report in 2016, we demonstrate the bidirectional relationship between science production and water governance in the TAAP and explore remaining challenges after scientific assessment.
Content may be subject to copyright.
water
Article
Science and Binational Cooperation: Bidirectionality in the
Transboundary Aquifer Assessment Program in the
Arizona-Sonora Border Region
Jacob D. Petersen-Perlman 1, 2, * , Tamee R. Albrecht 3,4, Elia M. Tapia-Villaseñor 5, Robert G. Varady 3
and Sharon B. Megdal 2


Citation: Petersen-Perlman, J.D.;
Albrecht, T.R.; Tapia-Villaseñor, E.M.;
Varady, R.G.; Megdal, S.B. Science
and Binational Cooperation:
Bidirectionality in the Transboundary
Aquifer Assessment Program in the
Arizona-Sonora Border Region. Water
2021,13, 2364. https://doi.org/
10.3390/w13172364
Academic Editor: Pankaj Kumar
Received: 24 June 2021
Accepted: 21 August 2021
Published: 28 August 2021
Publisher’s Note: MDPI stays neutral
with regard to jurisdictional claims in
published maps and institutional affil-
iations.
Copyright: © 2021 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
1Department of Geography, Planning, & Environment, East Carolina University, Greenville, NC 27858, USA
2Water Resources Research Center, The University of Arizona, Tucson, AZ 85719, USA;
smegdal@email.arizona.edu
3Udall Center for Studies in Public Policy, The University of Arizona, Tucson, AZ 85719, USA;
talbrecht@email.arizona.edu (T.R.A.); rvarady@arizona.edu (R.G.V.)
4School of Geography, Development & Environment, University of Arizona, Tucson, AZ 85721, USA
5Departamento de Geología, Universidad de Sonora, Hermosillo 83000, Mexico; elia.tapia@unison.mx
*Correspondence: petersenperlmanj19@ecu.edu
Abstract:
Sharing scientific data and information is often cited within academic literature as an
initial step of water cooperation, but the transfer of research findings into policy and practice is often
slow and inconsistent. Certain attributes—including salience, credibility, and legitimacy of scientific
information; iterative information production; and sociocultural factors—may influence how easily
scientific information can be used in management and policymaking. However, transnationality
usually complicates these sorts of interactions. Accordingly, we argue that the production of scien-
tific information and transboundary water cooperation build upon each other bidirectionally, each
informing and enhancing the other. We employ a case-study analysis of the Transboundary Aquifer
Assessment Program (TAAP), a binational collaborative effort for scientific assessment of aquifers
shared between Mexico and the United States. Here, information sharing was possible only by first
completing a formal, jointly agreed-upon cooperative framework in 2009. This framework resulted
in a collaborative science production process, suggesting that the relationship between sharing data
and information and transboundary groundwater governance is iterative and self-reinforcing. In
keeping with the publication of the TAAP’s first binational scientific report in 2016, we demonstrate
the bidirectional relationship between science production and water governance in the TAAP and
explore remaining challenges after scientific assessment.
Keywords:
transboundary waters; groundwater; US–Mexico; water governance; science produc-
tion; bidirectionality
1. Introduction
The arid to semiarid region of the southwestern United States (US) and northwestern
Mexico is water-short in most of its geographical reach. Climate-change predictions
indicate rising temperatures and increased variability in precipitation patterns, leading
to water supply reductions by the middle of the 21st century [
1
3
]. This hydrological
variability affects groundwater basins; the southwestern US is likely to experience declines
in groundwater recharge, including in basins such as the San Pedro [
4
] and Santa Cruz [
5
,
6
].
Mexico and the US share four river basins (Tijuana, Colorado, Yaqui, and Rio Grande/
Rio Bravo). The two that are by far the largest, the Colorado and Rio Grande/Rio Bravo
basins, encompass almost the entirety of the border region. Additionally, 36 aquifers have
been identified along the Mexico–US border; 16 of these can be categorized as transbound-
ary [
7
]. Yet, while surface-water agreements govern and manage the binational Tijuana,
Water 2021,13, 2364. https://doi.org/10.3390/w13172364 https://www.mdpi.com/journal/water
Water 2021,13, 2364 2 of 19
Colorado, and Rio Grande/Rio Bravo river basins, there exists no formal agreement on
management of any of the transboundary aquifers.
The absence of binational/multinational transboundary institutions governing in-
ternationally shared groundwater is typical among almost all transboundary aquifers.
Globally, for the almost 600 identified aquifers crossing international boundaries [
8
], only a
handful of formal agreements over transboundary groundwater exist [
9
,
10
], even in loca-
tions that exhibit high levels of cooperation regarding other issues. Developing a shared
understanding is a prerequisite to joint management of a resource, most especially an un-
seen one. The US and Mexico have cooperated scientifically—though not managerially—to
assess four of their shared aquifers: the San Pedro and Santa Cruz, shared between Sonora
(Mexico) and Arizona (US), and the Mesilla–Conejos Medanos and Hueco Bolson, shared
among three subfederal entities: the Mexican state of Chihuahua, and the US states of New
Mexico and Texas (Figure 1).
Water 2021, 13, 2364 3 of 20
Figure 1. TAAP’s aquifers of focus on the Mexico–US border.
2. Literature Review
While the science–policy interface has been addressed in water management gener-
ally (e.g., [16,17]) and transboundary water management specifically (e.g., [18]), little has
been written describing which elements of water governance need to be present for copro-
duction of knowledge to occur in a transboundary setting (Armitage et al. [19] being a
notable exception). Acknowledging that our selection of key principles for the science–
policy interface in transboundary groundwater governance is not exhaustive, we review
frequently identified principles for analyzing groundwater governance and the science–
policy interface in the following paragraphs.
2.1. Principles for Analyzing Groundwater Governance
Though governmental entities are more likely to be cooperative than conflictive over
shared waters [20], there exist certain factors that make it easier—or more difficult—for
cooperation to occur. Among the barriers to transboundary cooperation are spatial and
social distance [21–24]; limitations in institutional capacity, financial resources, participa-
tion capacity, and data availability [25]; layering and asymmetries of governance struc-
tures [26] and intrajurisdictional integration within countries [27,28]; incompatible gov-
ernance cultures and mandates; and mistrust and/or lack of leadership [25]. Here, social
distance refers to disparities in cultural, ethnic, religious, linguistic, political, administra-
tive, legal, and traditional ways of managing and governing water resources. These and
other potential asymmetries complicate transboundary resources management. Drivers
for transboundary cooperation include leadership, personal relationships, contacts, the
existence of binational (or multinational) institutions, and functioning networks [25].
When initiating cooperation on international waters, the chances of such cooperation
being successful increase when autonomies of each party are respected, basinwide networks
Figure 1. TAAP’s aquifers of focus on the Mexico–US border.
Transboundary water resources—whether above or below the surface—span a bor-
der and are shared. Here we highlight that the information, interpretation, science, and
actions that are needed to manage those resources flow both ways across the border in
question. Our aim is to show that the relationship between science production and ground-
water governance is bidirectional, with institutions in both countries exerting influence on
the outcomes.
The paper seeks to analyze the case study using process tracing ([
11
]; see, e.g.,
[12,13]
).
We argue that analyzing the two-way flow of science production and cooperative gov-
ernance (e.g., [
14
]) has yet to be adequately explored in transboundary groundwater
governance literature. Specifically, we look at how these processes enhance each other
in the Transboundary Aquifer Assessment Program (TAAP) aquifers of focus (Figure 1)
shared between Arizona and Sonora—the Santa Cruz and San Pedro aquifers.
Water 2021,13, 2364 3 of 19
First, looking at one direction of the flow, we examine how national and binational poli-
cies and cooperative actions, spearheaded by university and government agency research
partnerships on both sides of the border, led to advancements in scientific knowledge. The
most notable of those advancements was the completion of the first-ever binational scien-
tific aquifer assessments, prepared and released simultaneously in English and Spanish by
the (US–Mexico) International Boundary and Water Commission (IBWC).The IBWC/CILA
(Comisión Internacional de Límites y Aguas; the Mexican name of the commission) is
the binational organization whose mission is “to provide binational solutions to issues
that arise during the application of US–Mexico treaties regarding boundary demarcation,
national ownership of waters, sanitation, water quality, and flood control in the border
region” [15].
Then, viewing the other direction, we discuss how data and information resulting
from assessments may contribute to future decision-making for shared groundwater in the
border region.
In the following sections, we explore principles of water governance and, specifically,
which factors enhance cooperation in groundwater governance. As part of the process,
we also examine the role of science in informing policymaking. Next, we use the outlined
principles of water governance to analyze how elements of the science–policy interface
relate to groundwater governance in the case of the TAAP in Arizona and Sonora.
2. Literature Review
While the science–policy interface has been addressed in water management generally
(e.g., [
16
,
17
]) and transboundary water management specifically (e.g., [
18
]), little has been
written describing which elements of water governance need to be present for coproduction
of knowledge to occur in a transboundary setting (Armitage et al. [
19
] being a notable
exception). Acknowledging that our selection of key principles for the science–policy
interface in transboundary groundwater governance is not exhaustive, we review fre-
quently identified principles for analyzing groundwater governance and the science–policy
interface in the following paragraphs.
2.1. Principles for Analyzing Groundwater Governance
Though governmental entities are more likely to be cooperative than conflictive over
shared waters [
20
], there exist certain factors that make it easier—or more difficult—for
cooperation to occur. Among the barriers to transboundary cooperation are spatial and so-
cial distance [
21
24
]; limitations in institutional capacity, financial resources, participation
capacity, and data availability [
25
]; layering and asymmetries of governance structures [
26
]
and intrajurisdictional integration within countries [
27
,
28
]; incompatible governance cul-
tures and mandates; and mistrust and/or lack of leadership [
25
]. Here, social distance refers
to disparities in cultural, ethnic, religious, linguistic, political, administrative, legal, and
traditional ways of managing and governing water resources. These and other potential
asymmetries complicate transboundary resources management. Drivers for transboundary
cooperation include leadership, personal relationships, contacts, the existence of binational
(or multinational) institutions, and functioning networks [25].
When initiating cooperation on international waters, the chances of such cooperation
being successful increase when autonomies of each party are respected, basinwide networks
of scientists are established, diverse groups of stakeholders are consulted, and perhaps
above all, all parties establish and maintain trust [
29
]. Such cooperation encourages solving
common problems and cultivates interdependence and mutual understanding [30].
Narrowing our focus to transboundary groundwater, scholars have recognized the
underdeveloped and/or fragmented structures for resolving critical problems in ground-
water governance [
10
,
31
34
]. Here, we define groundwater governance as “the overarching
framework of groundwater use laws, regulations, and customs, as well as the processes of
engaging the public sector, the private sector, and civil society ([
35
]; p. 678]). Cooperation
is a key element in transboundary aquifer governance. Enabling factors include: existing le-
Water 2021,13, 2364 4 of 19
gal mechanisms, functioning regional institutions, funding mechanisms, high institutional
capacity, previous water cooperation, scientific research, and strong political will [36].
Several articles have identified elements, or “pillars,” of surface water and ground-
water governance (e.g., [
10
,
37
41
]). Regarding groundwater, principles for management,
planning, and assessment can be summarized as follows: stakeholder engagement and in-
clusion,proper assessment and data for analysis,management and planning for groundwater use,
integrated water management, and protection of groundwater resources [10,38,39].
The reviews of groundwater governance principles and enabling factors presented
here feature certain commonalities, including stakeholder engagement, management and
planning, integrated water management, protecting groundwater resources, functioning
institutional presence and capacity, history of water cooperation, funding, and political
will. Other common factors are data sharing and scientific cooperation. Even low levels of
scientific research can motivate some degree of cooperation [
36
], as that research can lead
to increased transparency [42].
Complications associated with transboundary aquifers have been recognized for many
years by scholars and intergovernmental organizations (e.g., [
43
,
44
]). Although few in
number, formal international groundwater agreements vary in their legal nature, scope,
status, content, duration, and driving motivation, and of course, degree of successful
implementation [
45
]. This suggests that approaches to international groundwater problems
are often site-specific and ad hoc in nature [
21
]. The few existing international groundwater
agreements all contain some mechanism for data collection and/or exchange, and most also
provide an institutional framework [
45
]. One of the most prominent such agreements ad-
dresses the GuaraníAquifer in South America. The countries had to overcome asymmetries
in political power and water governance structures (e.g., level of centralization) [
46
]. De-
spite the original promise of the accord, implementation has been a challenging process [
47
].
Jordan and Saudi Arabia also signed and ratified a bilateral (though not fully operational)
agreement on the Disi Aquifer in 2015 [
48
] after exploitation from both countries, including
withdrawals from a Jordanian pipeline project [49].
2.2. Analyzing the Science–Policy Interface in Transboundary Groundwater Governance
The bidirectional relationship between data-cum-information exchange and ground-
water governance is a clear example of the science–policy interface. We define this interface
to be how policy actors and scientists interact with each other through processes such as ex-
changing and joint constructing knowledge [
50
]. This building of place-based knowledge of
groundwater resources is a key step toward effective management and governance [
51
]. In
transboundary contexts, scientific assessment is a needed initial step to determine whether
and the extent to which individual aquifers are cross-border physical systems (see [
8
,
52
]).
Assessment can also help to catalog existing data sources and identify what data gaps exist.
Such lacunae are common for transboundary aquifers because availability of and access to
groundwater data are especially constrained [
53
], of uneven quality and reliability, and
sometimes the result of disparate measurement systems and protocols [22].
Long-term planning for sustainable groundwater management also requires both char-
acterization and ongoing monitoring due to the complexity and everchanging conditions
of aquifer systems and inherent scientific uncertainty in groundwater evaluation. Man-
agement practices need to account for hydrogeological characteristics of transboundary
aquifers via such strategies as pollution prevention, integrated land and water management,
and context-specific approaches [39,5456].
Certain attributes—such as salience, credibility, and legitimacy of scientific data
and information—may determine how easily scientific information can be utilized in
management and decision-making [
57
]. Salience (the relevance of information to decision-
makers and/or the public; [
57
]) increases when the questions asked are relevant to the
actors involved; it can be achieved through cooperative development of project goals
via two-way communication [
58
,
59
]. Building trust and accountability via long-term
relationships also bolsters salience, along with credibility (the creation of information that
Water 2021,13, 2364 5 of 19
is believable, trusted, and authoritative; [
57
]) and legitimacy of the process of knowledge
production (the perception of how fair the knowledge production is, whether it includes
different perspectives, and appropriate values and concerns; [
57
,
60
]). Involving actors
perceived as experts in the task at hand tends to enhance credibility. However, if experts do
not represent multiple points of view, or if the information is not produced via a transparent
process, the data may not be perceived as fully legitimate. Legitimacy can be increased
when scientific data are generated via cooperative, inclusive efforts, using mutually agreed-
upon protocols. Conversely, lack of consensus on the instruments and methods used
for data collection can impede cross-border cooperation [
61
]. Collaborative knowledge
production and institutionalized science–policy processes that engage stakeholders—either
via a cross-border organization or established network of stakeholders—can bolster the
legitimacy of decision-making processes and knowledge generated in transboundary water
contexts [19].
These science–policy processes may not necessarily yield deliberate progress toward
some final state, but they do offer a developmental path from an initial state [
62
]. They
may require iteration, building on previous practices, and learning from past successes
and failures. Iterative processes are essential to positive science–policy interface outcomes,
since capacity, trust building, and adaptability require multiple iterations [
63
65
]. Multiple
iterations may also be necessary when new data or understanding is obtained [62,66].
In some cases, cross-border knowledge generation can provide a foundation for or
promote further cooperation, such as formal agreements. Of the existing international
agreements on shared groundwater, most were initiated by knowledge-generation efforts
and/or from funding and assistance from international organizations [
45
]. Cooperation can
be promoted via joint collection of high-quality data—thereby reducing the potential for
data to be contested [
67
]. Joint monitoring, data collection, and data sharing are recognized
as beginning steps within the cooperative process [
68
]. Joint studies of the GuaraníAquifer
System [
47
,
69
], the Nubian Sandstone Aquifer [
70
], and the Iullemeden Aquifer [
69
] are
examples of this.
Yet in other cases, having prior cooperation or specific agreements in place can also
help lead to improved scientific studies. Joint scientific studies may require a foundation of
cooperative relations that could include transboundary institutional capacity, a framework
for cooperation, or merely the presence of trust and prior working relationships. These
studies on transboundary waters are often used to alleviate unidentified gaps in knowledge,
missing information, data incompatibility, variation in quality control of data, and lack
of scientific understandings [
71
]. Armitage et al. [
19
] describe the importance of setting
the “conditions for collaboration” early on in transboundary science–policy processes
by engaging relevant stakeholders, building relationships and bolstering trust. In both
the Danube and the Orange–Senqu basins, for example, establishment of transboundary
institutions—river basin organizations—made it possible to conduct cohesive basinwide
water quality studies via collaborative studies involving all basin states in knowledge
production [
19
]. Similarly, the US–Mexico agreement on the release of an environmental
pulse flow in the Colorado River led to many new scientific discoveries [72].
When science is produced via collaborative processes that engage multiple parties, the
information produced is more likely to be accepted by the participating countries. Science–
policy processes for transboundary groundwater do not evolve the same way each time—
the process is nuanced and involves give-and-take between progress toward scientific
investigation and information gathering on the one hand, and political cooperation and
agreements enabling people and organizations to work together on the other. Examples
of how this critical bidirectional relationship between science and policy manifests in
transboundary water governance is demonstrated in Figure 2.
Using the principles of good governance and role of science in decision-making
outlined above, we turn now to analyze groundwater governance and processes of science
production in one illustrative case: the implementation of the TAAP in Sonora and Arizona.
Water 2021,13, 2364 6 of 19
Water 2021, 13, 2364 6 of 20
knowledge production [19]. Similarly, the US–Mexico agreement on the release of an en-
vironmental pulse flow in the Colorado River led to many new scientific discoveries [72].
When science is produced via collaborative processes that engage multiple parties,
the information produced is more likely to be accepted by the participating countries. Sci-
ence–policy processes for transboundary groundwater do not evolve the same way each
time—the process is nuanced and involves give-and-take between progress toward scien-
tific investigation and information gathering on the one hand, and political cooperation
and agreements enabling people and organizations to work together on the other. Exam-
ples of how this critical bidirectional relationship between science and policy manifests in
transboundary water governance is demonstrated in Figure 2.
Figure 2. Bidirectionality of science production and transboundary water governance. Case study
examples aside from the TAAP are from [69].
Figure 2.
Bidirectionality of science production and transboundary water governance. Case study
examples aside from the TAAP are from [69].
3. Materials and Methods
This paper employs a case-study method to investigate the relationship between
science production and groundwater governance in the US–Mexico border region. Based
on the results of our literature review above, we hypothesize the following:
Hypothesis 1 (H1).
Science contributes to and influences transboundary groundwater governance
by informing management with a transboundary scientific understanding on both sides of the
international border.
Hypothesis 2 (H2).
Transboundary groundwater governance, through policies, agreements, and
other cooperative efforts, contributes to and influences the course of scientific inquiry by expanding
Water 2021,13, 2364 7 of 19
cooperative scientific networks across the border, including communities of practice. This in turn helps to
generate new scientific knowledge that likely would not be possible without governmental cooperation.
To test these hypotheses, we employ both process tracing and interviews. First, we
analyze elements that have been identified as enabling factors for good groundwater
governance, as synthesized from the literature: stakeholder engagement and inclusion,
management and planning for groundwater use, integrated water management, protecting
groundwater resources, institutional presence and capacity, history of water cooperation,
funding, and political will. “Good governance” suggests normative characteristics of being
efficient, inclusive, and sustainable. Next, we use key features of scientific information that
promote its ease of use in policymaking—salience, credibility, legitimacy [
57
], and iterative
knowledge production [
63
,
64
]—to evaluate the bidirectional relationship of science and
policy. Finally, we gathered data by conducting 20 interviews of government officials and
scientists on both sides of the border (see Supplementary Materials, Table S1), participant
observation, and by compiling secondary sources from binational technical meetings,
conferences, and stakeholder meetings that took place during the 2010–2019 period.
We asked two sets of interview questions: one for scientists (Table S2), and one for
government officials (Table S3). Questions for scientists focused on whether and how
transboundary groundwater governance contributes to science by engaging relevant stake-
holders, building relationships, and bolstering trust, thereby leading to scientific discov-
eries. Questions for government officials queried whether and how science (specifically
groundwater assessment) contributes to groundwater governance.
4. Results
The adjacent transboundary Santa Cruz and San Pedro aquifers are in southeastern
Arizona and northeastern Sonora (Figure 3). Both aquifers support significant populations
and economic activities such as mining, agriculture, ranching, tourism, and manufacturing.
These aquifers have also seen rapid population growth in recent years [73,74].
Water 2021, 13, 2364 8 of 20
Figure 3. The Santa Cruz and San Pedro aquifers.
4.1. Water Management and Governance on Both Sides of the Border
Different modes and institutions for water governance between Mexico and the US
complicate bilateral cooperation and assessment by making the transfer of information
and reaching consensus more challenging. Water management and governance in Mex-
ico’s nonborder waters tend to be more centralized than in the US [26]. The authority to
regulate surface water and groundwater in Mexico resides with Comisión Nacional del
Agua (CONAGUA), the national water authority. CONAGUA is responsible for all activ-
ities concerning use, management, and protection of national water. At the state and sub-
state levels of government in Mexico, water management is more limited compared to the
US; CEA Sonora (Comisión Estatal del Agua Sonora, Sonora’s state water commission)
assists municipalities in providing water and sanitation services and administers water
supply-related programs, and certain municipalities run their own water and wastewater
utilities [75].
Water management and governance in the US generally occur at the state and/or sub-
state level. The federal government has built projects for flood control, transportation, hy-
dropower dams, and large-scale water diversions [76] and has set water quality goals
through measures such as the 1972 US Clean Water Act and the 1974 US Safe Drinking
Water Act. States have authority over implementation of standards, practices, and rules
for water use [77]. In Arizona, state law considers groundwater and surface water as dis-
tinct water bodies and are regulated as such. While surface water rights in Arizona are
regulated under a prior-appropriation system (“first in time, first in right”), groundwater
use is based on beneficial use (e.g., agricultural, industrial, or residential). Groundwater
regulations vary across the state. Several regions of the state, including the US portion of
the Santa Cruz Aquifer, are designated Active Management Areas (AMAs), where
groundwater use is subject to regulations that are meant to be enforced by the Arizona
Department of Water Resources [78,79]. As Figure 2 shows, the US portion of the bi-
national San Pedro Aquifer is not part of an AMA.
Figure 3. The Santa Cruz and San Pedro aquifers.
4.1. Water Management and Governance on Both Sides of the Border
Different modes and institutions for water governance between Mexico and the US
complicate bilateral cooperation and assessment by making the transfer of information and
Water 2021,13, 2364 8 of 19
reaching consensus more challenging. Water management and governance in Mexico’s
nonborder waters tend to be more centralized than in the US [
26
]. The authority to regulate
surface water and groundwater in Mexico resides with Comisión Nacional del Agua
(CONAGUA), the national water authority. CONAGUA is responsible for all activities
concerning use, management, and protection of national water. At the state and substate
levels of government in Mexico, water management is more limited compared to the
US; CEA Sonora (Comisión Estatal del Agua Sonora, Sonora’s state water commission)
assists municipalities in providing water and sanitation services and administers water
supply-related programs, and certain municipalities run their own water and wastewater
utilities [75].
Water management and governance in the US generally occur at the state and/or
substate level. The federal government has built projects for flood control, transportation,
hydropower dams, and large-scale water diversions [
76
] and has set water quality goals
through measures such as the 1972 US Clean Water Act and the 1974 US Safe Drinking
Water Act. States have authority over implementation of standards, practices, and rules for
water use [
77
]. In Arizona, state law considers groundwater and surface water as distinct
water bodies and are regulated as such. While surface water rights in Arizona are regulated
under a prior-appropriation system (“first in time, first in right”), groundwater use is based
on beneficial use (e.g., agricultural, industrial, or residential). Groundwater regulations vary
across the state. Several regions of the state, including the US portion of the Santa Cruz
Aquifer, are designated Active Management Areas (AMAs), where groundwater use is
subject to regulations that are meant to be enforced by the Arizona Department of Water
Resources [
78
,
79
]. As Figure 2shows, the US portion of the binational San Pedro Aquifer is
not part of an AMA.
4.2. Binational Water Management
The 1944 treaty, “Utilization of Waters of the Colorado and Tijuana Rivers and of
the Rio Grande,” gives the IBWC authority to make rules through adopting minutes
(interpretations and clarifications) to the treaty. The IBWC has some authority in water
shared between Mexico and the US to ensure compliance with the 1944 treaty, manage joint
infrastructure, maintain hydrologic monitoring stations, and communicate information
across the border [
80
]. This is due in part because Mexico’s policy requires that all border
groundwater (and surface water) issues be handled through the commission [
81
]. The
IBWC comprises two sections, with one section in Mexico (CILA) and one in the US.
In the past century, Mexico and the US have expanded transboundary surface wa-
ter governance capacity, moved towards inclusion of non-nation-state actors, increased
ecological considerations, and have signed agreements related to surface water—most
notably the 1944 treaty [
82
]. There exists no agreement over the management of shared
groundwater aside from Minute 242, which addresses groundwater pumping near the
US–Mexico border near San Luis, Mexico [
83
]. Minute 242 authorized the IBWC to begin
discussions on a binational groundwater agreement [
80
], but little progress has been made
to date. Issues surrounding water rights on both sides of the border, including those of
private parties and concessionaires, remain unresolved [
84
]. There have also been notable
disputes between both countries regarding water management, including over the issue of
salinity of the Colorado River as it enters Mexico [85].
4.3. Establishment of the TAAP
Both the US and Mexico have recognized that greater scientific understanding of their
shared groundwater resources would be mutually beneficial, particularly within a region
where groundwater is a primary component of the water balance and where populations
are growing. The two countries signed the La Paz Agreement in 1983, which formally
committed the US and Mexico to annual meetings between ministries and reviewing
border environmental concerns. The agreement did not include any specific solutions
or environmental protections but does provide a mechanism to do so in the future if
Water 2021,13, 2364 9 of 19
desired [
86
]. The US Congress authorized Public Law 109-448 in late 2006, whose formal
name is the United States–Mexico Transboundary Aquifer Assessment Act (TAAA) [
87
].
Though the TAAA signaled US interest in participating in binational studies, Mexican
concurrence was needed to proceed with a binational program and identification of aquifers
of focus.
From 2007 to 2009, Mexico and the US began the engagement and negotiation process
that resulted in approval by the IBWC of the “Joint Report of the Principal Engineers
Regarding the Joint Cooperative Process United States–Mexico for the Transboundary
Aquifer Assessment Program” (Joint Report [
88
]). The Joint Report guides the binational
study of four transboundary aquifers: the San Pedro, Santa Cruz, Mesilla, and Hueco
Bolson. The key word for the cooperation between the two countries is “assessment”—
the Joint Report specifies that information that comes from cooperation is “solely for the
purpose of expanding knowledge of the aquifers and should not be used by one country to
require that the other country modify its water management and use” ([
88
], p. 3). Further,
the Joint Report also states that activities should be beneficial to both countries and cannot
limit what each country can do independently within its boundaries.
4.4. Summary of Governance Principles Present
Some of the governance principles for management, planning, and assessment iden-
tified in the literature review are present in the TAAP case study. These elements have
allowed for successful completion of scientific assessments but have not allowed for a
transboundary management regime to manifest at this point.
Stakeholder engagement was one of the keys to the project’s success; a broad set of
stakeholders and key actors was involved in early efforts that determined the scope of
assessment. Stakeholder engagement efforts during the project have included establishing
modes of communication through webpages, factsheets, and briefings. The project was
most likely aided by the long history of binational stakeholder engagement in the region
(see [89]).
There are no binding binational management and planning efforts regarding the TAAP
aquifers. Aside from Minute 242, which does not involve any of the TAAP aquifers, there
were no binding existing legal mechanisms dealing specifically with groundwater prior
to the establishment of the TAAP. Elsewhere, the Municipal Water and Sanitation Board
of the City of Juárez (Chihuahua, Mexico) and the El Paso Water Utilities Public Service
Board (El Paso, TX, USA) signed a legally unenforceable and unofficial memorandum of
understanding that calls for cooperation over and information exchange for the Hueco
Bolson Aquifer in 1999 [90,91].
In addition to the absence of binding binational management and planning efforts,
the two countries also have not engaged in binational integrated water management. There
have been no binational efforts toward integrated water management elements such as
managed aquifer recharge or collaborative modeling (though both countries have expressed
interest in building binational models of the aquifers). Neither have there been any specific
binational efforts toward protecting groundwater resources in terms of IBWC Minutes on
water quality or quantity for the TAAP aquifers, though Minutes 261, 276, and 294 do
designate impaired water quality resulting from border sanitation as an issue that should
be addressed.
Though the IBWC had not previously had a specific focus on groundwater, it was
undoubtedly a critical functioning regional institution for the function of the TAAP. The
IBWC, along with CONAGUA, were key players for the development of the Joint Report.
The IBWC’s expertise in managing treaty obligations (previous water cooperation) and Mexi-
can policies regarding transboundary waters made the binational organization central in
formalizing the cooperative framework [22].
Funding was provided by each country, but there were times when the timing of fund-
ing availability was asynchronous between the two countries. This resulted in differences
between countries in the amount and type of work at a given time.
Water 2021,13, 2364 10 of 19
Political will was evident throughout the TAAP process. The approval of the TAAP
had to go through multiple official channels, including the 2006 US TAAA and the IBWC.
Stakeholder involvement was also significant in developing the assessment’s parame-
ters. Because the parties have limited their efforts to assessment, there has been no
test of the political will associated with addressing the institutionally complex matter
of joint management.
4.5. Summary of Attributes for Information to Be Used in Decision-Making
Salience of scientific information increases when the questions asked are relevant to
actors involved. While binational priorities were developed jointly, some studies focusing
on the TAAP aquifers were not binational as each country can conduct work within its
own borders without needing to consult the other, in accordance with the Joint Report
(e.g., [
5
]). Binational forums resulted in the development of strategic plans for the two
Arizona–Sonora aquifers, outlining priorities and tasks, with annual tactical plans allow
for more adaptive research to realities relating to funding, resources, personnel, and new
progress [26].
The TAAP team attended and participated at conferences to communicate and ex-
change information with others in the scientific community. Team members have also
disseminated journal articles, theses, and reports to enhance credibility. The Sonora–Arizona
effort has yielded two reports: the Binational Study of the Transboundary San Pedro Aquifer,
published in 2016, and the Binational Study of the Transboundary Santa Cruz Aquifer, which is
undergoing peer review. Both studies address their attention to physical characteristics of
the aquifers—the geology, climate, hydrology, landcover, and soils—and integrate these
data across the entire geographic extent of the aquifer, evaluating it for the first time as
a single physical system. Besides the work published by Pool and Dickinson [
92
] on the
Sierra Vista Subwatershed and Sonoran portions of the Upper San Pedro Basin, binational
maps were not common for the Transboundary San Pedro Aquifer. The same is true for
the Transboundary Santa Cruz Aquifer, where only a few sources present harmonized
binational cartography [
93
,
94
]. The San Pedro study produced 42 aquiferwide geographic
information system (GIS) layers containing data about the aquifer, which served as the
basis for the development of over 34 binational maps that describe multiple aspects of
the study area [
95
]. Each of the two reports represents a one-of-a-kind type of assessment.
The studies analyze and harmonize information from two different countries. Analyz-
ing and harmonizing information required overcoming language barriers, institutional
asymmetries, mapping and measurement preferences, and review processes.
Identifying each country’s team members was one of the initial challenges of the TAAP.
In Mexico, for example, some of the members were required by governmental policy to
go through CILA for this task, as Mexico requires that all border water issues be handled
through CILA. Universidad de Sonora and CONAGUA carried out the studies. US funding
was divided among the federally authorized Water Resources Research Institutes in Texas,
New Mexico, and Arizona, and the US Geological Survey Water Science centers in those
three states, as required by the TAAA. Selection of team members who were bilingual also
eased the process of communication.
4.6. Interview Results
Officials interviewed from both countries agreed that the information generated from
the reports could be used for recommendations and regulations (though were less cer-
tain about whether the information would help regulations), and an informal or formal
binational groundwater organization. Interviewees said that the results are potentially
useful for, e.g., confirming past conceptual understandings on the other side of the border,
some adjudication decisions in Arizona, and providing information for other forms of
decision-making. Figure 4presents a summary of interviewees’ scores for salience, en-
gaging stakeholders, bolstering trust and building relationships (interviews of scientists),
and salience, credibility, and legitimacy (interviews of government officials). The TAAP’s
Water 2021,13, 2364 11 of 19
collaborative and iterative process of scientific assessment helped produce information
that is more salient, credible and legitimate—regarding the transboundary aquifer—than
could have been produced by either country alone (Table 1).
Water 2021, 13, 2364 12 of 20
Scientists Government Officials
Figure 4. Summary of interview scores.
Table 1. Science production and relevant attributes of science outputs in the TAAP.
Features of Science Production Relevant Attributes of
Science Outputs
Binational development of research aims and focus areas
through Binational Technical Group meetings Legitimacy, salience, iteration
Investment of funding or in-kind investments from both
countries Legitimacy
Involvement of binational experts in knowledge produc-
tion Credibility, iteration
Stakeholder involvement in planning Salience, legitimacy, iteration
Integration and harmonization of data from both nations Salience, iteration
Bilingual reporting of results (Binational Studies of the
San Pedro and Santa Cruz Aquifers) Legitimacy
No binational work contributing toward the assessment happened until the 2009
Joint Report. During this time, the Arizona–Sonora team engaged in team- and trust-
building. Participation in field trips helped build trust and a shared history among team
members. We define trust as an expectation or belief that one group can rely on another’s
3.8
3.1
4.6
-
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Global US MX
Salience
3.9
3.6
4.3
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Global US MX
Salience
4.1
3.7
4.6
-
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Global US MX
Engaging relevant stakeholders
4.2 4.1
4.6
-
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Global US MX
Legitimacy
3.1
2.6
3.7
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Global US MX
Building relationships/bolstering trust
4.1
3.7
4.6
-
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Global US MX
Credibility
Figure 4. Summary of interview scores.
Table 1. Science production and relevant attributes of science outputs in the TAAP.
Features of Science Production Relevant Attributes of
Science Outputs
Binational development of research aims and focus areas
through Binational Technical Group meetings Legitimacy, salience, iteration
Investment of funding or in-kind investments from
both countries Legitimacy
Involvement of binational experts in knowledge production
Credibility, iteration
Stakeholder involvement in planning Salience, legitimacy, iteration
Integration and harmonization of data from both nations Salience, iteration
Bilingual reporting of results (Binational Studies of the San
Pedro and Santa Cruz Aquifers) Legitimacy
Water 2021,13, 2364 12 of 19
Regular and continuous communication and cooperation among the TAAP stakehold-
ers also bolstered the legitimacy and acceptability of scientific information produced. The
science produced by the Arizona–Sonora TAAP effort achieved legitimacy at the national
level, gaining official approval by the governments of both the US and Mexico. Inclusion
of social scientists in project design helped address social and institutional aspects of
cross-border cooperation, which are critical to the production of legitimate knowledge.
No binational work contributing toward the assessment happened until the 2009 Joint
Report. During this time, the Arizona–Sonora team engaged in team- and trust-building.
Participation in field trips helped build trust and a shared history among team members.
We define trust as an expectation or belief that one group can rely on another’s actions and
word and/or that the group has good intentions toward others [
96
]. During the period of
the study, the Binational Technical Group meetings established by the Joint Report also
helped to build trust: “Through the collaborative work we have learned about the capacity
and experience of the other researchers. It is not the same to know a person through what
he or she has published as it is to work together with them,” one TAAP scientist said. The
cooperative process was also aided by previous cooperative work conducted by Mexican
and US geologists over the last 50 years. The multiple iterations of communication were
essential for the process to continue and the work to be completed.
Both groups of Mexican officials and scientists interviewed for this article gave higher
scores compared to their US counterparts in all six categories portrayed in Table 1. These
higher scores could imply that Mexico perceives more benefits from the transboundary
aquifer assessment process through sharing previous studies, data, and technical resources.
The program also allows for arguably greater opportunities for Mexican researchers to
expand their research networks compared to their US counterparts.
5. Bidirectionality and the Science–Policy Interface
Key elements of “good governance” and of collaborative scientific assessment pro-
cesses both contributed to fruitful binational cooperation over assessment of these aquifers.
We show the bidirectional interaction between groundwater governance and science pro-
duction in Figure 5.
Water 2021, 13, 2364 13 of 20
actions and word and/or that the group has good intentions toward others [96]. During
the period of the study, the Binational Technical Group meetings established by the Joint
Report also helped to build trust: “Through the collaborative work we have learned about
the capacity and experience of the other researchers. It is not the same to know a person
through what he or she has published as it is to work together with them,” one TAAP
scientist said. The cooperative process was also aided by previous cooperative work con-
ducted by Mexican and US geologists over the last 50 years. The multiple iterations of com-
munication were essential for the process to continue and the work to be completed.
Both groups of Mexican officials and scientists interviewed for this article gave higher
scores compared to their US counterparts in all six categories portrayed in Table 1. These
higher scores could imply that Mexico perceives more benefits from the transboundary
aquifer assessment process through sharing previous studies, data, and technical re-
sources. The program also allows for arguably greater opportunities for Mexican research-
ers to expand their research networks compared to their US counterparts.
5. Bidirectionality and the Science–Policy Interface
Key elements of “good governance” and of collaborative scientific assessment pro-
cesses both contributed to fruitful binational cooperation over assessment of these aqui-
fers. We show the bidirectional interaction between groundwater governance and science
production in Figure 5.
Figure 5. The path to bidirectionality/binationality in the TAAP. Governance elements are represented by blue circles;
science elements are represented by green hexagons. Figure by authors.
The TAAP engaged in science production with joint research projects through the
binational studies. Transboundary cooperation was established through trust and rela-
tionship building among actors. One TAAP scientist interviewed said, “The binational
relations have been strengthened in many levels- [on the] local, formal, academic and re-
search level, [we’ve engaged in] collaboration and [generated] trust, long term projects,
Figure 5.
The path to bidirectionality/binationality in the TAAP. Governance elements are repre-
sented by blue circles; science elements are represented by green hexagons. Figure by authors.
Water 2021,13, 2364 13 of 19
The TAAP engaged in science production with joint research projects through the bina-
tional studies. Transboundary cooperation was established through trust and relationship
building among actors. One TAAP scientist interviewed said, “The binational relations
have been strengthened in many levels- [on the] local, formal, academic and research level,
[we’ve engaged in] collaboration and [generated] trust, long term projects, medium term,
joint collaboration.” Trust and relationship-building was aided by the already-established
relationship between governments through the IBWC and other governmental avenues
of cooperation. This was achieved through formal agreements in data and information
sharing through the 1944 agreement and subsequent minutes. The establishment of a frame-
work for a joint or collaborative binational study through the 2009 Joint Report helped to
build a formal cooperation channel that was sheltered by the IBWC. Previous collaboration
efforts lacked a coordinating body, Binational Technical Groups, and Binational Technical
Advisory Committees. This led to ambiguities within studies and barriers associated to
information distribution and availability.
In the context of US–Mexico transboundary groundwater, our view is that science
can palpably contribute to US–Mexico groundwater governance (Hypothesis 1) in two
key ways: (1) by informing management on each side of the border with a transboundary
scientific understanding, and (2) by expanding binational cooperative networks—including
communities of practice—on local, state, and national levels. These foundational coopera-
tive elements allowed for a collaborative process of science production that goes beyond
merely sharing information. From a ”science-to-governance” perspective, collaborative sci-
entific assessment of shared aquifers can help to inform water management decisions at the
local (e.g., water rights adjudication in Arizona) and national (e.g., determining availability
of groundwater in Mexico) levels, provides a shared knowledge-base and strengthened
trust among participants. Multiple scientists said that the TAAP has helped scientists in
learning to collaborate and promoted making contacts on the other side of the border. All
scientists involved with the TAAP said that they have made new contacts thanks to the
program: “Through this program we had the fortune to meet several researchers in the field
and know what they do and be familiar with their work,” one TAAP scientist said. Another
TAAP scientist said, “Because of TAAP, now I know who to go to [if I had a question about
groundwater across the border].”
From a “governance-to-science” perspective (Hypothesis 2), the previous cooperation
over water between Mexico and the US through the 1944 treaty and their subsequent
minutes undoubtedly facilitated the establishment of the binational assessment process.
Interviewed scientists said that the previous treaty and minutes helped to strengthen
communication between countries.
The political will of stakeholders and policy makers played a significant role for the
assessments. Funding provided by each country showed investment in the assessment’s
outcome. The investment of time that it took for the parties to agree upon the 2009 Joint
Report was arguably worthwhile, as it allowed them to create a document that struck
a balance between independence—where both countries conduct and fund their own
research activities on their side of the border—and coordination, including communication
of information through sharing data publicly, e.g., through the publication of the assess-
ments. Parties were able to harmonize information and overcome barriers, differences, and
preferences through the Binational Technical Group and Binational Technical Advisory
Committee meetings. The 2009 Joint Report guided how cross-border scientific efforts were
carried out—e.g., via binational teams—which helped reduce the possibility that either
nation would object to the knowledge produced. While one scientist pointed out that the
2009 Joint Report allowed for the assessments to happen, another scientist mentioned that
it was an obstacle for them due to the level of formality associated with the protocol. The
process for sharing data required multiple iterations. Both parties were initially cautious
about sharing information. The data sharing process became more efficient as the studies
progressed. Over time, scientists interviewed said that participation in multiple, face-to-
face meetings built trust and relationships between team members. The meetings led to
Water 2021,13, 2364 14 of 19
collaborative science production by helping to resolve issues including jointly determining
the delineation of the study area, data needs, and data integration and compatibility: “In
both of those watersheds [San Pedro and Santa Cruz], there is a significant amount of
data—making the results meaningful to stakeholders needs to be part of the package,”
one US government official said. However, we should note that the results from scientists
involved with the TAAP program may exhibit a more favorable view of the products
resulting from the TAAP.
The IBWC was necessary as a coordinating body for the assessments. Its institutional
capacity, (manifested through its authority in ensuring compliance with the 1944 treaty),
its management of joint infrastructure and maintenance of hydrologic monitoring stations,
its protocols for data exchange, its contribution of funding, and its role in transboundary
communication, all contributed to helping the assessment process. With suitable adap-
tation for context, this effort could be replicable for other areas of scientific cooperation
between Mexico and the US, and perhaps for other transborder-resource studies [
97
]. In the
TAAP, steps taken on transboundary groundwater governance and production of scientific
information built upon each other. This bidirectionality contributed to partially harmonize
asymmetries in institutional frameworks between Mexico and the US, particularly because
of the central role of the IBWC in its collection of binational data and coordination of the
joint studies.
As an example of how governance elements and science production build upon
each other bidirectionally, the TAAP process began with a joint decision regarding which
aquifers would be assessed first. This consensus-based decision-making helped formulate
project aims that are salient for stakeholders on both sides of the border. Datasets produced
are comprehensive and harmonized across the border, in turn, allowing for better access to
decision-makers and improved legitimacy of the information. Overall, the collaborative
process enhanced legitimacy of the information produced through transparency and bina-
tional engagement. The resultant cross-border network of scientists and other stakeholders
can be leveraged to help guide further efforts toward addressing shared goals. For instance,
one TAAP scientist referenced how the TAAP has allowed for advancements in mapping
geologic units that were beyond the scope of the original assessments.
There is no agreement to extend cooperation beyond scientific investigation and
collaboration. However, if a more formal binational management regime were to come
to pass (which appears unlikely according to interviewees), the availability of reliable
scientific information would be an initial step [
69
,
70
,
97
99
]. From the outset, building trust
and mutual respect have been important components of the assessment’s realization. Both
countries would need to continue to build trust and navigate jurisdictional overlaps for a
development of a binational management agreement, among other things.
It is possible that assessments such as the ones achieved by the TAAP will help to
determine the severity of existing challenges and promote joint problem-framing and
agenda-setting. Reaching a mutual understanding on aquifer and groundwater conditions
is arguably a necessary (though not sufficient) condition for collaborative management.
Such a strategy would help direct resources more efficiently to address the problems. That
said, assessment can only go so far in leading to resolution of the groundwater manage-
ment issues in the Santa Cruz and San Pedro aquifers. Rules, regulations, monitoring,
enforcement of those rules and regulations, and perhaps most importantly, public accep-
tance, political will, and financial commitment are needed to resolve management issues.
It appears likely that scientific assessments alone will need other factors to generate the
political will necessary to create a binational management regime in this case or elsewhere.
There may be some potential for more localized cooperation between subnational
jurisdictions within these aquifers. There has also already been informal, local cooperation
in sharing water between the cities of Nogales, Arizona, and Nogales, Sonora, in times of
serious drought in the Santa Cruz Aquifer [
91
] or during other specific problems such as
fires [100].
Water 2021,13, 2364 15 of 19
6. Conclusions
This article argues, using the case study of the TAAP Sonora–Arizona assessments as
an example, that transboundary groundwater governance and the production of scientific
information evolve in reciprocal synchronicity—cooperation can enhance science produc-
tion, and science can lead to advancements in policy. Both are needed for transboundary
groundwater governance, as they are in nontransboundary situations. Certain elements of
governance need to be present for scientific assessments to occur—particularly via collabo-
rative efforts—and for the knowledge gathered through the efforts of the assessments to be
potentially usable for future policy- and decision-making. In the case of the TAAP, the estab-
lishment of trust, the cooperative framework, and the history of cooperation between the
two countries through formal agreements were particularly important to successful assess-
ments. These components helped the binational team overcome challenges of integrating
different standards and methods for reporting, peer review, language, measurement units,
and technical and financial capacities, among others. While salience, credibility, legitimacy,
and iterations of assessment and information-sharing can certainly aid further cooperation,
it has yet to be seen whether the assessments will aid transboundary water governance
between the two countries. Because of this, it should be noted that the case study is one
example of bidirectionality, which may not be present in all cases. More evidence is needed
from other cases to prove our argument.
More work lies ahead for policymakers to continue collaborative efforts after the
completion of the assessments. A few questions about how momentum can be sustained,
how the results of the assessments are being used, identifying the sources for financing, de-
termining if political will exists to continue collaboration and progress to governance, and
continuing the trust-building process, are yet to be answered. The politically charged issues
surrounding water rights between the two countries also are yet to be solved. Despite the
questions listed above, the TAAP case has several elements that enable groundwater col-
laboration. It is also consistent with some of the principles included in other groundwater
management agreements around the world [99].
The TAAP case suggests that the relationship between data-cum-information-sharing
and transboundary water governance is iterative and self-reinforcing. All discrete gover-
nance and information elements are part of a larger cooperative process. This process could
help yield an eventual binational agreement (or agreements) such as those for the Genevois,
Guaraní, Iullemeden, and Nubian aquifer systems. Since decision-making ultimately is a
political process, we believe that, as elsewhere, science is a necessary condition for forging
international groundwater agreements. Along with science, political will, stakeholder
engagement, and adequate incentives to cooperate are critical factors for initiating and
sustaining transboundary cooperation.
Supplementary Materials:
The following are available online at https://www.mdpi.com/article/10
.3390/w13172364/s1, Table S1: Data on interviewees, Table S2: Interview questions for scientists,
Table S3: Interview questions for government officials.
Author Contributions:
J.D.P.-P. and T.R.A. conceived the article; J.D.P.-P., T.R.A. and E.M.T.-V.
designed and performed the experiments; J.D.P.-P., T.R.A. and E.M.T.-V. analyzed the data; J.D.P.-P.,
T.R.A., E.M.T.-V., R.G.V. and S.B.M. wrote the article. All authors have read and agreed to the
published version of the manuscript.
Funding:
This work was partially funded by the US Geological Survey (funding authorized by
P.L. 109–448) Award Number G17AC00439 for the Transboundary Aquifer Assessment Program.
Institutional Review Board Statement:
This project has been reviewed and approved by an IRB
Chair or designee from East Carolina University (protocol UMCIRB 21-000087).
Informed Consent Statement:
Informed consent was obtained from all subjects involved in the study.
Data Availability Statement:
Data sharing is not applicable to this study. The information shared
during the interview process is confidential and cannot be shared with the public.
Water 2021,13, 2364 16 of 19
Acknowledgments:
The authors thank interviewees for their time and their participation. Thanks
also to Jaclyn Best for her assistance in data processing and Javier Tadeo Villaseñor for translation
and transcription of interviews conducted in Spanish. The authors are grateful for support from the
Morris K. Udall and Stewart L. Udall Foundation in Tucson, Arizona; and from Lloyd’s Register
Foundation in the U.K. Thank you to the reviewers for their helpful comments.
Conflicts of Interest:
J.D.P.-P., E.M.T.-V. and S.B.M. were partially funded by the Transboundary
Aquifer Assessment Program.
References
1.
Pagán, B.R.; Ashfaq, M.; Rastogi, D.; Kendall, D.R.; Kao, S.-C.; Naz, B.S.; Mei, R.; Pal, J.S. Extreme Hydrological Changes in the
Southwestern US Drive Reductions in Water Supply to Southern California by Mid Century. Environ. Res. Lett.
2016
,11, 094026.
[CrossRef]
2.
Romero-Lankao, P.; Smith, J.B.; Davidson, D.J.; Diffenbaugh, N.S.; Kinney, P.L.; Kirshen, P.; Kovacs, P.; Villers Ruiz, L. North
America. In Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part B: Regional Aspects. Contribution of Working
Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change; Barros, V.R., Field, C.B., Dokken, D.J.,
Mastrandrea, M.D.,
Mach, K.J., Eren Billir, T., Chatterjee, M., Ebie, K.L., Otsuki Estrada, Y., Genova, R.C., et al., Eds.; Cambridge
University Press: Cambridge, UK; New York, NY, USA, 2014; pp. 1439–1498. ISBN 978-1-107-05816-3.
3.
Wilder, M.; Garfin, G.; Ganster, P.; Eakin, H.; Romero-Lankao, P.; Lara-Valencia, F.; Cortez-Lara, A.A.; Mumme, S.P.; Neri, C.;
Muñoz-Arriola, F.; et al. Climate change and U.S.-Mexico border communities. In Assessment of Climate Change in the Southwest
United States: A Report Prepared for the National Climate Assessment; Garfin, G., Jardine, A., Merideth, R., Black, M., LeRoy, S., Eds.;
Island Press: Washington, DC, USA, 2013; pp. 340–384. ISBN 978-1-61091-446-8.
4.
Meixner, T.; Manning, A.H.; Stonestrom, D.A.; Allen, D.M.; Ajamie, H.; Blasch, K.W.; Brookfield, A.E.; Castro, C.L.; Clark, J.F.;
Gochis, D.J.; et al. Implications of projected climate change for groundwater recharge in the western United States. J. Hydrol.
2016,534, 124–138. [CrossRef]
5.
Shamir, E.; Megdal, S.B.; Carillo, C.; Castro, C.L.; Chang, H.-I.; Chief, K.; Corkhill, F.E.; Eden, S.; Georgakakos, K.P.;
Nelson, K.M.; et al.
Climate change and water resources management in the Upper Santa Cruz River, Arizona. J. Hydrol.
2015
,
521, 18–33. [CrossRef]
6.
Shamir, E.; Tapia-Villaseñor, E.M.; Cruz-Ayala, M.B.; Megdal, S.B. A review of climate change impacts on the USA-Mexico
transboundary Santa Cruz River Basin. Water 2021,13, 1390. [CrossRef]
7.
Sanchez, R.; Eckstein, G. Aquifers shared between Mexico and the United States: Management perspectives and their transbound-
ary nature. Groundw 2017,55, 495–505. [CrossRef]
8.
International Groundwater Resources Assessment Centre (IGRAC). Transboundary Aquifers of the World. Special Edition for the
7th World Water Forum. 2015. Available online: https://www.un-igrac.org/resource/transboundary-aquifers-world-map-2015
(accessed on 3 August 2021).
9.
Burchi, S. Legal frameworks for the governance of international transboundary aquifers: Pre- and post-ISARM experience. J.
Hydrol. Reg. Stud. 2018,20, 15–20. [CrossRef]
10.
Megdal, S.B.; Petersen-Perlman, J.D. Groundwater governance and assessment in a transboundary setting. In Lake Governance,
1st ed.; Grover, V., Krantsberg, G., Eds.; CRC Press: Boca Raton, FL, USA, 2018; pp. 38–60. ISBN 9781138633759.
11. Vanhala, L. Process tracing in the study of environmental politics. Glob. Environ. Politics 2017,17, 88–105. [CrossRef]
12.
Kashwan, P. Forest policy, institutions, and REDD+ in India, Tanzania, and Mexico. Glob. Environ. Politics
2015
,15, 95–117.
[CrossRef]
13.
Kauffman, C.; Mann, P. Scaling up Buen Vivir: Globalizing local environmental governance from Ecuador. Glob. Environ. Politics
2014,14, 40–58.
14.
Milman, A.; MacDonald, A. Focus on interactions between science-policy in groundwater systems. Environ. Res. Lett.
2020
,
15, 090201. [CrossRef]
15.
International Boundary and Water Commission-Comision Internacional de Limites y Agua (IBWC). Welcome. Available online:
http://www.ibwc.gov/home.html (accessed on 3 August 2021).
16.
Dunn, G.; Brown, R.R.; Bos, J.J.; Bakker, K. The role of science-policy interface in sustainable urban water transitions: Lessons
from Rotterdam. Environ. Sci. Policy 2017,73, 71–79. [CrossRef]
17.
Dunn, G.; Bos, J.J.; Brown, R.R. Mediating the science-policy interface: Insights from the urban water sector in Melbourne,
Australia. Environ. Sci. Policy 2018,82, 143–150. [CrossRef]
18.
Bukowski, J. A “new water culture” on the Iberian Peninsula? Evaluating epistemic community impact on water resources
management policy. Environ. Plan. C 2016,35, 239–264. [CrossRef]
19.
Armitage, D.; de Loë, R.C.; Morris, M.; Edwards, T.W.D.; Gerlak, A.K.; Hall, R.I.; Huitema, D.; Ison, R.; Livingstone, D.;
MacDonald, G.; et al. Science-policy processes for transboundary water governance. Ambio 2015,44, 353–366. [CrossRef]
20. Wolf, A.T.; Yoffe, S.B.; Giordano, M. International waters: Identifying basins at risk. Water Policy 2003,5, 29–60. [CrossRef]
21.
Blomquist, W.; Ingram, H.M. Boundaries seen and unseen: Resolving transboundary groundwater problems. Water Int.
2003
,28,
162–169. [CrossRef]
Water 2021,13, 2364 17 of 19
22.
Callegary, J.B.; Megdal, S.B.; Tapia-Villaseñor, E.M.; Minjárez-Sosa, I.; Petersen-Perlman, J.D.; Monreal, R.; Gray, F.;
Grijalva Noriega, F.
Findings and lessons learned from the assessment of the Mexico-United States transboundary San Pedro and
Santa Cruz aquifers: The utility of social science in applied hydrologic research. J. Hydrol. Reg. Stud.
2018
,20, 60–73. [CrossRef]
23. Udall, S.L.; Varady, R.G. Environmental conflict and the world’s new international borders. Transbound Resour Rep. 1994,7, 5–6.
24.
Varady, R.G.; Morehouse, B.J. Moving borders from the periphery to the center: River basins, political boundaries, and water
management policy. In Water: Science, Policy, and Management; Lawford, R., Fort, D., Hartmann, H., Eden, S., Eds.; American
Geophysical Union: Washington, DC, USA, 2003; pp. 143–160. ISBN 978-0875903200.
25.
Norman, E.; Bakker, K. Drivers and Barriers of Cooperation in Transboundary Water Governance: A Case Study of
Western Canada and the United States; Report to the Walter and Duncan Gordon Foundation. 2005. Available online:
https://watergovernance.ca/2017/07/15/drivers-and-barriers-of-cooperation-in-transboundary-water-governance-a-case-
study-of-western-canada-and-the-united-states/ (accessed on 4 August 2021).
26.
Megdal, S.B.; Scott, C.A. The importance of institutional asymmetries to the development of binational aquifer assessment
programs: The Arizona-Sonora experience. Water 2011,3, 949–963. [CrossRef]
27.
Albrecht, T.R.; Varady, R.G.; Zuniga-Teran, A.A.; Gerlak, A.K.; De Grenade, R.R.; Lutz-Ley, A.; Martín, F.; Megdal, S.B.;
Meza, F.;
Ocampo Melgar, D.; et al. Unraveling transboundary water security in the arid Americas. Water Int.
2018
,43, 1075–1113.
[CrossRef]
28.
Cohen, A.; Norman, E.S. Renegotiating the Columbia River Treaty: Transboundary governance and indigenous rights. Glob.
Environ. Politics 2018,18, 4–24. [CrossRef]
29.
Petersen-Perlman, J.D.; Wolf, A.T. Getting to the first handshake: Enhancing security by initiating cooperation in transboundary
river basins. J. Am. Water Resour. Assoc. 2015,51, 1688–1707. [CrossRef]
30.
Ide, T.; Detges, A. International water cooperation and environmental peacemaking. Glob. Environ. Politics
2018
,18, 63–84.
[CrossRef]
31.
De Chaisemartin, M.; Varady, R.G.; Megdal, S.B.; Conti, K.I.; van der Gun, J.; Merla, A.; Nijsten, G.-J.; Scheibler, F. Addressing the
groundwater governance challenge. In Freshwater Governance for the 21st Century; Karar, E., Ed.; Springer International Publishing:
Cham, Switzerland, 2017; pp. 205–227. ISBN 978-3-319-43350-9.
32. Giordano, M. Global groundwater? Issues and solutions. Ann. Rev. Environ. Resour. 2009,34, 153–178. [CrossRef]
33.
Megdal, S.B. Invisible water: The importance of good groundwater governance and management. NPJ Clean. Water
2018
,1, 15.
[CrossRef]
34.
Theesfeld, I. Institutional challenges for national groundwater governance: Policies and issues. Groundwater
2010
,48, 131–142.
[CrossRef]
35.
Megdal, S.B.; Gerlak, A.K.; Varady, R.G.; Huang, L.-Y. Groundwater governance in the United States: Common priorities and
challenges. Groundwater 2015,53, 677–684. [CrossRef]
36.
Conti, K.I. Cooperation over transboundary aquifers: Lessons learned from 10 years of experience. In Free Flow: Reaching Water
Security through Cooperation; Griffiths, J., Lambert, R., Eds.; UNESCO: Paris, France, 2013; pp. 40–44. ISBN 978-92-3-104256-0.
37.
Biswas, A.K.; Tortajada, C. Future water governance: Problems and perspectives. In Improving Water Policy and Governance;
Tortajada, C., Biswas, A., Eds.; Routledge: New York, NY, USA, 2011; pp. 1–13. ISBN 978-0415606288.
38.
Akhmouch, A.; Clavreul, D. Assessing and monitoring groundwater governance. In Advances in Groundwater Governance, Vilholth,
K.G., López-Gunn, E., Conti, K., Garrido, A., van der Gun, J., Eds.; Taylor & Francis Group: London, UK, 2018; pp. 247–265.
ISBN 978-1138029804.
39.
Albrecht, T.R.; Varady, R.G.; Zuniga-Teran, A.A.; Gerlak, A.K.; Staddon, C. Governing a shared hidden resource: A review of
governance mechanisms for transboundary groundwater security. Water Secur. 2017,2, 43–56. [CrossRef]
40.
Kiparsky, M.; Milman, A.; Owen, D.; Fisher, A.T. The importance of institutional design for distributed local-level governance of
groundwater: The case of California’s Sustainable Groundwater Management Act. Water 2017,9, 755. [CrossRef]
41.
Varady, R.G.; Zuniga-Teran, A.A.; Gerlak, A.K.; Megdal, S.B. Modes and approaches of groundwater governance: A survey of
lessons learned from selected cases across the globe. Water 2016,8, 417. [CrossRef]
42.
Ciplet, D.; Adams, K.M.; Weikmans, R.; Timmons Roberts, J. The transformative capability of transparency in global environmental
governance. Glob. Environ. Politics 2018,18, 130–150. [CrossRef]
43.
Puri, S.; Appelgren, B.; Arnold, G.; Aureli, A.; Burchi, S.; Burke, J.; Margat, J.; Pallas, P. Internationally Shared (Transboundary)
Aquifer Resources Management: Their Significance and Sustainable Management; Non Serial Document, SC-2001/WS/40; Puri, S., Ed.;
UNESCO: Paris, France, 2001; pp. 1–71.
44.
Puri, S.; Aureli, A. Transboundary aquifers: A global program to assess, evaluate, and develop policy. Groundwater
2005
,43,
661–668. [CrossRef]
45.
Movilla Pateiro, L. Ad hoc legal mechanisms governing transboundary aquifers: Current status and future prospects. Water Int.
2016,41, 851–865. [CrossRef]
46.
Hussein, H. The Guarani Aquifer System, highly present but not high profile: A hydropolitical analysis of transboundary
groundwater governance. Environ. Sci. Policy 2018,83, 54–62. [CrossRef]
47.
Sindico, F.; Hirata, R.; Manganelli, A. The Guarani Aquifer System: From a beacon of hope to a question mark in the governance
of transboundary aquifers. J. Hydrol. Reg. Stud. 2018,20, 49–59. [CrossRef]
Water 2021,13, 2364 18 of 19
48.
Hussein, H.; Menga, F.; Greco, F. Monitoring transboundary water cooperation in SDG 6.5. 2: How a critical hydropolitics
approach can spot inequitable outcomes. Sustainability 2018,10, 3640. [CrossRef]
49. Ferragina, E.; Greco, F. The Disi project: An internal/external analysis. Water Int. 2008,33, 451–463. [CrossRef]
50. Van den Hove, S. A rationale for science-policy interfaces. Futures 2007,39, 807–826. [CrossRef]
51.
Ostrom, E. Governing the Commons: The Evolution of Institutions for Collective Action; Cambridge University Press: Cambridge, UK,
1990; ISBN 0-521-40599-8.
52.
Margat, J.; van der Gun, J. Groundwater around the World: A Geographic Synopsis; CRC Press: Boca Raton, FL, USA, 2013;
ISBN 9780367576509.
53.
Linton, J.; Brooks, D.B. Governance of transboundary aquifers: New challenges and new opportunities. Water Int.
2011
,36,
606–618. [CrossRef]
54.
Foster, S.; Ait-Kadi, M. Integrated Water Resources Management (IWRM): How does groundwater fit in? Hydrogeol. J.
2012
,20,
415–418. [CrossRef]
55.
Giordano, M.; Shah, T. From IWRM back to integrated water resources management. Int. J. Water Resour. Dev.
2014
,30, 364–376.
[CrossRef]
56.
Varady, R.G.; van Weert, F.; Megdal, S.B.; Gerlak, A.K.; Abdalla Iskandar, C.; House-Peters, L. GEF-FAO Groundwater Governance
Project: A Global Framework for Country Action. Thematic Paper No. 5: Groundwater Policy and Governance; With Major Editing
by Dellinger McGovern, E. 2013. Available online: https://www.researchgate.net/publication/281824294_Groundwater_
Governance_A_Global_Framework_for_Country_Action (accessed on 4 August 2021).
57.
Cash, D.; Clark, W.C.; Alcock, F.; Dickson, N.M.; Eckley, N.; Jäger, J. Salience, credibility, legitimacy and boundaries: Linking
research, assessment and decision making. In KSG Working Papers Series RWP02-046; Harvard University: Cambridge, MA, USA,
2002; p. 25. [CrossRef]
58.
Lemos, M.C.; Kirchhoff, C.J.; Ramprasad, V. Narrowing the climate information usability gap. Nat. Clim. Chang.
2012
,2, 789–794.
[CrossRef]
59.
Reed, M.S.; Stringer, L.C.; Fazey, I.; Evely, A.C.; Kruijsen, J.H.J. Five principles for the practice of knowledge exchange in
environmental management. J. Environ. Manag. 2014,146, 337–345. [CrossRef]
60.
Kirchhoff, C.J.; Lemos, M.C.; Dessai, S. Actionable knowledge for environmental decision making: Broadening the usability of
climate science. Ann. Rev. Environ. Resour. 2013,38, 393–414. [CrossRef]
61.
Milman, A.; Ray, I. Interpreting the unknown: Uncertainty and the management of transboundary groundwater. Water Int.
2011
,
36, 631–645. [CrossRef]
62.
Elshall, A.S.; Tsai, F.T.-C. Constructive epistemic modeling of groundwater flow with geological structure and boundary condition
uncertainty under Bayesian paradigm. J. Hydrol. 2014,517, 105–119. [CrossRef]
63.
Dilling, L.; Lemos, M.C. Creating usable science: Opportunities and constraints for climate knowledge use and their Implications
for science policy. Glob. Environ. Chang. 2011,21, 680–689. [CrossRef]
64.
Sarkki, S.; Tinch, R.; Niemelä, J.; Heink, U.; Waylen, K.; Timaeus, J.; Young, J.; Watt, A.; Neßhöver, C.; van den Hove, S. Adding
‘iterativity’ to the credibility, relevance, legitimacy: A novel scheme to highlight dynamic aspects of science-policy interfaces.
Environ. Sci. Policy 2015,54, 505–512. [CrossRef]
65.
Sugg, Z.P.; Varady, R.G.; Gerlak, A.K.; de Grenade, R. Transboundary groundwater governance in the Guarani Aquifer System:
Reflections from a survey of global and regional experts. Water Int. 2015,40, 377–400. [CrossRef]
66.
Voss, C.I.; Soliman, S.M. The transboundary non-renewable Nubian Aquifer System of Chad, Egypt, Libya, and Sudan: Classical
groundwater questions and parsimonious hydrogeologic analysis and modeling. Hydrogeol. J. 2014,22, 441–468. [CrossRef]
67.
Kahane, Y. The Turonian-Cenomanian Aquifer. In Management of Shared Groundwater Resources: The Israeli-Palestinian Case with an
International Perspective; Feitelson, E., Haddad, M., Eds.; Springer: New York, NY, USA, 2001; pp. 83–106. ISBN 978-0-7923-7254-7.
68.
Feitelson, E.; Haddad, M. Identification of Joint Management Structures for Shared Aquifers: A Cooperative Palestinian-Israeli Effort;
World Bank Publications: Washington, DC, USA, 1998; Volume 415, ISBN 0-8213-4307-6.
69.
Conti, K.I. Factors Enabling Transboundary Aquifer Cooperation: A Global Analysis; UN-IGRAC: Delft, The Netherlands, 2014; p. 108.
70.
Grossman, M. Cooperation on Africa’s international waterbodies: Information needs and the role of information-sharing. In
Transboundary Water Management in Africa: Challenges for Development Cooperation; Scheumann, W., Neubert, S., Eds.; Deutsches
Institut für Entwicklungspolitick: Bonn, Germany, 2006; pp. 173–236. ISBN 3-88985-326-9.
71.
Milman, A.; Gerlak, A.K.; Albrecht, T.R.; Colosimo, M.; Conca, K.; Kittikhoun, A.; Kovács, P.; Moy, R.; Schmeier, S.;
Wentling, K.; et al.
Addressing knowledge gaps for transboundary environmental governance. Glob. Environ. Chang.
2020
,
64, 102162. [CrossRef]
72.
Kendy, E.; Flessa, K.W.; Schlatter, K.J.; de la Parra, C.A.; Hinojosa Huerta, O.M.; Carrillo-Guerrero, Y.K.; Guillen, E. Leveraging
environmental flows to reform water management policy: Lessons learned from the 2014 Colorado River Delta pulse flow. Ecol.
Eng. 2017,106, 683–694. [CrossRef]
73.
Prichard, A.H.; Scott, C.A. Interbasin water transfers at the US–Mexico border city of Nogales, Sonora: Implications for aquifers
and water security. Int. J. Water Resour. Dev. 2014,30, 135–151. [CrossRef]
74.
Varady, R.G.; Moote, M.A.; Merideth, R. Water allocation options for the Upper San Pedro basin: Assessing the social and
institutional landscape. Nat. Resour. J. 2000,40, 223–235.
Water 2021,13, 2364 19 of 19
75.
Milman, A.; Scott, C.A. Beneath the surface: Intranational institutions and management of the United States—Mexico trans-
boundary Santa Cruz Aquifer. Environ. Plan. C Politics Space 2010,28, 528–551. [CrossRef]
76.
McNabb, D.E. Water resource management comes of age. In Water Resource Management; Palgrave MacMillan: Cham, Switzerland,
2017; pp. 163–185. ISBN 978-3-319-54816-6.
77. Abrams, R.H. Legal convergence of East and West in contemporary American water law. Environ. Law 2012,42, 65–92.
78. Megdal, S.B. Arizona groundwater management. Water Rep. 2012,104, 9–15.
79.
Arizona Town Hall. Keeping Arizona’s Water Glass Gull. 2015. Available online: https://aztownhall.org/resources/Documents/
107%20Keeping%20Arizona\T1\textquoterights%20Water%20Glass%20Full%20FINAL%20Report%20web.pdf (accessed on
21 June 2021).
80.
Mumme, S.P. Innovation and reform in transboundary resource management: A critical look at the International Boundary and
Water Commission, United States and Mexico. Nat. Resour. J. 1993,33, 93–120.
81.
Mumme, S.P. Minute 242 and beyond: Challenges and opportunities for managing transboundary groundwater on the Mexico-U.S.
border. Nat. Resour. J. 2000,40, 341–378.
82.
Wilder, M.O.; Varady, R.G.; Gerlak, A.K.; Mumme, S.P.; Flessa, K.W.; Zuniga-Teran, A.A.; Scott, C.A.; Pineda Pablos, N.;
Megdal, S.B
. Hydrodiplomacy and adaptive governance at the U.S.-Mexico border: 75 years of tradition and innovation in
transboundary water management. Environ. Sci. Policy 2020,112, 189–202. [CrossRef]
83.
IBWC. Minute 242: Permanent and Definitive Solution to the International Problem of Salinity of the Colorado River. 1973.
Available online: https://www.usbr.gov/lc/region/pao/pdfiles/min242.pdf (accessed on 6 August 2021).
84.
Hatch Kuri, G. A joint management of transboundary aquifers: From asymmetries to environmental protection. Front. Norte
2018
,
30, 129–154. [CrossRef]
85. Brownell, H.; Eaton, S.D. The Colorado River salinity problem with Mexico. Am. J. Int. Law 1975,69, 255–271. [CrossRef]
86. Mumme, S.P.; Collins, K. The La Paz Agreement 30 years on. J. Environ. Dev. 2014,23, 303–330. [CrossRef]
87.
Alley, W.M. Five-Year Interim Report of the United States—Mexico Transboundary Aquifer Assessment Program: 2007–2012.
Available online: https://pubs.usgs.gov/of/2013/1059/pdf/ofr2013-1059.pdf (accessed on 23 June 2021).
88.
IBWC. Joint Report of the Principal Engineers Regarding the Joint Cooperative Process United States-Mexico for the Transbound-
ary Aquifer Assessment Program. 2009. Available online: https://www.ibwc.gov/Files/Minutes/Joint_Report_TAAP_081909
.pdf (accessed on 6 August 2021).
89.
Rojo, H.A.; Bredehoeft, J.; Lacewell, R.; Price, J.; Stromberg, J.; Thomas, G.A. Sustaining and Enhancing Riparian Migratory Bird
Habitat on the Upper San Pedro River: Public Review Draft. 1998. Available online: https://searchworks.stanford.edu/view/47
82615 (accessed on 6 August 2021).
90.
Eckstein, G.E. Managing buried treasure across frontiers: The International Law of Transboundary Aquifers. Water Int.
2011
,36,
573–583. [CrossRef]
91.
Memorandum of Understanding between City of Juárez, Mexico Utilities and the El Paso Water Utilities Public Services Board
and the City of El Paso, Texas (MOU). 1999. Available online: http://www.internationalwaterlaw.org/documents/regionaldocs/
Local-GW-Agreements/El-Paso-JuarezMoU.pdf (accessed on 21 June 2021).
92.
Pool, D.R.; Dickinson, J.E. Ground-Water Flow Model of the Sierra Vista Subwatershed and Sonoran Portions of the Upper San Pedro Basin,
Southeastern Arizona, United States, and Northern Sonora, Mexico; No. 2006-5228; U.S. Geological Survey: Reston, VA, USA, 2007.
93.
Wallace, C.S.A.; Villarreal, M.L.; Norman, L.M. Development of a High-Resolution Binational Vegetation Map of the Santa Cruz River
Riparian Corridor and Surrounding Watershed, Southern Arizona and Northern Sonora, Mexico; No. 2011-1143; U.S. Geological Survey:
Reston, VA, USA, 2011.
94.
Villareal, M.L.; Norman, L.M.; Wallace, C.S.A.; Van Riper, C. A Multitemporal (1979–2009) Land-Use/Land-Cover Dataset of the
Binational Santa Cruz Watershed; U.S. Geological Survey: Reston, VA, USA, 2011.
95.
Callegary, J.B.; Heilman, J.A.; Tapia-Villaseñor, E.M.; Knight, J.E. San Pedro River Aquifer Data Release—Transboundary Aquifer
Assessment Program (TAAP); U.S. Geological Survey Data Release: Reston, VA, USA, 2018. [CrossRef]
96.
Dirks, K.T. Trust in leadership and team performance: Evidence from NCAA basketball. J. Appl Psychol.
2000
,85, 1004. [CrossRef]
97.
Megdal, S.B. The cooperative framework for the Transboundary Aquifer Assessment Program: A model for collaborative
transborder studies. Water Resour. Impact 2018,20, 10–11.
98.
Mechlem, K. Past, present and future of the International Law of Transboundary Aquifers. Int. Community Law Rev.
2011
,13,
209–222. [CrossRef]
99.
Tapia-Villaseñor, E.M.; Megdal, S.B. The U.S.-Mexico Transboundary Aquifer Assessment Program as a model for transborder
groundwater collaboration. Water 2021,13, 530. [CrossRef]
100.
Coppola, M.C. Blaze in Nogales, Sonora Battled from Both Sides of the Border. Nogales International (Nogales, AZ).
10 May 2012
.
Available online: https://www.nogalesinternational.com/news/blaze-in-nogales-sonora-battled-from-both-sides-of-the/
article_3267761e-9b0d-11e1-85e7-001a4bcf887a.html (accessed on 6 August 2021).
... Petersen-Perlman et al. [17] refer to the TAAP as an example of a binational collaborative effort for the scientific assessment of aquifers shared between Mexico and the United States. Sabet [18] conducted qualitative research to characterize a binational civil society collaboration to address water-related problems in the Mexico-U.S. border region. Sabet suggests collaboration and cooperation could respond better to borderland water problems if more citizens and local governments were involved. ...
... Municipal representatives said they collaborate with researchers, CONAGUA, state governments, NGOs, and scholars from State Universities. These interactions lack bi-directionality, where each actor informs and enhances the other Petersen-Pearlman et al., 2021, [18]. In summary, institutions and stakeholders look to collaborate with federal and state governments, but there is not the same response from these authorities. ...
Article
Full-text available
Analyzing collaborative practices among water governance institutions is key to generating timely information for stakeholders, policymakers, and researchers -as these are rethinking their goals and network structures to find the most productive avenues for collective work. This study draws on existing collaboration theories to characterize and analyze science-policy interactions between researchers, water managers, non-governmental organizations, and consultants who have participated or currently participate in water management and recharge projects in Mexico. We sampled 70 people that had worked or are working on water recharge projects in eight Mexican states in three broad regions: Baja California, Baja California Sur, Chihuahua, Sonora (northern); Estado de Mexico, San Luis Potosí, Mexico City (central); and Oaxaca (southern). Participants represented research institutions, non-governmental organizations, universities, federal, state, and municipal governments, and consultants. The data were collected using a mixed-methods approach (i.e., semi-structured interviews; online surveys). We identified science-policy interactions between researchers, policymakers, and non-governmental organizations critical to effectively developing and implementing water recharge projects. Our results find that trust and stakeholder participation are the most critical elements for building collaborative relationships. Finding ways to supersede structural challenges and promote science-policy collaboration among sectors and interagency with water management responsibilities will help achieve environmental and policy goals and increase water recharge development across Mexico.
... One of these aquifers is the Transboundary San Pedro Aquifer (TSPA), located in the Arizona-Sonora border region. The TSPA is a Transboundary Aquifer Assessment Program (TAAP) aquifer of focus, which is a joint effort between the United States and Mexico to evaluate shared aquifers [20][21][22][23]. A number of studies and technical activities have been carried out through the TAAP in Arizona and Sonora over the last decade (i.e., [22][23][24][25]). ...
... The TSPA is a Transboundary Aquifer Assessment Program (TAAP) aquifer of focus, which is a joint effort between the United States and Mexico to evaluate shared aquifers [20][21][22][23]. A number of studies and technical activities have been carried out through the TAAP in Arizona and Sonora over the last decade (i.e., [22][23][24][25]). For example, in 2016 the International Boundary and Water Commission published the Binational Study of the Transboundary San Pedro Aquifer [24]. ...
Article
Full-text available
Hydrogeomorphology is an emerging discipline that studies the relationship between landforms and hydrology, focusing on groundwater and surface water interactions. This study presents the methodology for the elaboration of a hydro-geomorphological map oriented to illustrate the relationships between the aquifer components and geomorphological characteristics in the United States-Mexico Transboundary San Pedro Aquifer (TSPA). This information contributes to a further understanding of the TSPA, facilitates the location of groundwater recharge and discharge zones, is useful for the development of sustainable groundwater management strategies, and could be useful in developing conceptual and numerical groundwater models for the region.
... Furthermore, cooperative management of transboundary waters contributes to water security [10] and has been found to lead countries towards more cooperative relationships [11]. While the water cooperation discourse has largely focused on rivers and lakes [12][13][14][15][16][17], and more recently also on aquifers [18][19][20], we hypothesize that wetlands, too, require cooperation among states in order to ensure the sustainability of wetlands management. Indeed, Milanes-Murcia et al. [21] posit that "integration and cooperation are fundamental in proper management of transboundary wetlands". ...
Article
Full-text available
The water governance discourse focuses on the use of water from rivers—and increasingly lakes and aquifers—for a variety of human uses, often in a competing manner. Largely missing from this discourse are wetlands. Despite an increased understanding of the benefits of wetlands, global wetland area continues to decrease. Particularly in international river basins, upstream water withdrawals are having negative impacts on wetlands, and the communities that rely on them downstream. Following the framework of transboundary water cooperation, the joint management of transboundary wetlands in the context of integrated basin management may prevent conflict and lead to further collaboration. As a first step to understand how wetlands may fit into water cooperation, this research employs spatial analysis and document analysis to identify transboundary wetlands and possible institutions to manage them, providing a basis for analyzing conflict and cooperation dynamics in them. The products of this research are a database and map of 300 transboundary wetlands, including the river basins (and, when applicable, the River Basin Organizations) they fall within.
... The issue of finance deserves special attention in this perspective [92]. A key issue is fostering productive cooperation while incorporating local context [69,72,77,[93][94]. ...
Article
Droughts have severe impacts on the economy, society, and environment. They also have impacts on groundwater and vice versa. While most analyses consider drought and groundwater as disconnected, we argue that drought and groundwater management should be conjunctively considered. This article presents some key interconnections, identifies challenges, and discusses illustrative policy responses. We highlight several advancements found in international scientific research and describe future directions for drought and groundwater management. While many technological innovations have improved our understanding of drought and groundwater’s complex nature, policy and governance advances have not kept pace.
Article
Full-text available
Across a number of issues, nation-state borders work to reduce feelings (imaginations) of mutual belonging and shared fate, and together with this, reduce equitable and practical collective decision-making and action requiring these basic assumptions. I proceed by identifying specific processes and mechanisms by which nation-state borders produce separation. I also address processes of mutual recognition that occur at borders, arguably because borders concentrate people and activities that favor or even require creation frameworks for mutual decision-making and action. This would involve dialogues, decisions, and practical administrative interactions suited to the phenomenon, rather than arbitrarily limited and obstructed by singular bounded state institutions. By creating diverse arenas and spaces of interested participants having shared practical concerns, and by imbuing these with a social imaginary of being a commons, it might be possible to address this problematic effects of bounded nation-states.
Article
Full-text available
In the parched Upper Santa Cruz River Basin (USCRB), a binational USA–Mexico basin, the water resources depend on rainfall-triggered infrequent flow events in ephemeral channels to recharge its storage-limited aquifers. In-situ data from the basin highlight a year-round warming trend since the 1980s and a concerning decline in average precipitation (streamflow) from 1955–2000 to 2001–2020 by 50% (87.6%) and 17% (63%) during the winter and summer, respectively. Binational sustainable management of the basins water resources requires a careful consideration of prospective climatic changes. In this article we review relevant studies with climate projections for the mid-21st century of four weather systems that affect the region’s precipitation. First, the North American Monsoon (NAM) weather system accounts for ~60% of the region’s annual rainfall. The total NAM precipitation is projected to decline while heavy rainfall events are expected to intensify. Second, the frequency of the pacific cold fronts, the region’s prevalent source of winter precipitation, is projected to decline. Third, the frequency and intensity of future atmospheric rivers, a weather system that brings winter rainfall to the region, are projected to increase. Fourth, the frequency and intensity of large eastern pacific tropical cyclones (TC) are expected to increase. On rare occasions, remnants of TC make their way to the USCRB to cause storms with considerable impact on the region’s water resources. In contrast to the high confidence projections for the warming trend to persist throughout the mid-21st century, the precipitation projections of these four weather systems affecting the region encompass large uncertainties and studies have often reported contradicting trends. An added source of uncertainty is that the USCRB is located at the periphery of the four rain-bearing weather systems and small mesoscale changes in these weather systems may have accentuated impacts on their edges. Despite the high uncertainty in the projections of future precipitation, the early 21st century drying trend and the projected mid-21st century decline in precipitation events serve as a pressing call for planning and actions to attain sustainable water resources management that reliably satisfies future demands.
Article
Full-text available
The assessment of transboundary aquifers is essential for the development of groundwater management strategies and the sustainable use of groundwater resources. The Transboundary Aquifer Assessment Program (TAAP) is a joint effort by the United States and Mexico to evaluate shared aquifers. This study examines the TAAP Cooperative Framework as a guide for further transboundary groundwater collaboration. We compared lessons learned from six transboundary aquifers that currently have mechanisms for groundwater collaboration to identify common elements of collaboration. Though the TAAP Cooperative Framework governs an assessment-only program, the elements of collaboration included are consistent with the principles of other institutional agreements around the world. Importantly, all the analyzed agreements included a knowledge-improvement phase, which is the main objective of the TAAP Cooperative Framework. The present study finds evidence of successful outcomes within the TAAP Cooperative Framework consistent with available transboundary groundwater management agreements, demonstrating that this approach is suited to serve as a model for those wishing to engage in transborder aquifer assessments. Furthermore, the TAAP elements of collaboration can help to establish the meaningful and robust binational cooperation necessary for the development of U.S.-Mexico groundwater management agreements at the aquifer level.
Article
Full-text available
Knowledge is widely considered a key ingredient for the effective and sustainable governance of the environment. In transboundary settings – i.e., where political boundaries cross natural resource system boundaries – there are considerable barriers to knowledge production and use. Resulting knowledge gaps can be barriers to governance. This research examines three case studies in which international river basin organizations, tasked with facilitating cooperation in transboundary river basins, recognized and addressed knowledge gaps to support governance of shared waters. We synthesize across the three case studies to develop a typology of knowledge gaps and the strategies used to address those gaps. In identifying common types of knowledge gaps and the on-the-ground strategies used to fill them, this research provides an important framework for assessing and theorizing knowledge at the transboundary scale, as well as useful recommendations and examples for practitioners seeking to develop that knowledge.
Article
Full-text available
Study region Africa, Latin America, Europe. Study focus Through the extensive study and mapping of the world’s aquifers that lie astride the international boundary lines of sovereign States, ISARM has awakened concerned States to the existence of aquifers stretching beyond their borders, and precipitated cooperation in generating a body of knowledge that facilitated cooperation in governance arrangements for such aquifers. In parallel, ISARM influenced the shape and direction of the United Nations “Draft articles on the law of transboundary aquifers” appended to UN Resolution 63/124 of 2008. Both stimulated cooperation among concerned States, and provided a frame of reference for the legal grounding of such cooperation in aquifer-specific agreements. New hydrological insights Through this synergistic paradigm, ISARM has made an impact on the shape and direction of cooperation in the Guaraní Aquifer in South America, and in the Iullemeden and Taoudeni/Tanezrouft Aquifer Systems (ITAS) in the Sahel region of Africa. It is having an influence on the shape and direction of cooperation being negotiated on the Stampriet Aquifer System in Southern Africa, and on the Ocotepeque-Citalá Aquifer in Central America. The link of ISARM to other international aquifer agreements on record is tenuous, and ISARM’s influence on their generation speculative. The visibility of ISARM has faded since 2012, however its legacy is lasting.
Article
The United States and Mexico have engaged in hydrodiplomacy—a practice of transboundary water management that blends water diplomacy and science diplomacy--for more than 75 years, since the adoption of the Treaty of 1944 and the creation of the International Boundary and Water Commission. We examine six major turning points in U.S.-Mexico hydrodiplomacy to ascertain the key factors in the region’s history of resolving transboundary water issues. We find that recognized adaptive governance indicators—such as social learning, sustained relationships, flexible governance mechanisms, and state and non-state networks are essential elements of hydrodiplomacy. Our research suggests that robust and foundational institutions comprise another key indicator of adaptive governance specifically in transboundary contexts. A commitment to both science and diplomacy have been important components underlying the effectiveness of hydrodiplomacy in the border region. Binational networks involving diverse state and non-state actors at multiple scales have increasingly played a pivotal role in shaping desirable hydrodiplomatic outcomes in the region.
Article
Transboundary waters are characterized by diverse and complex socio-politico-economic obstacles to effective water management. We examine five distinct cases in the arid Americas – in locations from the US–Mexico border to the Andes mountains – employing water security as a conceptual prism to unravel the multiple and varied attributes of transboundary water challenges. We describe how borders complicate water security in arid regions and explore how institutional arrangements and practices – within and across jurisdictions – respond to these challenges. We find that institutional capacity is needed on multiple levels for effective water management, and institutions must be responsive and flexible to change.