Data sharing in transboundary waters:
Current extent, future potential and practical 
recommendations

Data exchange in transboundary waters is fundamental to advance 
cooperation in water management. Nonetheless, the degree to which data 
are actually shared is falling short of basin-level and international targets. 
A global assessment revealed that a reasonable proportion of river basins 
exchange some data, but the breadth of such exchange is often limited 
and not regular. More in-depth examination of African basins nonetheless 
suggests that a real need for, and use of, water data appears to motivate 
exchange. Indeed, evidence suggests that data exchange needs which are 
more directly felt enhance exchange, e.g., the direct need to minimize flood 
impacts or manage transboundary infrastructure. As such, data sharing is 
much more likely to be considered as being successful if it responds to a 
palpable need and serves practical uses. Also, in developing data exchange 
programs, it may be prudent to adopt a focused and sequential approach to 
data exchange that starts with a short-list of most needed parameters.

Downloading data in a monitoring borehole on the Tuli Karoo transboundary aquifer  
(photo: F. Ramusiya).

Water Policy Brief - 43
Based on externally peer-reviewed  

published material

Key messages
■  Data exchange in transboundary waters is 

insufficient. To achieve effective river basin 
management and efficient progress toward 
global development targets, a substantial 
augmentation in the volume and frequency 
of data exchange is needed. The Global 
Acceleration Framework (UN-Water 2020) puts 
data and information, and its exchange, at the 
core of attaining development targets. 

■   Data exchange benchmarks can benefit 
from adapting to basin contexts. While 
global legal instruments (e.g., the 1992 Water 
Convention and 1997 Watercourses Convention) 
set out general commitments to exchange 
data, basin-specific cooperation requires 
those general commitments to be adapted to 
particular contexts. 

■  Data exchange can start with a ‘first-
step’ set of baseline parameters. Given the 
widespread challenges of data exchange, it 
may be beneficial to start on a small scale 
initially and scale up progressively. Ideally, 
initial data exchange efforts should be focused 
on parameters of the greatest data needs in at 
least three key categories: (i) water quantity 
data; (ii) water quality data according to locally 
relevant parameters; and (iii) water use data.

■  Periodic assessments of data exchange 
needs can ensure that data exchange aligns 
with evolutions in needs. Periodic review of 
data sharing needs may help to ensure that 
data exchange modalities remain up-to-date. 
Such data exchange needs assessments could 
form part of activities such as river basin plans 
and data exchange protocols. 

■  Need for data exchange can be promoted 
by encouraging the practical application of 
data. The use and application of data can be 
stimulated. Collaborating with universities and 
research institutes, for example, may enhance 
the use of data in activities such as modelling 
of alternative dam operations, water quality 
risk assessments, or environmental impacts. 



IWMI  •  2 Water Policy Brief 43  •  Data sharing in transboundary waters: Current extent, future potential and practical recommendations

Figure 1. River basins surveyed for data exchange and needs assessment in this study (design: Ranjith Alankara). 

Introduction
Why data exchange in river basin management? Intrinsic 
interconnections of natural systems call for integration of 
data to enable holistic management of natural resources 
for sustainable development. In river basins that cross 
international borders, development in one state can negatively 
affect other states. Further, integrated management – based 
on integrated data – can optimize the total benefits derived 
from water management and support cooperation. For 
example, in the Mekong River Basin, monitoring and exchange 
of data on river flows helps to balance the benefits derived 
from ecological processes and hydropower generation (MRC 
2021). In contrast, fragmented management – based on 
disaggregated data – can limit the benefits derived from water 
management and drive tension.

International principles, practical challenges and 
knowledge gaps. Under the 1992 Water Convention and the 1997 

United Nations Watercourses Convention, countries in a shared 
watercourse are obliged to exchange data and coordinate on 
water management. As reasonable as this may seem, evidence 
(e.g., Thu and When 2016; Plengsaeng et al. 2014) suggests that 
several challenges routinely impede the smooth flow of data. 
In the Mekong, for example, challenges include a lack of trust, 
limited availability of data and inefficient data sharing systems. 
Basic assessments of whether or not data are exchanged 
have been conducted as part of Indicator 6.5.2 (proportion of 
transboundary basin area with an operational arrangement 
for water cooperation) of the United Nations Sustainable 
Development Goals (SDGs) (UN-Water 2021). However, global 
assessments have been unable to analyze the extent of data 
exchange or the drivers of and constraints to data exchange. 
The investigations synthesized in this brief represent the first 
systematic examination of the breadth of, and variation in, data 
exchange in a set of transboundary watercourses (Figure 1). It is 
also the first attempt to understand the degree to which practical 
data needs drive exchange.

Approach. A framework was developed to capture the 
main elements of data exchange across transboundary 
river basins: scope of exchange, frequency of exchange and 
the modalities of exchange (Table 1). Within the scope of 
exchange, the breadth of exchange was assessed through 
parameters related to surface water and groundwater levels, 
water quality and water use. In order to be meaningfully 
utilized and translated into decisions, data have to be 
exchanged within viable time frames. It was, therefore,

important to assess the frequency at which data are 
exchanged, e.g., real time, daily, monthly, quarterly, annually 
or in an ad hoc fashion. To assess the modalities of data 
exchange, two indicators were selected: (i) existence of  
formal data exchange protocols among basin countries; 
and (ii) means of transmitting data, e.g., telephone, email, 
online platform. Data exchange needs were also assessed for 
basins in Africa by developing and populating an analogous 
framework through a questionnaire survey.



IWMI  •  3Water Policy Brief 43  •  Data sharing in transboundary waters: Current extent, future potential and practical recommendations

Figure 2. Exchange of (a) river flow data, and (b) groundwater level data.

Table 1. Data exchange assessment framework. 

Category Parameters 

Scope of exchange • Surface water parameters - river flow, dam storage  
 • Groundwater parameters - groundwater levels 
 • Water quality data - electrical conductivity, suspended sediment, nitrates, pH,   
  microbiological quality 
 • Water use - surface water abstraction 

Frequency of exchange • Real time 
 • Daily 
 • Monthly 
 • Quarterly 
 • Annually 
 • Ad hoc

Modalities • Existence of formal data exchange protocols 
 • Means of transmitting data

Data exchange needs • Agriculture 
 • Hydropower 
 • Environmental water requirements  
 • Urban water supply 
 • Disaster risk management

Findings 

How much data are exchanged? 
Limited scope of exchanged data. River flow data are 
shared most widely and exchanged in 76% of the river basins 

albeit at varying frequencies (Figure 2). Water quality data are 
shared in less than half the basins and only 32% of the basins 
exchange groundwater data. While it is encouraging that 76% 
of the basins exchange river flow data, there are concerns 
regarding the remaining 24% of basins which do not exchange 
river flow data.

40%

24%

12%

24%

Real time - daily

Monthly/annually

Ad hoc

No reported exchange
No reported exchange

16%

16%

68%

Quarterly/annually

Ad hoc

Low frequencies and high latency in data exchange 
limit effective river basin management. The benefits of 
regular data exchange are numerous. These benefits include 
identification of extreme conditions  (e.g., floods and droughts) 
that require urgent action, and identification of long-term 
climatic or water quality trends, for example, that require 
changes in planning. Unfortunately, ad hoc exchanges were 
commonly observed and this raises concerns over the extent 
to which such irregularity in data sharing constrains river basin 
management. Minimizing data latency – the time lag between 
measurement and sharing of data – is, therefore, of critical 
importance to inform processes such as flood and drought 
monitoring and forecasting to enable appropriate reaction 

times. Of the basins, 40%, 24% and 12% shared river flow 
data in real time, monthly/annually and in an ad hoc fashion, 
respectively, and 24% did not exchange any data at all  
(Figure 2).

Protocols have no clear impact on data exchange, but 
means of transmission may. Although it was thought that 
formal data exchange protocols would likely increase the 
flow of data across borders, basins with such protocols do 
not necessarily exchange river flow data more frequently. 
However, where multiple means of transmitting data (e.g., 
telephone, email and online platforms) were in place, more 
frequent exchange of river flow data was evident. Multiple 



IWMI  •  4 Water Policy Brief 43  •  Data sharing in transboundary waters: Current extent, future potential and practical recommendations

means of transmitting data were mostly used in combination. 
Although there may be technical barriers in less developed 
contexts, online platforms may enable greater exchange of 
data and provide a range of applications to reap the benefits 
of a harmonized database system.

Formulation of data exchange clauses in river basin 
agreements could encourage data exchange.  Across river 
basin agreements, the responsibility for data exchange falls on 
either a River Basin Organization (RBO) secretariat or individual 
state parties. Further, the normative language within basin 
agreements and protocols varies from the use of firm wording 
as ‘shall cooperate’ (e.g., the Mekong) to ‘softer’ language such 
as ‘cooperate in good faith’ (e.g., the Zambezi), a formulation 
which may be interpreted as optional. In other cases (e.g., the 
Okavango), the obligation to exchange data is limited by ‘… the 
extent permitted by its own [national] laws and procedures’. 
These variations in the formulation of data exchange clauses in 
river basin agreements may impact the levels of exchange.

How much data exchange is needed?
Basin countries are thirsty for more data. Demand for data 

exceeds actual data exchanged. Basin countries were largely 
in need of data and there is a shortage of it. Expressed need 
across different parameters ranged from 70% to 100% with 
the highest need recorded for precipitation and river flow 
data and the lowest for data on agricultural return flows and 
wastewater discharge quantities. Although the challenges 
surrounding data availability are multifaceted, there was 
consensus on the need for more data to be exchanged among 
basin countries.

Where data needs are felt, data needs are satisfied. 
Assessing need satisfaction against a core set of parameters 
(river flow, reservoir storage, pH, electrical conductivity and 
precipitation) showed that needs were met in the Lake Chad, 
Pungwe and Zambezi river basins, but needs were not met 
in the Limpopo, Ruvuma, Okavango and Volta river basins 
(Table 2). Notably, the basins where needs were mostly met 
appeared to possess transboundary water infrastructure 
(Niger, Orange Senqu, Senegal, Zambezi) or a pressing 
disaster risk reduction challenge such as low lake levels 
(Lake Chad) or floods (Pungwe). Such issues are presumed to 
drive felt need – i.e., experienced on an operational level – 
for data exchange.

Table 2. Levels of need satisfaction in African river basins.  

Levels of need satisfaction Basin country units

0-24% • Botswana, Mozambique and Zimbabwe in the Limpopo Basin  
Needs unmet • Mozambique and Tanzania in the Ruvuma Basin 
 • Angola, Botswana and Namibia in the Okavango Basin  
 • Ghana and Togo in the Volta Basin

25-50% • South Africa in the Orange-Senqu Basin 
Some needs met • South Africa in the Limpopo Basin  
 • Angola and Namibia in the Cuvelai Basin 

50-74% • Mali, Niger and Nigeria in the Niger Basin 
Needs mostly met  • Malawi, Mozambique, Zambia and Zimbabwe in the Zambezi Basin  
 • Guinea, Mali and Senegal in the Senegal Basin 
 • Namibia in the Orange-Senqu Basin

75-100% • Angola in the Zambezi Basin 
Needs met • Chad, Niger, Nigeria and Central African Republic in the Lake Chad Basin 
 • Mozambique and Zimbabwe in the Pungwe Basin

Key findings
Current levels of data exchange are too low. Although there 
are encouraging levels of data exchange on one core parameter 
(river flow), the scope of data exchanged is limited; data on 
groundwater levels and abstraction, for example, are not widely 
shared. Part of the issue undoubtedly stems from the fact that 
data are not collected. In any case, the efficacy of formal data 
exchange protocols – seen as being important to structure 
data exchange – was not apparent as some basins with such 
protocols were not exchanging all stipulated data.

Practical implications. The bottom line is a less than ideal 
situation for effective river basin management and constrained 
progress towards achieving development goals. Across the 25 

river basins assessed, the levels of exchange are low except for the 
exchange of river flow data. This was also the case in basins with 
advanced levels of water cooperation. Such limited data exchange 
potentially jeopardizes decisions related to, for example, water 
allocation, flood and drought management, or ecosystem services. 

Start small. A gradual increase in the types of data exchanged 
may provide a more effective approach to the realization of data 
sharing than aiming for a comprehensive framework from the 
outset. In a transboundary watercourse where data have not 
previously been shared, the first step may be generating and 
exchanging essential data to understand the fundamentals of 
the shared resource (Box 1). Basin countries can then build on 
this initial step to expand the scope of exchange parameters in 
response to identified needs.



IWMI  •  5Water Policy Brief 43  •  Data sharing in transboundary waters: Current extent, future potential and practical recommendations

Box 1. Towards an integrated picture of the shared Tuli Karoo Aquifer.

The Tuli Karoo Transboundary Aquifer Area is shared by Botswana,  
South Africa and Zimbabwe (Figure 3). Not much was known about  
groundwater levels and how it flows and interacts with surface  
water resources. Basin countries agreed that there was a need to  
have harmonized monitoring across the aquifer to generate data.  
In an initial effort to achieve this, a monitoring system was  
designed and data loggers were installed in selected monitoring  
boreholes across the three countries. Data on groundwater levels,  
electrical conductivity and pH were collected each hour and  
transmitted (Figure 4) to a shared server, which could be accessed 
by each country. 

 

 

 
      

Stimulate need. Incentives for data exchange may not 
be sufficiently evident to those involved in river basin 
management. One way to stimulate data sharing is to focus 
on a common need, e.g., flood or drought mitigation, or 
improving water quality to support ecosystem services. 
Such practical and tangible uses of data may serve as a 

catalyst that enables increased data flows (Box 2). Data-
driven decisions and policies have become more critical, 
particularly with the increased frequency of extreme weather 
events as a result of climate change. Therefore, response 
times have to be shorter. An adequate flow of data is needed 
to enable such responses.

Data logger used for measuring soil moisture in Ghana (photo: Hamish John Appleby/IWMI).

Figure 4. Testing data transmission  
(photo: F. Ramusiya).

Figure 3. Map showing the Tuli Karoo Transboundary Aquifer Area 
shared by Botswana, South Africa and Zimbabwe  
(design: G. Y. Ebrahim).

Note: DRC - Democratic Republic of the Congo. 



IWMI  •  6 Water Policy Brief 43  •  Data sharing in transboundary waters: Current extent, future potential and practical recommendations

Box 2. Data exchange needs assessments as an ongoing part of river basin management.

One of the first steps to enabling data exchange in transboundary river basins should be the assessment of data needs. 
While this may seem an obvious step to realizing data-driven river basin management, it is nonetheless not often 
implemented. Amplifying data needs assessments as a critical first step to enable greater exchange could help address 
barriers to data exchange. Needs assessments should be carefully formulated to capture actual needs as opposed to 
needs based on best practices and standards. When data are targeted at a particular need, they are more likely to achieve 
measurable outcomes. Spending more time on this first step could sensitize basin countries to data exchange needs and 
help set common objectives.  

Implementation of a data needs assessment could follow four steps (Figure 5). Following this implementation, core 
parameters on which data exchange is agreed can be consolidated and codified. A working group can then be created to 
review the efficacy of data exchange efforts, and such efforts can be revised periodically based on evolving needs.

 

 

 
 
 
Figure 5. Steps to incorporate a data exchange needs assessment into river basin management.

Concrete Next Steps

Five key interventions targeted at basin and country levels could 
spur the exchange of water data to enable effective river basin 
management and speed up achievement of development goals.

1. Integrate data exchange into river basin activities. Data 
exchange should form an explicit part of ongoing activities 
within river basin management, such as development and 
disaster reduction projects. For example, streamlining 
data into activities (e.g., flood management, irrigation 
infrastructure development, establishing environmental 
flows, etc.) within climate adaptation plans can strengthen 
national data management processes and thus facilitate 
smoother transboundary data exchange.

2. Enhance and complement global directives through 
targeted benchmarks. Identifying core categories for 
data exchange, such as water quantity, water quality and 
water use, according to locally relevant needs may provide 
a practical basis for exchange. In addition, the potential 
of SDG Indicator 6.5.2 as a means to trigger increased 
transboundary data exchange may be further harnessed.

3. Develop and apply a tool for data needs assessments 
in shared waters. Assessing needs is a critical step in 
providing a clear context and incentives for data exchange. 
Focusing data exchange efforts around common needs in a 

basin may potentially incentivize greater data exchange. An 
efficient needs assessment tool and procedure to facilitate 
the identification of such needs are thus central to increasing 
data exchange. It is also important to build capacity (both 
human and technical) to use such a tool. 

4. Broker and establish modalities for review and 
evaluation of data exchange. Through partnerships 
with river basin organizations, support can be provided 
for strengthening provisions in basin agreements and 
instruments, such as protocols, on specific parameters to 
be exchanged at specified frequencies. Where activities 
for sustained implementation can be elaborated, 
embedding the necessary flexibility within these 
provisions to satisfy the evolving nature of data exchange 
needs is critical.

5. Optimize and adapt the use of online platforms 
to enhance data exchange across river basins. In 
the present context of a rapidly progressing digital era, 
transboundary data exchange platforms may unlock benefits 
from greater data processing efficiency. As such, addressing 
barriers to the use of online platforms is an important 
task particularly in developing countries, where adapting 
platforms to the realities of limited internet access and 
electricity shortages through low-tech user interface with 
low bandwidth settings or the use of mobile applications may 
prove more practical.

Assess the need 
for data

Consolidate core 
data that will meet 
the needs identified

Define modalities 
that will optimize 

exchange

Establish a working 
group that reviews, 

revisits and updates data 
exchange modalities



IWMI  •  7Water Policy Brief 43  •  Data sharing in transboundary waters: Current extent, future potential and practical recommendations

Cahora Bassa Dam, lower Zambezi, Mozambique (photo: Richard Beilfuss). 

References
MRC (Mekong River Commission). 2021. Situation report on dry season hydrological conditions in the Lower Mekong River Basin: 
November 2020– May 2021. Vientiane, Laos: MRC Secretariat. Available at https://www.mrcmekong.org/assets/Publications/Dry-
season-situation-report-Nov-2020-to-May-2021.pdf (accessed on November 11, 2021). 

Plengsaeng, B.; Wehn, U.; van der Zaag, P. 2014. Data-sharing bottlenecks in transboundary integrated water resources 
management: A case study of the Mekong River Commission’s procedures for data sharing in the Thai context. Water International 
39(7): 933–951. https://doi.org/10.1080/02508060.2015.981783

Thu, H.N.; Wehn, U. 2016. Data sharing in international transboundary contexts: The Vietnamese perspective on data sharing in the 
Lower Mekong Basin. Journal of Hydrology 536: 351–364. https://doi.org/10.1016/j.jhydrol.2016.02.035

UN-Water. 2020. The Sustainable Development Goal 6 global acceleration framework. Geneva, Switzerland: UN-Water.

UN-Water. 2021. Progress on transboundary water cooperation: Global status of SDG indicator 6.5.2 and acceleration needs. Paris, 
France: United Nations, and United Nations Educational, Scientific and Cultural Organization (UNESCO). 



IWMI  •  8 Water Policy Brief 43  •  Data sharing in transboundary waters: Current extent, future potential and practical recommendations

International Water
Management Institute (IWMI)

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strengthening, dialogue and policy analysis to support implementation 
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change and inclusive economic growth. Headquartered in Colombo, Sri 
Lanka, IWMI is a CGIAR Research Center and leads the CGIAR Research 
Program on Water, Land and Ecosystems (WLE).

Source
This Water Policy Brief is largely adapted from the following sources:

Mukuyu, P.; Lautze, J.; Rieu-Clarke, A.; Saruchera, D.; McCartney, M. 2020. The devil’s in the details: Data exchange in transboundary 
waters. Water International 45(7-8): 884–900. https://doi.org/10.1080/02508060.2020.1850026

Mukuyu, P.; Lautze, J.; Rieu-Clarke, A.; Saruchera, D.; McCartney, M. Do needs motivate the exchange of data in transboundary 
waters? Water International. In submission.

Acknowledgments
We thank the country specialists and River Basin Organization staff who took part in this study. The support of collaborating 
partners, International Union for Conservation of Nature (IUCN) and Northumbria University, is also acknowledged and appreciated.

This research was carried out as part of the CGIAR Program on Water, Land and Ecosystems (WLE) and supported by Funders 
contributing to the CGIAR Trust Fund (https://www.cgiar.org/funders/). 

Contacts
Patience Mukuyu, Researcher - Transboundary Water Management, IWMI, Pretoria, South Africa (p.mukuyu@cgiar.org)

Jonathan Lautze, Research Group Leader – Integrated Management of Basins and Aquifers, IWMI, Pretoria, South Africa  
( j.lautze@cgiar.org)

IWMI is a CGIAR Research Center

Citation

International Water Management Institute (IWMI). 2021. Data sharing in transboundary waters: Current extent, future potential and practical 
recommendations. Colombo, Sri Lanka: International Water Management Institute (IWMI). 8p. (IWMI Water Policy Brief 43).  
doi: https://doi.org/10.5337/2021.232

/ data management / information exchange / international waters / river basin management / frameworks / water management / surface water / 
groundwater / parameters / data transmission / modelling / water use / water quality / risk assessment / environmental impact / water policies / 
international cooperation / international agreements / floods / drought / monitoring / Africa /

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