Page 21 - CIWA Water Data Revolution Overview Report

Water Data Revolution: Closing the data gap for transboundary water in Africa

14 15
patterns. , It promotes transparent decision-making and enables equitable water distribution,
which is critical in mitigating disputes among riparian countries. Water accounting also facilitates
the identification of opportunities for joint investment projects and supports the long-term
sustainability of water resources. By creating a common understanding of water availability and

demand, it contributes to more informed and cooperative resource management across different
scales, helping to prevent over-exploitation and ensuring that water is used efficiently for
economic and environmental benefits

A water accounting system is implemented using a standardized methodology and nomenclature.

In recent years, Water Accounting Plus (WA+), developed by the International Water
Management Institute (IWMI), has become one of the most widely used approaches. WA+
addresses the limitations of traditional methods by relying on remote sensing technology, open-
source hydrological models, and global datasets, rather than relying solely on national-level
hydro-meteorological data. This approach offers a significant advantage by enabling consistent
and accurate water accounts at different scales, even in regions with limited ground-based data,
thanks to the use of satellite-derived information. This is especially beneficial in the context of
transboundary river basins, where data access can be challenging due to the participation of

multiple countries. In such cases, remote sensing eliminates the need for extensive data
collection, which can be resource-intensive and often hinders cross-border collaboration by
creating logistical barriers.

WA+ uses satellite-derived data for key meteorological variables (e.g., evapotranspiration and

precipitation) to calculate water balances without requiring direct measurements of water
withdrawals or return flows. By leveraging advancements in earth observation technology, WA+
provides reliable, continuous, and gridded data on water resources from field to basin scales,
ensuring consistency across regions and transboundary basins. This approach offers a
comprehensive understanding of water availability, use, and sustainability and is increasingly
used to support water resource management and policy decisions, especially in areas where local
data is scarce.

Another key advantage of using the WA+ is that it provides a replicable framework. This means
that Water Accounting dashboards can be implemented across different basins, creating a
common foundation for analytics among RBOs. This approach offers significant benefits,
particularly by enabling the future scalability of the CIWA initiative to support additional RBOs,

14 GWP (Global Water Partnership). (2014). Water Accounting in Transboundary Basins: A Tool for Ensuring Equitable and Sustainable Water
Management. Global Water Partnership.
15 FAO. (2018). Water Accounting: Framework for Improving Water Productivity and Sustainability in Agriculture. Food and Agriculture
Organization of the United Nations.
20