CONCLUSIONS AND RECOMMENDATIONS - Sustainable Irrigation Development in the White Volta Sub-Basin - page 221

9.2 R ECOMMENDATIONS
This study aimed at achieving an improved understanding of effective and
sustainable irrigation development in the White Volta sub-basin. However
there are other challenges to sustainable irrigation development which have
not been captured in this study. A typical example is the impact of climate
change on future water availability for irrigation and other competitive water
uses in the sub-basin. Another scenario is the impact of upscaling irrigation
development in Burkina Faso on competing water uses in downstream
Ghana. There are other possible future scenarios which can be studied
towards achieving sustainable irrigation development. There are also
institutional challenges identified in the study area. The transboundary
nature of the sub-basin demands effective collaboration and cooperation
between Ghana and Burkina Faso to ensure commitment in keeping each
other's needs into account. It is therefore recommended that future studies
be conducted on the above topics to help achieve sustainable irrigation
development in the White Volta sub-basin.
The study has not considered the possible future developments in other sub-
basins and the combined impacts of all upstream developments on the
Akosombo dam. To be able to assess the impact, the following needs to be
done: (1) to conduct analyses similar to the present in all other sub-basins;
and (2) to develop a dynamic water resources model to accurately assess the
impact. It is important to determine a ceiling above which upstream water
uses should not be permitted, not only to ensure sustainable hydropower
production but also to sustain riverine ecosystems and the associated
services. To achieve sustainable hydropower generation and irrigation
development simultaneously, objective criteria have to be developed, that are
derived from policies, with which maximum upstream abstraction levels can
be established, based on the data and models developed by this and other
studies. Setting maximum development levels is the mandate of the Volta
Basin Authority, but should be done in close collaboration with the Volta
River Authority and other key stakeholders in the Volta Basin.
9.3 L IMITATIONS OF THE S TUDY
The findings of this study have some limitations. A major drawback is the
lack of long-term streamflow measurements in the studied catchments, which
prevented the development of a hydrological rainfall-runoff model. Also the
interaction between surface water and groundwater in the sub-basin was
unknown making it impossible to adequately model this interaction in
WEAP.