Despite challenges in many river basins, overall the planet has enough water to meet the full range of peoples’ and ecosystems’ needs for the foreseeable future, but equity will only be achieved through judicious and creative management.

Numerous pilot studies and case studies in the Volta Basin have evaluated practices, methods, and tools that could prove beneficial to others, both within the basin and outside of it. However, the question whether an intervention successfully applied in one location has a reasonable chance of success at any other location remains extremely difficult to answer.

A consistent finding in pilot studies is that detailed characteristics of the study locations economic, biophysical, institutional, and cultural characteristics can all play an essential role in the eventual success, and failure of achieving a successful outcome. For out-scaling of initiatives it is impractical to collect detailed information at every potential site where an agricultural land and water management (AWM) intervention might be introduced.

This project starts with the premise that, while certainty is unobtainable, degrees of certainty are both obtainable, using available information in a systematic way, and useful. The work builds on promising developments under the Challenge Programme round 1 that sought to combine available information using Bayesian statistics to answer questions about targeting and scaling out.

The CPWF Project V1, Targeting and Scaling Out, developed an evidence and knowledge-based tool (called TAGMI) that maps the likelihood that a given intervention will be successful in given locations. The tool is intended for non-expert users and is available via the World Wide Web.

The V1 project contributed to achieving the BDC challenge of improving rainwater and small reservoir management to contribute to poverty reduction and improved livelihoods resilience by producing a framework and web-based and electronic “decision support”, (or targeting and scaling out tool) that identifies likely sites to introduce AWM interventions for smallholder farming systems.

The research partnership of V1 involved Stockholm Environment Institute (SEI), Institut National de l’Environnement et de Recherche Agricole (INERA), University of Ouagadaougou, Kwame Nkrumah University of Science and Technology (KNUST) and Savanna Agricultural Research Institute (SARI).

The project was carried out in close collaboration with CPWF Volta basin projects V2, V3, V4 and V5, and with CPWF Limpopo (L1).