Evaluating international development investments based on ecosystem services impact

Engineered water-control structures to supply water for agriculture are frequently funded by international development to an effort to improve human wellbeing. Dams, reservoirs, and other forms of water control frequently have negative impacts on other water users; however, their sustainability in the face of climate change and evolving watershed processes have been called into question. Increasingly, planning for and evaluation of investments in water control require integration of these larger scale impacts and dependencies. Ecosystem service approaches can use local to regional scale knowledge to integrate a broader scope of project impacts by quantifying trade-offs in multiple services across proposed development interventions and future scenarios (economic, climate, demographic). Here, we illustrate the role an ecosystem service approach can play in investment decision making to evaluate the impact of small reservoirs on human wellbeing in the Upper Volta Basin of West Africa. Our project has four components: (1) design of a spatially explicit regional-level social-ecological characterization; (2) construction of future scenario analyses for rainfed and irrigated production system interventions; (3) co-design and co-development of benefit sharing mechanisms at the reservoir catchment level and enhancing institutional capacity to implement these mechanisms through training, professional development and targeting tools; and (4) intervention decision analysis to identify benefits, costs and risks associated with decision options. We illustrate how this approach highlights different outcomes than standard cost-benefit analysis focused narrowly on the single project. Anticipated outcomes are development of ecosystem services-based methods for more equitably and sustainably evaluating development interventions and identifying management approaches to water-impoundment structures that promote a range of ecosystem services to provide food security to a broader population.