Abstract
Achieving sustainable development in the Anthropocene is particularly challenging in East African mountain region and requires urgent action. Watershed investments, aimed at securing water for cities, present a promising opportunity for large-scale sustainability transitions in the near future. When properly designed, these investments promote activities that enhance ecosystem services, protect nature and biodiversity, and support societal goals. In this paper, we build on the concepts of ecosystem services and boundary work, to develop and test an operative approach for designing and assessing the impact of watershed investments. The approach facilitates negotiations among stakeholders on two key components. 1) Strategic component: this includes setting the agenda; defining investment scenarios; and assessing the performance of watershed investments as well as planning for a follow-up. 2) Technical component: it concerns data processing; tailoring spatially explicit ecosystem service models; hence their application to design a set of “investment portfolios”, generate future land use scenarios, and model impacts on selected ecosystem services. A case study in the Eritrean highlands, focusing on the Asmara metropolitan area, illustrates how the technical component can be developed in a data-scarce context in sub-Saharan Africa. The case study addresses challenges related to soil erosion and water scarcity, with urban water security and rural poverty alleviation as key objectives over a ten-year planning horizon. The case study results include spatially explicit data (investment portfolio, land use scenario, impact on ecosystem services), which were aggregated to quantitatively assess the performance of different watershed investments scenarios. By addressing stakeholders' concerns of credibility, saliency, and legitimacy, our approach is expected to facilitate negotiation of objectives, definition of scenarios, and assessment of alternative watershed investments, ultimately, to contribute to implementing an adaptive watershed management.