Integrating Energy and Water Management in a Low Mountain Region: A Project for Coupled Ecosystem Services

An interdisciplinary research project supported by the European Regional Development Fund focuses on developing energy infrastructure projects. These projects aim not only to enhance energy security but also to provide predictable ecosystem services related to high and low water protection, as well as drinking water production. The background of the project is the Lower Saxony region of the Upper Harz Mountains in Northern Germany, which in recent years has been characterised by severe flood events but also by previously unknown periods of low water and bottlenecks in the drinking water supply. At the same time, the existing dams and the underground infrastructure from former mining offer potential for the development of pumped storage capacities that could be used to stabilise the grid or to produce green hydrogen for the adjacent industrial regions. Given the target system: (1) Water quantity management (flood protection and low water elevation), (2) Drinking water production, (3) Energy storage and electricity generation, this paper describes how project alternatives are generated under the geological conditions of a low mountain range and its foothills. The target system for evaluating infrastructure alternatives at different locations should also include construction costs (4) and the associated consumption of natural resources (5), such as in the area of flora and fauna. Moreover, it analyses how these alternatives can be evaluated in the course of a collective decision-making process. Since the benefits arising are multi-dimensional and cannot simply be quantified and offset against one another using market data and net present value estimates, the decision-making process of the Analytical Hierarchy Process is used for the evaluation. Here, the structure of a given target system is used to evaluate a set of sufficiently defined and independent alternatives. The advantage of this procedure is that the weighting of the single target dimensions does not have to be determined exogenously but is carried out in the process of collective decision-making. Decision-makers are asked to make pairwise comparisons within the respective target dimension. A ranking of the alternatives can be determined from the combination of the previously recorded target weights and the evaluations of the alternatives within the respective target dimension. The knowledge gained in the project can be used very well for future real investment projects for several reasons. First, the weighting of the target structure can be made transparent with this method. It can be shown, for example, how the ranking of the alternatives changes when the weightings are changed. Secondly, due to its participatory aspects, this procedure can be used for communication, for example, in the course of citizen participation procedures.