Regional water system analysis: System dynamics modelling for case studies Woumen & Mechelen

In the B-Watersmart Living Lab Vlaanderen effects of innovative technological measures on the regional water system are studied. In this report, we used a system dynamics model to identify these effects. A system dynamics model can be used to investigate interactions and feedbacks between different subsystems. In the B-watersmart Living Lab Vlaanderen, two case studies with different landscape characteristics and challenges in the water system are defined, where measures are implemented. In the case study Woumen/De Blankaart an extra purification step is added to the drinking water production to deal with fluctuations in the water quality of the surface water (mainly chloride concentration) and to be able to use effluent from a waste water treatment plant (WWTP) as a source for drinking water production. In the case study Mechelen a stormwater retention basin is build to store urban runoff and re-use it for subirrigation in surrounding agricultural fields. The general research question for both case studies is: What is the effect of the measure on the regional water system in normal and dry periods and how does the measure affect the water-smartness of the water system?

In this report we modelled the water system for the two case studies with a specific system dynamic model for each region. We build the models with the software Vensim (https://vensim.com/). In both case studies project partners are performing pilots and technical modelling of subsystems, mainly at small scale and isolated from the regional water system. We explored the effects of the proposed measures on the regional water system and other water users in the region with the system dynamics model.