Sinking surface water and groundwater levels, parched fields, water extraction bans in Brandenburg, and burning forests. Climate change has arrived in the Berlin-Brandenburg region and its impact will only increase in the coming years. To combat this, sustainable water management concepts must be developed at the local level. 

One possibility is to treat and reuse wastewater directly at the point of origin. Decentralized solutions for wastewater treatment and reuse are not a new concept, but they’ve hardly been applied in Germany. To increase the acceptance of decentralized solutions, AKUT Umweltschutz Ingenieure Burkard und Partner and KWB began developing the DeWaResT project in 2020. The goal: a sustainable contribution to local water management via a novel constructed wetland and decentralized water reuse. 

The project will focus on developing and testing a new constructed wetland which combines compactness and efficiency via its vertical multi-layer design and integrated aerobic sludge stabilization. The new process will be tested on Lake Parstein on the Pehlitzwerder peninsula (UNESCO biosphere reserve Schorfheide-Chorin). At the seasonally operated campsite on the lake, deliberate overloading of the constructed wetland during the summer will be studied to determine the appropriate load limits and necessary regeneration times during the winter. The campsite’s location in the nature reserve requires the treated wastewater to meet very high discharge quality standards: bathing water quality should be achieved with a minimal spatial footprint. To do so, additional post-treatment will eliminate pathogens and anthropogenic trace substances such as pharmaceutical compounds. The reuse of the water for irrigation will also strengthen the resilience of forest and woodland areas against longer periods of drought. To meet these multifaceted requirements, the performance of the experimental wetland  and the purification process will be continuously optimized.    

DeWaResT will further improve constructed wetland development and optimization. The combination of constructed wetlands, advanced treatment and water reuse is an important contribution to help the aridity-plagued region of Berlin-Brandenburg adapt to climate change, a problem which will only become more important in the future. Additionally, the water reuse concept developed in the project can be transferred to other regions worldwide. 

Photos above by Iryna Dazhura for KWB