Integrated Economic-Hydrologic Assessment of Water Management Options for Regulated Wetlands Under Conditions of Climate Change: A Case Study from the Spreewald (Germany)

This paper presents an integrated economic-hydrologic approach for the assessment of water management options for wetlands. It is based on a water resources modelling framework for long-term basin planning, that is augmented to model ecosystem service provision levels of wetlands as a function of water availability and water management. The approach is applied to a case study of the Spreewald wetland that is major fen wetland in the mid-reaches of the River Spree (Germany). Different management options at the wetland and basin scale are assessed in a cost-benefit analytical framework regarding their performance under projections of future climatic conditions. The cost-benefit analysis is based on the valuation of important wetland ecosystem services: grassland fodder production, recreational boating, habitat and biodiversity conservation and regulation of greenhouse gas emissions. It is found that under future climatic conditions, regulated and drained wetlands such as the Spreewald will require an increasing amount of water to maintain the current levels of benefits derived from the wetlands ecosystem services. Additional inter-basin water transfer could compensate some of the negative effects of increased water demand. However, the assessed transfer option is not economically efficient. Water management approaches that increase the intra-annual water storage in the wetland soils by higher groundwater level regulation targets are found to generate net gains in benefits compared to the current water management without any increase of the water supply.