The Emscher Region and Berlin: Lessons in Stormwater Management

In its efforts to promote green infrastructure, EPA has funded papers to promote international dialogue and learning on the issue. Two of them have been recently published and I’m going to provide summaries on both of them to give a quick overview for the benefit of my own understanding and hopefully to spur some interest from ridiculously busy professionals in the field.

The papers start by recognizing the wide promulgation of low impact practices Germany has achieved in the last 40 years for stormwater management. The series of papers then studies similar cases there and in the U.S., and builds a framework to allow lessons from Germany to be adapted to the specific conditions present in the U.S.

The first paper of the series, The German Experience in Managing Stormwater with Green Infrastructure by Nickel et. al., is based around the cases of the Emscher Region in Western Germany and Berlin. Both cases share similarities to areas in the upper Midwestern United States that have experienced loss of population and industrial base and are trying to transition to a post-industrial economy while tackling water quality problems with seriously constrained budgets. The below is a very rough sketch of the cases laid out by the authors.

The Emscher Region has serious water quality problems due to legacy pollution from the regions heavy industrial base and coal mining as well as flooding problems from unmanaged stormwater from development. Public leaders have begun an effort to cope with these problems by restoring natural surface hydrology. The effort began with pilot and grant programs to build support for green practices which were then followed by a comprehensive strategy to link up small projects with regional goals. Public leaders had a financial incentive to make the strategy work as an analysis showed that a 15% reduction of impervious cover would allow for the dimensions of the sewer system to be reduced, resulting in a savings of €270 million (approximately $350 million). The estimated costs in green infrastructure investments to achieve these savings are €250 million.

Regional stakeholders were able to agree to reductions of 1% in impervious cover per year in order to achieve the 15% reduction by 2020. As of 2010, stakeholders were slightly behind the goal but have plans to achieve a 7.5% reduction of impervious cover by 2013.

Berlin, my home come September, has had a rather unique relationship with its water resources. For a good portion of the last century Western Berlin was an island and had to depend on groundwater from within its city limits. The political situation also created a demand for green recreational spaces within the city, placing a further emphasis on self sufficiency, an emphasis that was maintained even when it was no longer necessary.

Berlin’s municipal resources were strained with the fall of the Wall as predicted population growth did not materialize and revenues dropped from the loss of water intensive industries. Under these conditions the city looked for cost effective green infrastructure practices to meet its goals. Where the city could afford to, it provided direct subsidies to reduce impervious cover and increase green space and compulsory guidelines were introduced for public buildings. On top of the highest stormwater fees in Germany, Berlin has also introduced the Green Area Ratio, a planning requirement for private developers which afforded them significant flexibility in meeting municipal environmental goals by awarding them points for various practices. For example, a fully impervious surface will be awarded 0 points while vegetation connected to the soil will be awarded 1 point and a green roof will be awarded .7 points. The flexibility embodied in the practice has received positive feedback from architects and the practice has now been incorporated in Washington, D.C. and Seattle.

The authors believe both Berlin and the Emscher region demonstrate the importance of integrated environmental planning. They do a good job laying out all the different components that need to be in place for this to happen effectively. Stakeholder groups need a chance to iron out competing priorities so that benefits can be optimized and costs minimized. Usually this process has to be guided by determined public leadership. Strong and clear communication between stakeholders is also particularly crucial so that implementation of decentralized practices is effectively coordinated and extensive guidelines on best management practices is crucial. Framework policies that allow decentralized stakeholders to adjust to local conditions while still advancing common goals are also important and the authors emphasize the Emscher regions goal of 15% reduction in impervious cover in 15 years as exemplary. I would like to add that the Green Area Ratio is also a good example of such a policy even though it does not provide as clear a vision of overarching management goals. Finally proper incentives and fees are all necessary to signal various groups of the direction they should move in.

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