Berlin: A Decentralized Approach to Sustainability
Susan Fitzgerald

Incentivizing Stormwater Management

Water companies in Berlin, like the rest of Germany, charge residential and commercial customers for stormwater removal based on the percentage of impervious surface on a property. In other words, customers are charged for the amount of water actually draining into the city's stormwater system. Not only is the system a fair way of distributing the cost of the city's stormwater system, the implementation of the fees raises public awareness about stormwater management and incentivizes conservation--customers are rewarded for small changes on their properties which can have a cumulative impact on the overall health of the city's watershed. The "greener" an individual property, the lower the stormwater fees assessed that property's owner.

Under the city's stormwater management fee system, customers are charged for the amount of water that actually enters the city's stormwater system. Therefore, parcels with large impervious surfaces, such as the parking lot above, are assessed larger fees than those with large amounts of green space.

 

Similar to the Green Area Ratio program, a weighted system of Best Management Practice technologies determine how a parcel's green area will impact fees assessed for stormwater management. The weight of the technology is multiplied by its area, then divided by overall parcel size.

Berlin's BMP technology weighting system.

 

 

Best Management Practices include green roofs and permeable pavers, left.

Targets

The stormwater fee system targets both new and older developments. In new development, implementation of BMPs can reduce the need for "gray" infrastructure, as a large percentage of stormwater runoff can be infiltrated on site, allowing utility companies to downsize or disconnect developments from their stormwater system. Moreover, the BMPs are common in Germany, easy to implement and largely cost effective (Keeley 2007).

In older developments, use of BMPs can lessen the stress on existing gray infrastructure, thereby delaying its obsolescence. BMPs can also help stop "creeping imperviousness" in developed areas.

Benefits

There are a number of benefits to Berlin's stormwater management system. First, it promotes low impact, environmentally friendly design while, simultaneously, allowing for dense development which does not alter the existing character of the city. The system also promotes public awareness of stormwater issues by giving them a financial interest in the overall health of the watershed. Finally, by assessing fees based on individual useage of the stormwater system (i.e., actual water volume entering the system from a given property), the program fairly addresses the city's high cost of stormwater management.

Costs

The costs for implementing the stormwater fee program were high--$11.5. This was attributed to several factors. First, there was no good data in existance regarding performance of the various BMPs. This needed to be ascertained in order to determine how they should be weighted. Consultants were retained to evaluate the technologies, as well as to determine the existing percentage of "green area" on each parcel throughout the city. Computers and software had to be purchased to aid in this evaluation. Moreover, a massive outreach campaign was undertaken in order to maintain transparency (the public was skeptical about the utility companies' motives for implementing a new fee structure) as well as to educate the public about how they could use BMPs to reduce their stormwater management fees (Keeley 2004, Keeley 2007).

 

Next: Evaluation of the Programs

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Green Urbanism and Ecological Infrastructure || Instructor, Jack Ahern

Department of Landscape Architecture and Regional Planning
University of Massachusetts, Amherst

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