Stormwater fee - Hamburg

The city of Hamburg in Germany introduced a stormwater fee in 2012 to provide an incentive for restoring ecosystems to provide more permeable surfaces, such as green roofs, and to recover some of its costs for sewage network renewal and wastewater management. More specifically, the city invests ca. €60 million per year for sewage network renewal and has spent ca. €263 million on wastewater management. Of this, 29.3% are costs for stormwater management and 70.7% are costs for sewage drainage and treatment. In practice, the stormwater fee works by charging a sliding fee according to the impermeable area of a property and the degree to which the property is connected to the sewage network. The Hamburg Department of Stormwater Management set up a common Hamburg-wide GIS-system integrating all the map data on individual properties necessary for stormwater planning and for computing the stormwtaer fee. The fee is embedded in a mix of mutually supporting instruments for stormwater management, on private and public property.

Overview

Type of instrument:

Economic and fiscal instruments›Disincentives (e.g. taxes to change behavior, access fees, payments)

Challenges addressed

Water management (e.g. reuse)
Green space management (e.g. accessibility)
Watershed restoration/water quality
Flood risk: pluvial and fluvial / soil permeability

Consideration of nature-based solutions:

The stormwater fee is based on an integrated GIS platform containing an infiltration potential map; potential areas map for stormwater infiltration; decoupling potential map; water resource potential map; flood hazard and damage potential maps; emission potential map. The stormwater fee is based on identification of sealed surfaces in the infiltration potential map, complementing other instruments that use the other maps for targeting e.g. the use of nature-based measures, such as green roofs.

Targeted (peri-)urban areas:

Urban green space connected to grey infrastructure

Other

Good practice characteristics:

Effective

Support multifunctional NBS

Sustainable in the long-term

Locally appropriate

Potential to be replicated / upscaled

Innovative

Policy business case

Governance

Government body/bodies

Initiating body:

Hamburg City Council

Instrument design:

Details about how the instrument was designed:

The state owned utility company Hamburg Wasser initiated the cost-recovery wastewater charge with permission from its board of governors and participating municipal boards. The management of stormwater has been historically fragmented, shared between the State Ministry for the Environment and Energy in charge of managing water resources; local level districts with operational responsibility and planning and permitting; the State Ministry of Economic, Transport and Innovation in charge or major roads, and infrastructure measures carried out by the State Office for Roads, Bridges and Water Bodies. Hamburg Wasser and the State Ministry for Environment and Energy initiated the ‘Rain InfraStructure Adaption’ (RISA) project in order to coordinate all these actors to reduce fragmentation of stormwater management. One outcome of RISA was to address the lacking funding for stormwater management measures through a stormwater runoff fee. Actors were organised through 4 co-planning working groups charged with (i) urban drainage (ii) urban and spatial planning (iii) traffic planning and (iv) river basin management. The Department of Stormwater Management set up a common Hamburg-wide GIS-system integrating all the map data on individual properties necessary for stormwater planning and for computing the stormwtaer fee. Property owners were consulted on the outcome of the permeability mapping of their respective properties, and could return corrections through a posted data entry form.

Involvement of non-governmental actors:

Private sector, corporate, business

Researchers, university

Property owners

Type of actor involvement:

Co-planning or co-design of instrument (e.g. boards, advisory role)

Expert task force consultation

Civil society consultation through e.g. workshops, surveys

Instrument implementation:

Type of involvement:

The RISA GIS database based on remote sensing and registration data was supplemented by a comprehensive data survey to property owners. Property owners were consulted on the outcome of the permeability mapping of their respective properties based on aereal phtogrphy. Owners could return corrections through a posted data entry form. Owners could report back on whether property area was sealed, on green/conventional roofs, and the state of their drainage connections to sewers. On the basis of this owner-validated information the stormwater fee is calculated.

Type of non-governmental actors involved:

Citizen monitoring and review

Private property owners including households

Targeted actors:

Private: household, real estate developer, business , financial

Financing

Sources of funding:

Public local authority’s budget

Budget:

Above 10 000 000€

Details about instrument financing:

The stormwater charge was implemented in addition to a wastewater charge to recover costs of drainage and treatment. The sewage charge is based on a cost recovery principle and amounted to €2.11/m3, estimated based on drinking water supply volume. This compares to the stormwater charge aimed at cost recovery of €0.73/m2 sealed area per year.

Monitoring, evaluation and impacts

Is a monitoring framework in place?:

Yes

The RISA project establised a GIS database with information on the surface drainage situation of each property in Hamburg, which can be updated with orthophotos. The project generated data that can be validated by a household data survey. Key aspects that can be monitored include the factors determining the fee, namely the amount of property area that is impermeable or semi-permeable, the presence f green/conventional roofs, and whether drainage is connected to the sewage network.

Achieved outcomes and impacts:

Design of the stormwater fee, based on the RISA project, is able to provide sustainable funding for cost recovery of stormwater management measures needed in the future in Hamburg. The work with the fee and underlying data unlocked synergies across municipal agencies. It has also built up a GIS database which is useful for all stakeholders involved in stormwater management for scale-independent analyses on micro or on macro-scale. for other purposes than the fee. While the main objective of the stormwater fee is financial sustainability of investment and maintenance, there is no data in the sources used on the extent to which the stormwater fee has incentivized conversion on private property to permeable surfaces, green roofs or disconnection of private properties' drainage from the sewage network.

Success factors and lessons learned:

Success factors include being an integrated planning project with a matrix structure covering concerned departments, with collaboration with university research and private companies. To facilitate fee design and implementation, economic and legal topics were integrated into technical responsibilities of the Department for Stormwater Management. However, there was limited political follow-up action during the RISA project 2009-2014 (as reported in 2017 by Bertram et al). The authors argue that this may have been because the stakeholders focused very much on technical results and that the RISA project missed the active support and collaboration with policy-makers during the project’s duration.

Sources and further information

References

List of references:

Bertram, N.P., Waldhoff, A., Bischoff, G., Ziegler, J., Meinzinger, F., Skambraks, A.-K., 2017. Synergistic benefits between stormwater management measures and a new pricing system for stormwater in the City of Hamburg. Water Science and Technology 76, 1523–1534. https://doi.org/10.2166/wst.2017.337

Urban Nature Atlas case study of the RISA project: https://una.city/nbs/hamburg/risa-rainwater-infrastructure-adaptation-hamburg;

RISA Structure Plan Stormwater 2030. HSE/BUE (2015) Strukturplan Regenwasser 2030 – Ergebnisbericht des Projektes RISA (RegenInfraStrukturAnpassung). Hamburger Stadtentwässerung AöR (HSE) und Behörde für Umwelt und Energie (BUE), Hamburg 2015.

Interview(s):

none