Stormwater fees supporting NBS for stormwater management

Nordic examples of how stormwater fees can support NBS:

In 2013, Denmark adopted wastewater fees (through ‘Lov om afgift av spildevand’) that can support NBS for stormwater management on municipal and private properties, by funding the hydraulic functions of the measures. The Utilities Secretariat is responsible for regulating water and wastewater fees and is tasked with assessing whether these rules are complied with in each project, thus whether the project can be supported by revenues from the fee.

In Finland, municipalities' water and wastewater units are covered by the water services (2001), the purpose of which is to ensure appropriate water supply and wastewater management with regard to health and the environment. The water and wastewater units' services are paid for through fees collected from the recipients / customers.

Since 2014, municipalities in Finland have been able to charge a stormwater fee in addition to the existing service fee for stormwater management. The fee is intended to cover the municipality's costs for diverting stormwater from properties, parks and roads outside sewage pipes, including planning of the stormwater system, and is anchored in the Land Use and the Building Act. The Act requires the municipality to organize necessary measures for stormwater management in the detailed plan areas, but at the same time allows them to introduce a separate earmarked stormwater fee to cover their expenses. The landowner is responsible for managing stormwater on their own property by infiltration and possibly discharge to the municipality's stormwater system or the water and wastewater sector's wastewater system. Many taxpayers are owners of properties located in areas with municipal stormwater systems. Unlike the water and sewerage fee, it is not a direct payment for the property receiving water and sewerage services from the municipal water and sewerage sector.

In Sweden, an amendment to the Water Services Act in 2006 resulted in that stormwater fees are to be separated from other water and wastewater fees. The stormwater fee shall reflect the use of the stormwater services and be set according to the "benefit" the user obtains from the service - and not the costs caused by the property's use of the service. This means that, for example, no account is taken of whether the user is located near or far from the stormwater facility. In practice, it is not easy to accurately separate the costs associated with stormwater and other wastewater. This must therefore be assessed based on the wastewater and factors such as whether property is connected to the municipal sewer network, the size of the of the plot and the proportion of impervious surfaces on the plot. In Sweden, municipalities are also allowed to charge a fee for the road owner's use of the stormwater services. The fee can take into account the amount of stormwater generated on the road and the treatment needs of the stormwater. (Seifert-Dähnn et al., 2022)