Financing

The stormwater fee is determined based on the intended use and area of the zoning unit as specified in the local detailed plan; for apartment buildings, the floor area of the buildings is also taken into account when determining the fees. The area of a zoning unit refers to the area of a plot or an undivided, parcel-shaped plot.

The stormwater fee is collected from the area served by the municipality’s stormwater system, which includes the areas covered by the local detailed plan. In addition to stormwater sewers, the stormwater system consists of culverts, open ditches, stormwater wells, and various stormwater management solutions such as depressions, detention basins, infiltration structures, flow control structures, wetlands, and filtration solutions. The municipal stormwater fee covers the costs incurred by the municipality for stormwater management.

The Committee for Urban Environment and Infrastructure decides on the criteria for determining the stormwater fee and its amount, which are updated as needed.

Five fee categories

The stormwater fee has five different fee categories. Fee category 1 covers single-family homes, fee category 2 covers row houses and terraced houses, fee category 3 covers service and administrative buildings, fee category 4 covers apartment buildings and loft buildings, and fee category 5 covers commercial and industrial buildings as well as parking areas.

Maximum amounts have been set for stormwater fees in the different fee categories to ensure that the fees do not become unreasonably high for properties. In the highest fee category (Category 5), property owners may apply for a reduction in the stormwater fee if the specified conditions specified are met. The detailed determination of the fee categories and the calculation formula for the stormwater fee are presented in the stormwater fee document.

It was not possible to take all the specific characteristics of properties into account in the criteria for determining the fee, as this would have made the fee too complex and billing costs would have risen unreasonably. The criteria for determining the fee were obtained from the municipal register.

Collection of the fee

The invoice is addressed to the property owner or the holder of a city-leased plot within the stormwater system area.

At present, implementation is carried out on a project-based basis. Funding can be integrated into the budget once key constraints and viable solutions have been identified. In such cases, resources for implementation can be systematically incorporated into the broader budget strategy.

However, with a project based approach, financing for NBS operation, maintenance, and monitoring remains unclear, with no formal agreement on responsibilities or the extent of cost allocation between stakeholders. As a result, no dedicated financial mechanism or budget line has been established to cover these ongoing expenses.

This raises the question of introducing a stormwater fee, which has not yet been implemented. Clear delineation of responsibilities, identification of sustainable funding mechanisms, and the establishment of a dedicated budget line are therefore required to ensure long-term financial viability.