Stormwater charges
All appendices are in Finnish.
The Technical Committee has discussed the stormwater fee bases and the fees in its meeting on 22.4.2025(Tekltk 22.4.2025 §35).
The basis for the calculation of the stormwater fee is the tariff adopted on the basis of Article 103 n of the Regional Planning Act. The criteria for determining the stormwater charge are laid down in the stormwater tax. The stormwater charge for a property is determined on the basis of this charge. The charge applies to the area affected by the Siilinjärvi municipality’s stormwater system, including the municipality’s zoning plan areas and areas outside the zoning plan from which stormwater flows into the municipality’s system or from which the municipality has built a stormwater network/system.
In order to ensure a fair distribution of the stormwater charge on the basis of the cause, the charge is divided according to the use and size of the property and the drainage coefficients (units) have been defined accordingly. The drainage coefficients determine the charge for the property.
The formula for the property charge is = X × K × V , where
- X is the unit price of the stormwater fee (€35.50/year)
- K is a coefficient that takes into account the type/use of the property and the area of the property
- V is the reduction/increase coefficient
For an individual detached house, the coefficient K = 1, and from there the coefficient of conductivity (units) increases according to the use and size of the property.
Uses distinguish and compare the accumulation and transport of stormwater. Roofs and courtyards of high-rise buildings drain more and faster than those of small houses. Likewise, more and more quickly from industrial estates than from blocks of flats and terraced houses. For these reasons, there are categories of use:
- Detached houses/apartment houses and leisure properties
Includes unbuilt properties, properties used for public utility purposes (e.g. schools, kindergartens, hospitals, churches, museums, fire and rescue services, etc.) - Semi-detached house
- Apartment/townhouse properties
- Private industrial, commercial and parking buildings
(e.g. commercial buildings, office buildings, transport buildings, care buildings, meeting buildings, educational buildings, warehouses, agricultural buildings, industrial buildings)
Specifications for the use classification definition
- the use is defined as industrial/commercial if there is a single industrial/commercial building on the property, if the property has only residential buildings:
- the use is defined as a detached/ semi-detached house if the property does not contain any apartment blocks or terraced houses, but there are one or two detached houses or one semi-detached house
- the use is defined as a terraced/chain house if the property does not contain any apartment/townhouses but there is one terraced/chain house or if the single-family houses/apartment buildings on the property contain more than two dwellings
- the use is defined as a residential apartment building if there is a single residential apartment building on the property
The use of a zoning unit is interpreted according to the actual use of the plot, not the use of the unrealised zoning plan, e.g. an industrial block may contain detached houses. For such zoning units, case-by-case discretion may be used in determining the charge.
To ensure fair treatment of the tariff, the surface area of the property also affects the amount of stormwater, and hence the discharge factor and the amount of the charge.
Siilinjärvi municipality’s stormwater charges and charging criteria.