Stormwater

The property owner is responsible for managing stormwater on their own property. The municipality is responsible for organising stormwater management as a whole in areas covered by a town plan, as well as for managing stormwater in public areas such as parks and streets.

Stormwater is managed in a planned area using stormwater drains and ditches. In areas where there is no stormwater sewer network, stormwater from plots is directed into ditches. Floodwater caused by the heaviest rainfall cannot be conducted by stormwater drains alone, but ditches, depressions and controlled flood areas are also needed. For example, roads and streets act as flood routes, and the municipality is responsible for their design and maintenance. Property owners also have a responsibility to prevent flood damage. Everyone has a duty to prevent or limit damage in the event of a flood threat.

Stormwater management for properties

Stormwater management must be taken into account already at the planning stage of a construction project. Stormwater must also be managed during construction, as stormwater during construction will pollute waterways if it is directed straight into the stormwater system.

Those planning a construction project must present the principles of stormwater management in the site plan for the building permit or in a separate stormwater plan. Further information on building permit guidelines can be found on the Building Control website.

Checklist for property stormwater issues

Ensure that rainwater is not directed into the sewer system.
Ensure that the ditch used for drainage remains open.
Ensure that surface runoff does not flow onto your neighbour’s property.
Keep the street clean so that rubbish on the street does not block the drains.
The surface levelling should slope away from the building wall.
If the soil and elevation conditions of the plot allow, clean roof water and water from vegetated areas must ALWAYS be absorbed on the property. This is important in groundwater areas.
The management and conducting of stormwater must be presented in the stormwater plan.
In groundwater areas, the surface structures of yards and parking areas used by motor vehicles must be asphalted or groundwater protected otherwise. Surface runoff water must be treated and drained in such a way that it does not pose a risk of soil or groundwater contamination.
In larger construction projects, such as apartment building areas, in groundwater areas, and the Päijänne Tunnel protection zone, oil separation wells are installed in the traffic and parking areas of yards.
Recommended methods for stormwater management include above-ground detention and infiltration structures in accordance with 27 § of the municipal building regulations.

Yard renovation and storm water drainage:

When renovating a yard, it is a good idea to organize the water management so that clean roof water is collected for irrigation.
Roof and surface runoff water is directed to vegetation areas, absorbed into suitable soil, or the running of water is slowed down with above-ground and underground systems. Ditches and depressions significantly slow down the flow peak into stormwater drains and prevent local flooding.
When renovating a yard, it is a good idea to minimize the amount of sealed and impermeable paved surface. Use permeable soils and avoid excessive compaction to maintain good infiltration capacity.
Managing stormwater with vegetation is desirable by implementing rain gardens and vegetated swales in areas where water naturally accumulates. Diverse, deep-rooted perennials, shrubs, and tress improve soil permeability and reduce and absorb surface runoff generated on the property. Regular maintenance of plantings is necessary so that they reduce flood risk, improve stormwater quality and increase the amenity of the yard.

Disputes concerning stormwater issues

The Building Control Division acts as the stormwater authority in Tuusula, resolving any disputes (boundaries between properties, etc.).

In case of disputes, please contact us by letter or email:
Tuusula Municipality/Building Control
PO Box 60
04301 Tuusula
Email address: rakennusvalvonta@tuusula.fi

Please note! For matters concerning stormwater in public areas (streets, parks), please contact municipal engineering planning.

General guidelines and legislation related to stormwater

General guidelines for design can be found in, for example, the Stormwater Guide (switch to another service)(Association of Finnish Local and Regional Authorities 2012) and RT cards. Design guidelines can be found, for example, in publication RT103006 STORMWATER STRUCTURES 11/2018, pages 25–28.

The following should be taken into account when planning stormwater management:

stormwater management guidelines specified in the environmental permit
municipal building regulations (especially 27 §)
municipal environmental protection regulations
possible planning regulations concerning stormwater.

The responsibility for organising stormwater management in areas covered by local detailed plans was transferred from water utilities to municipalities through a 2014 amendment to the Land Use and Building Act (132/1999) (Chapter 13a); these provisions are now incorporated into current land use legislation.

The most important laws relating to stormwater are:

Land Use Act (752/2023)
Construction Act (751/2023)
Water Services Act (119/2001)
Water Act (587/2011)
Act on Flood Risk Management (620/2010)
Act on Water Resources Management (1299/2004)
Environmental Protection Act (527/2014)
Nature Conservation Act (9/2023)
Act on the Maintenance and Cleaning of Streets and Certain Public Areas (669/1978)
Act on Transport Systems and Highways (503/2005)
Railway Act (110/2007)
Ministry of the Environment Decree on Water and Sewerage Systems in Buildings (also includes obligations related to stormwater)
Regulation (EU) 2024/1991 of the European Parliament and of the Council on nature restoration.

Connection of existing property to the stormwater drainage system

When a previously constructed property wishes to connect to the stormwater system in a town plan area, the water agreement must be updated with regard to stormwater on the Tuusulan Vesi website. For further information, please contact vesihuoltolaitos@tuusula.fi or call 040 314 3577.

Stormwater fee in the local detailed plan area from autumn 2026

From 2026, the municipality of Tuusula will collect a stormwater fee to cover the costs of stormwater management in the stormwater system area, i.e. the local detailed plan area. In this area, the municipality has built structures and equipment intended for stormwater management.

The fee consists of a basic fee (30 euros/year) and a property-specific portion, which is affected by the purpose of use, area and average amount of impervious surface of the property type. On certain grounds, relief or exemption from the fee is possible.

The stormwater fee is calculated by property type:

detached houses, semi-detached houses, single-family holiday homes 30–45 euros/year
terrace houses, connected detached houses, properties with several detached houses 96–960 euros/year
apartment buildings 108–1080 euros/year
commercial, office, industrial and workplace properties 198–1584 euros/year
public services, entertainment and accommodation use, service buildings and municipal technical maintenance areas 117–858 euros/year
parking areas 117–936 euros/year.

The stormwater fee is intended to be introduced so that it will be charged for the first time in autumn 2026 and in the future once a year during the autumn. The invoicing is based on the use and ownership or possession of the property on the first day of June (1.6.).

In addition to the stormwater fee, the Tuusula council made a decision in March 2026 on stormwater responsibilities in the municipality. While previously the municipality was responsible for ditches and culverts and the water utility Tuusulan Vesi for stormwater sewers, as of 1.4.2026 the municipality will have overall responsibility for stormwater management.

This content has been translated using AI