Nummela 'GATEWAY' Wetland Park, Finland

National Id
Site name
Nummela, Municipality of Vihti, Uusimaa Region, Southern Finland
In 2010, the Nummela Gateway Wetland Park (2ha), Finland was constructed both as water environment mitigation landscapes and as urban park. Monitoring of the Nummela Gateway wetland park over a period of three years shows that constructed wetlands rapidly self-establish, resulting in an increase in biodiversity and the establishment of several ecosystem services (e.g. erosion and flood control, and reduction of pollutants in runoff water). The constructed wetland also provides a range of other benefits including opportunities for recreation and education.
RBD code
NWRM(s) implemented in the case study
Climate zone
cool temperate moist
Mean rainfall
Mean rainfall unit
Average temperature
Case Study Info
Light or indepth?
Monitoring impacts effects
Monitoring location
Catchment outlet
Monitoring parameters
continuous flow and water level , nutrients, conductivity, temperature, pH, oxygen, hydrocarbons, metals, bacteria
Monitoring upstream station
the monitoring is case study specific
Monitoring downstream station
the monitoring is case study specific
Performance impact estimation method
Edge of Field/Plot
Performance impact estimation information
Monitoring was performed to monitor impacts with regard to water quality and quantity, carbon content in soils, greenhouse gases, vegetation as well as evaluating ecosystem services.
Application scale
Installation date
Performance timescale
1 - 4 years
Area (ha)
Area subject to Land use change or Management/Practice change (ha)
Size unit
Peak flow rate
Public consultation
Contractural arrangements
Design contractual arrangement
Arrangement type Responsibility Role Comments Name
Contractual agreement
for LIFE+ project Urban Oasis
Th partnership agreement on implementation of the LIFE+ project
Design consultation activity
Activity stage Key issues Name Comments
Design land use change
Land use change type
Design authority
Authority type Role Responsibility Name Comments
Local water authority
Initiation of the measure
University of Helsinki
Initiation of the measure
Municipality of Vihti
The Water Protection Association of the River Vantaa and Helsinki Region
Uusimaa, Centre for Economic Development, Transport and the Environment
Regional Policy: Cohesion Funds, ERDF
Key lessons
1) importance of having monitoring to verify the benefits from the wetland construction;
2) importance of the partnership and engadegment of relevant stakeholders; collaboration between environmental, planning and technical authorities has been crucial
Success factor(s)
Success factor type Success factor role Comments
Attitude of relevant stakeholders
main factor

Participatory approaches and engagement of stakeholders in the design and implementation of the process were found beneficial to long-term success. Collaboration between environmental, planning and technical authorities has been crucial. In addition, the local association for water protection (VESY ry) has been an active partner in the project supporting several voluntary actions. The Uusimaa Centre for Economic Development, Transport and the Environment (UUDELY) has participated in project management and monitoring from the
beginning, providing guidance and support at the regional level. Appropriate technical expertise (e.g. sustainable landscape design and monitoring) has been secured by involving experts from the University of Helsinki, Luode Consulting Oy, UUDELY, and Water Protection Association of the River Vantaa and Helsinki Region. Finally, the Finnish
Association for Nature Conservation (SLL) has supported communication and environmental education activities.

Financing possibilities
main factor

Initially, the project was funded by municipality and regional development center. LIFE+ project was developed and is implemented 2012-2016 as follow up and expension with similar activities in the area

Conducted assessments (incl. economic)
main factor

Availability of the information on key ipacts and results from the activities

main factor

The project combines environmental (water pollution, habitat degradation, etc.) and social aspects (recreation)

Financing type Comments
Sub-national funds
regional authority of the Uusimaa Centre for Economic
Development, Transport and the Environment (UUDELY)
Local funds
Budegt of Vihti municipality
EU-funds: LIFE+
For follow up project called Urban Oasis
Barrier type Barrier role Comments
Driver type Driver role Comments
Organisation committed to it
To improve the situation, the existing unsustainable means of disposal of runoff water was examined at the watershed level, seeking solutions through a holistic assessment of watershed processes and dynamics. As a result, new wetlands were created along the heavily degraded stream corridor to compensate for land-use changes within the watershed and
to restore lost stream corridor habitats. In addition, a large wetland park named the Nummela Gateway Wetland Park was established at the mouth of the Kilsoi stream. The construction of wetlands was led by the project team and supported by a range of local and regional stakeholders.
Financing share
Financing share type Share Comments
National funds
municipality, initially
National funds
regional, initially
European funds
LIFE+ programme for project Urban Oasis
Policy description
1) due to land-use changes and inadeqaute urban waste water management the Lake Enäjärvi watershed have resulted in poor water quality and related adverse impacts such as increased algal blooms and fish mortality.
2) problems such as erosion, flooding, draught, habitat degradation and low water quality were common in the area, preventing local people from accessing and enjoying from their surrounding natural environment
Part of wider plan
Policy target
Target purpose
Pollutants Removal
Improved Biodiversity
Oher Societal Benefits
Runoff control
Peak-flow reduction
Policy pressure
Pressure directive Relevant pressure
Policy area
Policy area type Policy area focus Name Comments
Policy impact
Impact directive Relevant impact
Policy wider plan
Wider plan type Wider plan focus Name Comments
Vihti municipality plan
Local municipal plan reflects the change in zoning of land use.
Policy requirement directive
Requirement directive Specification
Costs total
Costs total information
The initial sum was used to restore the river channel and related wetlands, as well to establish
Ecosystem improved biodiversity
Information on Ecosystem improved biodiversity
These wetlands were constructed by excavation in abandoned crop fields. Vegetation was allowed to selfestablish. Seven vegetation zones were identified at the Gateway wetland: natural flood meadow by the lake, constructed islands, constructed wetland area, two dryer wet meadow areas, area of Salix shrubs, and adjacent forest edge. Annual monitoring for species and foliar coverage in summers of 2010, 2011 and 2012 (94 area 0.5m2 plots) revealed that the vegetation selfestablishment at the Gateway wetland was rapid, rich in taxa, and dominated by native wetland species. Only two alien species were identified: Elodea canadensis in deep water areas and Epilobium adenocaulon in dryer meadow areas. Coverage exceeded 90% in 2012.
Ecosystem impact climate regulation
Impact on GHGs (net emissions and storage) including soil carbon
Information on Ecosystem impact climate regulation
GHGs have been continuously monitored at the Gateway wetland by the eddy covariance method from air (measures fluxes) and directly from water (measures concentrations).
Measurements of GHG concentration in water during winter 2012-2013 indicate that the site has been a source of CO2 and CH4 into the atmosphere. However, ice cover has prevented 4
GHG emissions. The GHG concentrations in the water were sensitive to changes in flow rates. Polluted spills within the urbanized areas impacted water quality as well as GHGs released from the water at the wetland.
Peak flow rate reduction
Peak flow rate reduction unit
Ecosystem erosion control
Water quality overall improvements
Positive impact-WQ improvement
Information on Water quality overall improvements
Wetland decrease the risk of eutrofication in Lake Enäjärvi.
Water quality Improvements Phosphorus (P)
Water quality Improvements (P) unit
% reduction pf pollutant
Information on Water quality Improvements (P)
Wetland retained phosphorus comparatively most efficiently in July, but terms of terms of absolute quantity in October – November.
Water quality Improvements Total Suspended Solid (TSS)
Water quality Improvements (TSS) unit
% reduction pf pollutant
Water quality Improvements (TSS)
Monitoring data from late April 2012 show two peaks of suspended sediments following two rain events. In both cases the wetland reduced sediment load into the lake (by 24% and 12%, respectively)


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