National Id
Finland_01
Site name
Kylmäojankorpi
Summary
The Kylmäojankorpi case study represents research work where water quality (dissolved oxygen, electrical conductivity, turbidity, and temperature) and stream-stage measured continuously. The existing forest wetland (c.a. 11ha), Kylmäojankorpi, is located in Vantaa city which is neighboring the capital city Helsinki. The study results show that forested wetland improves and regulates stream water quality and flow regime. The obtained knowledge can be used to estimate environmental effects from the similar type of forested wetlands in urban areas.
Light or indepth?
In-depth
The in-depth description of the case study
cs-fi-01-final_version.pdf
NUTS Code
Helsinki-Uusimaa
RBD code
FIVHA2
Transboundary
0
Data provider
Kristina Veidemane, BEF
Source(s)
The regulation of stream water quality and flow by a forested wetland, Kylmäojankorpi, Vantaa.
NWRM(s) implemented in the case study
Urban forest parks
Basins and ponds
Wetland restoration and management
Longitude
25.036
Latitude
60.33989
Climate zone
cool temperate moist
Mean rainfall
650
Mean rainfall unit
mm/year
Average temperature
4,90000009536743
Mean runoff unit
450 - 600 mm
Average runoff coefficient
0,200000002980232
Type
Case Study Info
Water quality inflow
2
Water quality inflow unit
mg/L
Mean annual runoff range
150 - 300 mm
Average slope range
nearly level (0-1%)
Vegetation class
Site surrounded by discontinuous urban fabric (112) and industrial or commercial units (121); actual site is 100% covered by vegetation (tree canopy and ground vegetation)
Monitoring impacts effects
1
Performance impact estimation method
Catchment outlet
Performance impact estimation information
The case study represents a research project where water quality (dissolved oxygen, electrical conductivity, turbidity, and temperature) and stream-stage measured continuously. Intermittent water samples for chemical and biochemical analysis were also taken during base flow and rainfall events for more detailed study of wetland impacts on water quality and export loads of solutes.
Application scale
Field Scale
Area (ha)
11,3000001907349
Area subject to Land use change or Management/Practice change (ha)
37,2999992370605
Size
37,2999992370605
Size unit
ha
Constraints
This is a protected area to maintain a semi-natural forest and wetland in an urbanizing landscape. The main factors influencing site selection are thus pre-existing flow paths and historical land use.
Inflow volume
0,0149999996647239
Inflow volume unit
m3/sec
Outflow volume
0,00700000021606684
Outflow volume unit
m3/sec
Peak flow rate
0,0299999993294477
Public consultation
0
Contractural arrangements
0
Design contractual arrangement
Arrangement type Responsibility Role Comments Name
Site protected in 2000 (given conservation area status).
The study of the water quality and flow regime was conducted within the MSc programme of the HELSINKI University
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
Other
Implementation
Vantaa City
In charge of spatial planning in the area
Forest owners
Other
Vantaa and Helsinki Parish Church Council
Regional / sub-national water authority
Monitoring
Water Protection Association of the River Vantaa and Helsinki Region
Regional / sub-national water authority
Other
Finnish Government,
Uusimaa Centre for Economic Development, Transport and the Environment (ELY)
Regulatory framework for wetland protection
University of Helsinki
Conducted the study to assess effectiveness of wetland for NWRM and pollutant attenuation
Key lessons
The Kylmäojankorpi case study represents a research work which aimed to assess whether and how existing forested wetland improves and regulates stream water quality and flow.
Financing mechanism
0
Success factor(s)
Success factor type Success factor role Comments

Not relevant
Financing
Financing type Comments
Other
The main purpose was to retain a semi-natural forest in a rapidly urbanizing suburb of Helsinki.
Barrier
Barrier type Barrier role Comments
Not relevant
Driver
Driver type Driver role Comments
Not relevant
Financing share
Financing share type Share Comments
Policy description
The study monitored a forest wetland, Kylmäojankorpi, in Vantaa city. Because of the large amount of land sealing surrounding the wetland, there are potential problems with flashy runoff and water quality.
Part of wider plan
0
Policy target
Target purpose
Peak-flow reduction
Runoff control
Pollutants Removal
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
Policy requirement directive
Requirement directive Specification
Direct benefits information
The economic benefits from maintaining forest wetland in urban areas have not been estimated.
Costs investment information
this is not relevant
Costs operation maintenance
this is not relevant
Costs total information
this is not relevant
Ecosystem improved biodiversity
1
Information on Ecosystem improved biodiversity
The protected area and wetland complex will provide more natural habitat and may contribute to meeting Habitats Directive requirements.
Ecosystem provisioning services
0
Ecosystem water supply
0
Ecosystem impact climate regulation
No information available
Runoff reduction
38
Runoff reduction unit
% Percent
Information on runoff reduction
Stream discharge (Jun †“Aug 2010) decreased, i.e. reduced runoff and risk of flooding downstream, which is housing areas
Peak flow rate reduction
47
Peak flow rate reduction unit
%
Information on Peak flow rate reduction
Mean peak flows (6 rainfall events, Jul-Aug 2010) reduced
Information on Ecosystem flood control volume
Risk of flooding downstream reduced
Water quality overall improvements
Positive impact-WQ improvement
Water quality Improvements Phosphorus (P)
54
Water quality Improvements (P) unit
ppm
Water quality Improvements Nitrogen (N)
1,70000004768372
Wq Improvements n unit
mg/L
Water quality Improvements Total Suspended Solid (TSS)
5
Water quality Improvements (TSS) unit
mg/L
Water quality Improvements Copper (Cu)
2,29999995231628
Water quality Improvements (Cu) unit
ppm
Water quality Improvements Zinc (Zn)
10,3000001907349
Water quality Improvements (Zn) unit
ppm
Water quality Improvements Escherichia Coli (e.coli)
296
Water quality Improvements (e.coli) unit
cfu
Soil quality overall soil improvements
Neutral impact-no change in SQ status