General
National Id
Norway_01
Site name
Fornebu
Light or indepth?
In-depth
The in-depth description of the case study
RBD code
NO5101
Transboundary
0
Data provider
Martyn Futter SLU
Source(s)
NWRM(s) implemented in the case study
Longitude
10.6229
Latitude
59.9019
Site information
Climate zone
cool temperate moist
Mean rainfall
778
Mean rainfall unit
mm/year
Average temperature
6
Mean evaportranspiration
200
Mean evaportranspiration unit
mm/year
Mean runoff
0,00256849313154817
Mean runoff unit
600 - 750 mm
Average imperviousness
40
Type
Actual Test Site
Average slope range
0-1%
Vegetation class
grass/turf
Monitoring maintenance
Design & implementations
Application scale
City
Performance timescale
Immediate
Area (ha)
340
Area subject to Land use change or Management/Practice change (ha)
340
Size unit
ha
Design capacity description
The systems were designed based flows expected with a 1 year return period for channels and a 20 year return period for detention ponds. The average runoff was based on estimates of daily summer rainfall between 1957 and 1995. The wet ponds had design criteria of 230 m3 per effective hectare.
Basis of design
The NWRM are deisgned to treat a range of events with return times ranging from 1 to 20 years. Design criteria are based on long-term average summer rainfall.
Constraints
Winter conditions, snow and ice are a challenge to the implmentation of sustainable urban drainage systems at Fornebu and other northern cities.
Favourable preconditions
Having a brownfield site and a governance environment favorable to sustainable multi use urban landscape were key factors in the success of Fornebu.
Crop rotation
none
Design contractual arrangement
| Arrangement type | Responsibility | Role | Comments | Name |
|---|
Design consultation activity
| Activity stage | Key issues | Name | Comments |
|---|
Design land use change
| Land use change type |
|---|
|
Discontinuous urban fabric
|
Design authority
| Authority type | Role | Responsibility | Name | Comments |
|---|---|---|---|---|
Lessons, risks, implications...
Key lessons
Success was dependent on communication between different levels of government and a clear vision for a sustainable, multi-use urban environment
Success factor(s)
| Success factor type | Success factor role | Comments |
|---|---|---|
|
Financing possibilities
|
||
|
Attitude of decision makers
|
||
|
Attitude of relevant stakeholders
|
Financing
| Financing type | Comments |
|---|---|
|
National funds
|
|
|
Local funds
|
Driver
| Driver type | Driver role | Comments |
|---|---|---|
|
Organisation committed to it
|
main driver
|
Financing share
| Financing share type | Share | Comments |
|---|
Policy, general governance and design targets
Policy target
| Target purpose |
|---|
|
Runoff control
|
|
Peak-flow reduction
|
|
Pollutants Removal
|
|
Oher Societal Benefits
|
|
Increase Water Storage
|
|
Groundwater Recharge
|
|
Improved Biodiversity
|
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 |
|---|
Socio-economic
Direct benefits information
The Fornebu brownfield redevelopment has clear direct benefits as it provides space for living, employment and recreation in a crowded urban area. The specific benefits of the NWRM in Fornebu are harder to quaknitfy as they cannot really be considered in themselves but must be seen as part of the complete redevelopment picture.
Ancillary benefits information
Key ancillary benefits include more living space and a sustainable multi use urban environment supporting recreation, residential and industrial land use.
Costs investment information
Total investment cost is not known
Costs land acquisition information
No land acquisition costs as land was already owned by Norwegian government
Costs operation maintenance
unknown
Costs total information
Total cost is not known
Ecosystem improved biodiversity
1
Information on Ecosystem improved biodiversity
more aquatic habitat and greenspace
Biophysical impacts
Information on retained water
The total retained volume of water is hard to assess as the Fornebu plan consists of multiple NWRM and Green Infrastrucutre measures
Increased water storage
230
Increased water storage unit
m3/ha
Information on runoff reduction
Large qualitiative reductions in runoff peaks could be expected
Information on Peak flow rate reduction
Large qualitative reductions in peak flow could be expected when compared to the old Fornebu airport
Ecosystem erosion control
0
Water quality overall improvements
Positive impact-WQ improvement
Information on Water quality overall improvements
based on mdeolling results and design criteria
Water quality Improvements Phosphorus (P)
60
Water quality Improvements (P) unit
% reduction pf pollutant
Water quality Improvements Nitrogen (N)
40
Wq Improvements n unit
% reduction pf pollutant
Water quality Improvements Total Suspended Solid (TSS)
80
Water quality Improvements (TSS) unit
% reduction pf pollutant
Water quality Improvements Copper (Cu)
65
Water quality Improvements (Cu) unit
% reduction pf pollutant
Water quality Improvements Zinc (Zn)
45
Water quality Improvements (Zn) unit
% reduction pf pollutant
Soil quality overall soil improvements
Positive impact-SQ improvement
Information on Soil quality overall soil improvements
improvements related mainly to brownfield cleanup and removal of 200000m3 contaminated soil
Information on Soil quality overall soil pollution
brownfield improvement included removal of contaminated soil, PAH, oil and deicing fluids were all problems