National Id
Netherlands_03
Site name
Leidsche Rijn, Utrecht
Summary
This scheme is currently under development as part of a large residential scheme at Leidsche Rijn, near Utrecht in the Netherlands. The scheme is ambitious in terms of its water management and extensive use of SuDS. It aims to prevent discharges from the site as far as possible (through storage and infiltration) as well as to reduce inputs of poor-quality water from elsewhere. Management of existing and new water bodies on the site will be integral to the scheme, providing improved ecology and recreational opportunities. The time scale for development was expected to be 15-20 years, but due to the economic crisis the overall timescale has increased. A vertical reedbed test site has already been implemented within the site, which some data are available for, although that forms only part of the overall scheme.
Light or indepth?
Light
Location description
The site, Leidsche Rijn, is located on the outskirts of Utrecht, in the Netherlands.
NUTS Code
Utrecht
RBD code
NLRN
Transboundary
0
Data provider
Heather Williams and Dilian Jansen, AMEC
Source(s)
Nieuwe stad, schoon water
Voorbereiding praktijkonderzoek verticaal doorstroomd hylofytenfilter
NWRM(s) implemented in the case study
Permeable surfaces
Swales
Filter Strips
Soakaways
Detention Basins
Retention Ponds
Infiltration basins
Longitude
5.0522518
Latitude
52.0964879
Climate zone
cool temperate moist
Mean rainfall
850
Mean rainfall unit
mm/year
Average temperature
10
Mean runoff
765
Mean runoff unit
450 - 600 mm
Average runoff coefficient
0,899999976158142
Type
Case Study Info
Groundwater level
-1,75
Average slope range
1-2%
Vegetation class
grass turf, dryland grasses
Monitoring impacts effects
0
Performance impact estimation method
Unknown
Application scale
Field Scale
Performance timescale
> 20 years
Area (ha)
2400
Size
146
Size unit
ha
Design capacity description
The test reedbed that has already been installed at the site has the capacity to infiltration filter 2,2 million m3/year and 50% removal of suspended solids
Basis of design
2-year storm
Design contractual arrangement
Arrangement type Responsibility Role Comments Name
Design consultation activity
Activity stage Key issues Name Comments
n/a
Design land use change
Land use change type
Design authority
Authority type Role Responsibility Name Comments
Local water authority
Monitoring
HDSR
Other
Other
Gemeente Utrecht
Communal authority responsible for collection of storm water and other urban water in Vleuten-De Meern district
Other
Financing
Gemeente Vleuten-De Meern
Communal authority responsible for collection of storm water and other urban water in Vleuten-De Meern district
Other
Other
Provincie Utrecht
Regional authority (Province) responsible for natura 2000 and spatial planning
Key lessons
Integration of NWRM in a developing area is only possible in coordination with many parties, in particular to achieve the ambitious goal of an independently operating (self-sustaining) water system. The water system was designed as an integral part of the overall masterplan, and was considered from a very early stage in development.
Success factor(s)
Success factor type Success factor role Comments
Attitude of relevant stakeholders
main factor

There should be a shared desire to create a sustainable water system in an area to be developed
Financing
Financing type Comments
Local funds
budget of local authorities
EU-funds: LIFE+
pilot study in 2009 through LIFE
Barrier
Barrier type Barrier role Comments
Lacking coordination between authorities
secondary barrier
A lot of authorities are involved, over a long time period
Lacking financing sources
secondary barrier
Delays to implementation of the entire residential development have occurred as a result of the economic climate
Driver
Driver type Driver role Comments
Balancing different objectives
main driver
Development of a sustainable water system with recreation and ecological goals
Financing share
Financing share type Share Comments
Policy description
By keeping storm water in the Lijdsche Rijn area (through storage and infiltration), the communal waste water sytem and treatmentplant will be relieved. Emissions to surface water will be reduced
Quantified objectives
Less than 0,15 mg/l P (phosphate) in watersystem
Part of wider plan
1
Policy target
Target purpose
Groundwater Recharge
Runoff control
Peak-flow reduction
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
Masterplan Leidsche Rijn
Policy requirement directive
Requirement directive Specification
Direct benefits information
Reduced requirements for sewer system and waste water treatment capacity
Ancillary benefits information
Potential for recreational activities in the water courses that will be created (e.g. canoeing and ice skating)
Costs investment information
Costs of the water management aspects of the project not quantified (incorporated with overall development)
Costs operation maintenance
Costs of the water management aspects of the project not quantified (incorporated with overall development)
Costs total information
Costs of the water management aspects of the project not quantified (incorporated with overall development)
Ecosystem improved biodiversity
1
Information on Ecosystem improved biodiversity
Biodiversity will be improved through improved water quality in surface water courses.

In the scheme as a whole, many new water features, including channels and lakes, will be created to provide maximum biodiversity opportinites, taking account of the requirements of target species.
Ecosystem provisioning services
0
Information on Ecosystem provisioning services
N/A info
Ecosystem water supply
1
Information on Ecosystem water supply
Increased infiltration to groundwater
Ecosystem impact climate regulation
Reduced energy use (farm operations)
Information on Ecosystem impact climate regulation
In overall scheme, there will be a probable reduction in pumping requirements compared to the existing agricultural water management system.
Retained water
2200000
Retained water unit
m3/year
Increased water storage
1000
Increased water storage unit
m3/ha
Water quality overall improvements
Positive impact-WQ improvement
Information on Water quality overall improvements
A test vertical infiltration reedbed was installed at the site, with larger reedbeds now being installed as part of the main development. Improvements to water quality were seen from the test reedbed.
Water quality Improvements Phosphorus (P)
80
Water quality Improvements (P) unit
% reduction pf pollutant
Information on Water quality Improvements (P)
80% reduction in P seen from the test reedbed
Water quality Improvements Total Suspended Solid (TSS)
50
Water quality Improvements (TSS) unit
% reduction pf pollutant
Water quality Improvements (TSS)
50% reduction in TSS seen from the test reedbed.
Soil quality overall soil improvements
N/A info
Information on Soil quality overall soil improvements
N/A info