Location: Greater Nottingham, United Kingdom
City population: 643,933
Project duration: 2013 - 2015
Project cost: 50 000 - 100 000 EUR
Financing source(s): Public national budget, Public local authority's budget

Retrofit Rain Garden Project

Retrofit Rain Garden Project

Ribblesdale Road, Nottingham Retrofit Rain Gardens (SuDS) project. "The scheme was developed with the vision to encourage and support change locally in dealing with issues around the water environment. The pilot project aimed at achieving a deliverable project that could be assessed over time and draw together statutory authorities to learn about Sustainable Drainage Systems (SuDS) and evoke change." (Ref. 2)

Urban setting

  • Green areas for water management
    • Rain gardens
    • Sustainable urban drainage systems

Key challenges

  • Water management (SDG 6)
  • Green space, habitats and biodiversity (SDG 15)
  • Regeneration, land-use and urban development

Main beneficiaries

  • Local government/Municipality
  • Non-government organisation/Civil Society
  • Citizens or community groups
Project objectives
The pilot retrofit SuDS project was designed to achieve the following objectives; “Document and evaluate the design and construction of a series of rain gardens within an existing highway setting; Maximise surface water interception, attenuation and infiltration; Test the effectiveness of rain gardens in managing surface water from the public highway; Encourage participation from local residents in the design and future management of the rain gardens; Evaluate the effectiveness of the scheme as an engagement tool around the sources of urban diffuse pollution and flood risk; Highlight the role that retrofit SuDS can play in improving the quality and reducing the volume of surface water flowing to urban watercourses”. (Ref. 1)
Implementation activities
“A total of 21 linear rain gardens (total of 148m2) were constructed within the grass verge. The scheme was designed to manage surface water runoff and to always intercept and treat the, often more polluted, first flush of highway runoff. Existing highway gullies have been retained to allow for overflow when the rain gardens reach capacity. Budget constrains meant that the use of proprietary cells was reduced and replaced by stone fill in a number of gardens. It is hoped that differences in the performance of the 2 different rain garden designs will be evaluated over the coming years”. (Ref. 1) The primary principle was to ensure effectiveness in managing downstream water quality and flooding. As part of this, aesthetic benefits were an important consideration, to ensure no loss of the green areas already limited within the urban environment. Part of the purpose of this pilot study was to understand the public perception and acceptability of rain gardens. (Ref. 3)

Type of initiating organisation

  • National government
  • Local government / municipality
  • Non-government organization / civil society
  • Citizens or Community groups

Management set-up

Co-governance or hybrid governance (mix of responsibilities between government and non-government actors)

Participatory approaches/ community involvement

  • Co-planning
  • Taskforce groups
Details on the roles of the organisations involved in the project
The pilot retrofit SuDS project was a result of collaboration between the Environment Agency (Financial; guidance; evaluation), Nottingham City Council (Construction; design; maintenance), Groundwork Greater Nottingham (Design; implementation; community liaison) and Severn Trent Water (post construction modelling). The project was initiated by Environment Agency and Nottingham City Council. (Ref. 1, 3)
Project implemented in response to ...
... an EU policy or strategy? Yes
EU's Water Framework Directive (WFD); Reducing/mitigating flood risks (Floods Directive). (Ref. 3)
... a national policy or strategy? Unknown
... a local policy or strategy? Yes
“Urban diffuse pollution programme across the region.” (Ref. 3) ["Within the highly urbanised area of Nottingham City, a total of 972 properties fall within the Day Brook floodplain, with previous fluvial events leading to property flooding downstream. Ribblesdale Road is parallel to some of the upper reaches of Day Brook, a heavily modified watercourse that has poor water quality due in part to numerous sources of diffuse pollution from the extensive urban catchment."] (Ref. 3)
Expected impacts
  • Water management (SDG 6)
  • Green space, habitats and biodiversity (SDG 15)
  • Regeneration, land-use and urban development
Details on impacts and indicators used Monitoring: Data logger installed beneath two of the rain gardens, which allows continuous water depth recording. (Ref. 3) Initial results from the InfoWorks CS 2D model of the scheme suggests a 33% reduction in the flow reaching the sewer during a 1 in 1 return period storm. (Ref. 1) A total of 21 linear rain gardens (total of 148m2) were constructed within the grass verge. (Ref 3)

Presence of formal monitoring system

Yes

Presence of indicators used in reporting

Yes

Presence of monitoring/ evaluation reports

Availability of a web-based monitoring tool

No

 

Disclaimer: The data collection was carried out between June and August 2017, the information presented has not been updated afterwards.