Bridget Joyce Square SuDS project
This page provides an overview of the Bridget Joyce Square SuDS project, which helped transform a dangerous and ugly road into a beautiful, safe community space. At the same time, it helps to improve water quality and reduce surface water flood risk.
Where & why was this SuDS project built?
Bridget Joyce Square was created from part of what was Australia Road, in Hammersmith & Fulham’s White City housing estate. There were two main reasons for installing SuDS here:
- the project is located between a school (Randolph Beresford Early Years Centre) and two playgrounds. The road was dangerous for children crossing between the school and playgrounds and made school drop-off and pick-up difficult
- the road was at high risk of surface water flooding, partly because it is in the Counters Creek Sewer catchment
Counters Creek is one of London’s ‘lost’ rivers and is fully incorporated into the sewer network. Its catchment is well known to suffer from sewer flooding after heavy rainfall. because of:
- the loss of open space in the area
- the large number of basements that have been built at the same level as the sewer system.
Because of this, a storm relief tunnel is being built, but this will need to be supported by SuDS across the whole Counters Creek catchment.
The existing section of Australia Road was converted from a road into a pedestrian and cyclist space. There is still access for emergency and maintenance vehicles (Figure 8). This provides a safer link between the school and playgrounds.
Bridget Joyce Square was made using 1,320m2 of permeable block paving. This traps rainfall underground and directs it to a series of bio-retention basins and rain gardens. These basins and rain gardens also take rainwater from the roof of the school via disconnected downpipes. They provide over 55m3 of storage capacity. Fifty trees and 2,500 plants have been put in to soak up rainwater, increase biodiversity and make the area more attractive.
Most new SuDS developments restrict water flowing into the sewage systems to five litres per second (l/s). The reason for this is concerns that slower flows can cause pipe blockages. This project designed the drainage outlets to reduce the risk of blockage even with flows of 1 l/s. Over a single year, the scheme will halve the volume of water entering the sewer.
It's important to note that the road renewal would have happened anyway. Incorporating all the different SuDS measures into the project probably doubled the construction costs. But without the SuDS measures there would not have been as much greenery and the result would probably have been of much lower quality, with none of the added benefits that green SuDS measures provide.
The drainage outlets are easy and safe to access for a single member of council staff to inspect and maintain. The rain gardens and car park surfacing will be maintained by the school. Hammersmith & Fulham Council’s Highways team will maintain all other features, including the basins and chambers.
A range of technologies have now been installed, which transmit data wirelessly on the scheme’s performance. These include a full weather station, flow sensors, a depth gauge and a moisture sensor. There are some interesting initial findings. However, it will take time to gain a full picture.
Key aims of this project were education and community engagement. Early consultation found locals wanted to keep a small wall in front of the school as a focal point for students. This concept was then embedded into the design of the SuDS scheme and enhanced to create a ‘wiggly wall’.
Artistic rain cascades allow the public to see rainwater diverted from the roof into the raingardens. Permanent education boards explain the idea and how the scheme works. Project team members have talked about the scheme in local school assemblies. The students of three local schools also took park in a SuDS-themed art competition for the opening of the space.
The scheme provides a new events space for the local community by the school entrance. This space benefits from improved lighting, CCTV, and electricity and water points for managed use during an event. There is also anecdotal evidence that parents are beginning to use the space to socialise during school drop-off and pick-up.
Since opening in late 2015, the scheme has won several awards, including:
Main challenges and lessons learned
A big effort was made to attract funding from local organisations and companies likely to benefit from the scheme. This included the drainage undertakers, nearby businesses, and sports clubs. However, whilst there was general support, no funding was made available. Instead, all project costs were funded by the borough and its lead local flood authority, the GLA, and TfL.
Commercial confidentiality meant external designers couldn’t see the highways framework contract rates. As a result, the materials proposed were either not within the contract or were not the best value option. This led to extensive re-working of the design. The council is now investigating how to get around this problem, without disclosing sensitive information.
Procurement and planning
Many monitoring companies specialise in just one type of technology. Sourcing all the various sensors needed under one contract was hard. This led to it being installed several months after the scheme opened.
The scheme was large and complex, with many potential pitfalls for construction engineers. To help reduce these, SuDS specialists involved in the scheme’s design gave expert supervision at key points during the construction. There were several pre-construction meetings held to talk about construction phasing and methodology for some of the more complex elements. Involving the contractor earlier in the design process would have reduced the need for redesign.
Browse pictures from the Bridget Joyce Square project
Photos credit: London Borough of Hammersmith & Fulham
Bridget Joyce Square facts and figures