A London Borough asked WSP to design a SuDS for a 7,000m2 catchment in one of its low-emission neighbourhood. The challenge was to design a resilient solution that would reduce the risk of future flood events, enhance the safety and aesthetic appeal of the streets and positively contribute to biodiversity, air quality and public health.

Solution

WSP’s design concept aimed to work with nature to create a lasting solution that could be retrofitted with minimal disruption into the busy public highways. We designed nine bioretention areas (rain gardens) with a combined surface area of 129m2.

Results

• Impact was monitored closely and no floods were reported during storm events.

• Planting and silt traps are also serving to improve the quality of the water entering the sewer

• Pedestrian safety has been enhanced because the gardens act as a buffer between pavements and highways

A local authority in the South-East appointed WSP on this scheme to prevent reduce heat stress along several residential streets in a seaside town. The brief was to initially limited to adding key green infrastructure to the urban landscape. However, forward thinking by the Client took this opportunity to also improve the existing surface water drainage in an area known to contribute to localised surface water flooding.

Solution

WSP designed this sustainable drainage scheme (SuDS) using a natural approach to water management within the urban environment, combining green spaces and sustainable water management. Using a combination of NbS, technology and engineering, the scheme:

Results

• Reduced flood risk to 30 properties within the Key Flood Risk Area

• Generated a total £2.5m payback in flood protection over the total design life of 50 years

• Introduced 11 new sustainable tree pits and a total of 32 trees

• Reduced carbon footprint with the installation of recycled-plastic modular structures for water attenuation

Liverpool City Council was awarded €3.4m over a 6-year period for a pioneering research and innovation-led project to demonstrate the impact of investment into retrofitting nature-based solutions within an urban environment. Urban Green-Up is an EU-funded initiative which set the challenge to develop, apply and validate a methodology for re-naturing urban spaces to mitigate the effects of climate change, improve air quality and water management, and increase sustainability.

Solution

WSP have been involved in the feasibility, design, and installation, identifying and developing a range of nature-based solutions to link strategic sites and increase biodiversity along corridors within the city. Interventions include green walls, floating ecosystems, sustainable drainage, tree planting and pollinator verges. A key aspect of the project was to monitor the multiple benefits of each intervention and the data analysation has shown significant environmental, economic and social impacts.

Results

• Improved air and water quality

• Reduced carbon emissions

• Enhanced biodiversity

• Improved mental/physical wellbeing

• Improved accessibility for green corridor routes

• Reduced surface water flood risk

• Lower air temperatures and thermoregulation

United Utilities (UU) built a new pipeline to provide West Cumbria with a more resilient supply of water from Thirlmere Reservoir, switching to the new system in July 2022. Once all customers have been transferred UU will stop taking water from several local water sources, including Crummock Water, Chapelhouse Reservoir and Overwater. Consultation is currently under way on returning these water bodies to their natural state.

Solution:

WSP is a working with UU, the Environment Agency and Natural England on this project which plans to remove redundant infrastructure to re-naturalise Park Beck. This will return the lake and its surrounding rivers and streams to their historic natural levels, which aims to deliver significant environmental benefits.

Benefits:

• WSP investigations, surveys and assessments will help deliver the schemes’ environmental benefits

• Includes restoration of natural flows along becks and rivers in the surrounding catchment areas.

• Other environmental benefits, including restoration of natural salmon habitats.