Waterbeach

Cambridge, United Kingdom

Year

2019-present

Duration

20 years

Cost

Unknown

Location

United Kingdom

Project achievements

Environment benefitted

Encourages active travel through foot and cycleways

Used engineering skill

Used nature-based solutions to address flood risk

Area improved

Provides 6,500 new homes five new schools

Redeveloping a former barracks and airfield using nature-positive solutions

Waterbeach is a major redevelopment of a former barracks and airfield, located just four miles north of Cambridge, UK.

The scheme will be delivered in stages over the next 20 years and provide:

6,500 new homes
five new schools
extensive on and off-site cycle connections
public transport services
active travel schemes

The Waterbeach site is bordered closely by the River Cam, and it’s vulnerable to flooding.

The team was concerned that the development could make floods worse by building on areas where water would’ve previously drained away (ie. soil).

So they explored nature-based solutions (NBS) as a way to mitigate the development’s impact.

The team employed a variety of NBS, including sustainable urban drainage systems (SuDS).

Did you know …

The development includes over 10km of foot and cycleways to promote active travel.
The project team designed the first primary school that has no vehicle access, encouraging parents and children to use active travel.
The development is supported by a sustainable transport hub, which includes bus stops and cycle hire for new residents.

Responding to flood risks

Waterbeach’s location is a large contributor to the some of the challenges that the project team has had to overcome.

Free draining soils lead to a variable water table, the boundary between the soil surface and where groundwater fills every gap between sediment and rocks. Water tables can vary due to changes in rainfall.

This, combined with a flat geography and a history of localised flooding, means it’s a potential flood zone.

Responding to this was an essential part of the infrastructure planning.

Detailed topographical surveys and groundwater monitoring were conducted through a number of seasons.

These investigations led the team to explore nature-based solutions as a way of mitigating the impacts.

How is Waterbeach using nature-based solutions?

Some of the NBS used were controlled discharges into ditches, with excess stored onsite in clay-lined SuDS.

These SuDS features have, in turn, provided new habitats for other species, boosting biodiversity, and made the area nicer overall for end-users.

The team also raised the earthworks by as much as two metres in some locations in order to address the flat landscape.

Nature-based solutions also reduce the need for pumping water onsite and will have a longer design life with less ongoing maintenance.

Addressing possible land contamination

Another challenge of developing a former military site is having to address the possibility of contamination.

The main contaminants were likely fuel spills, but there was also a risk of unexploded ordnances (explosives that didn’t detonate when they were deployed) and asbestos.

More recent investigations have also found evidence of forever chemicals from firefighting foams.

Through a series of surveys, the team established the areas most likely to require remediation (or treatment).

They worked closely with the Environment Agency and relevant stakeholders to deliver a remediation strategy which ultimately reduced any waste going to landfill.