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Portsmouth Flood Alleviation Scheme

A collaborative project utilising assets owned by multiple agencies

  • 6

    Cubic Metres per Second of Peak Flow

  • 95%

    Customer Satisfaction

  • 34000

    Tonnes of Reused Waste

  • Portsmouth, United Kingdom

    Portsmouth, United Kingdom

No-dig techniques and innovative use of green spaces provide a sustainable drainage solution for Portsmouth

The city of Portsmouth suffered catastrophic combined sewer flooding in September 2000 from an extreme rainfall event. In 2015, in an effort to prevent a similar event occurring, we completed a major surface water management scheme for our client, Southern Water. The ultimate goal? To disconnect 34 hectares (equivalent to nearly 70 football pitches) of paved area from the combined sewer, diverting six cubic metres per second of peak flow from the combined system—an Olympic swimming pool every seven minutes.

Collaboration was vital in managing the needs of many different stakeholders, including schools, the public, property owners, city councilors, sports clubs, and golf courses. Communication was essential and included giving talks, running competitions in schools, letter drops, local resident evening drop-in events and advertorials in city wide magazines. Overall, we achieved an unheard of 95% customer satisfaction grade in surveys carried out post construction. The commitment of the team to contribute to the sustainability of the project resulted in an unprecedented level of collaboration between the professional bodies.

Now complete, this project was a great success—99.9% of the 34,000 tonnes of waste generate was able to be diverted from landfills for re-use.

At a Glance

  • Southern Water
Engineering Excellence - Special Award for Community Benefit (2015)
Considerate Constructors - National Site Award Winner (2015)
Considerate Constructors - Most Considerate Site Runner Up (2015)
Meet Our Team

Robert McTaggart, Technical Director

Efficiency is the combination of effectiveness and productivity.

Robert McTaggart

Technical Director

We’re better together

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  • Design your career

    Work with passionate people who are experts in their field. Our teams love what they do and are driven by how their work makes an impact on the communities they serve.

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