A £1 million project to help safeguard one of Dorset’s most iconic landmarks has been completed this spring.
The 12-week scheme, which will prevent diluted untreated wastewater from reaching the eastern end of Chesil Beach on the Isle of Portland, was wrapped up on schedule by Wessex Water, working with its sister engineering and construction firm YTL Construction.
Teams intercepted and abandoned an overflow pipe on Chesil Cove, while simultaneously adding more capacity to the existing sewer system to enable flows that carry a mix of rain and foul water to be redirected to a large diameter sewer within nearby streets.
As with most storm overflows, the outfall – sited within a section of the sea defence wall – was designed to operate automatically to protect homes from flooding when the sewerage network became overwhelmed during heavy or incessant rainfall.
Instead, an expanded local sewer network will now ensure the water is safely piped onwards to a nearby water recycling centre for proper safe treatment and return to the environment.
Project manager Bruce McAuslane said: “Wessex Water is investing heavily – more than £3 million a month – throughout the region to tackle storm overflows and progressively reduce and eliminate the discharge of untreated sewage.
“As overflows have always been a part of the network in this country, to eliminate them all immediately would bring huge disruption to communities as well as a significantly driving up water bills and forcing us to dig up huge numbers of roads at once, costing hundreds of millions of pounds.
“However, our planning and modelling at Chesil Cove meant that this was one of those occasions where we could prevent the use of one such outfall and add significant new capacity to the sewer network to handle local flows, without prolonging disruption for nearby customers.’’
He added: “Two teams worked concurrently in Chiswell and on Brandy Row in the Fortuneswell area of the Isle to complete the project, with over-pumping helping to maintain local sewer services during the construction.
“The scheme planning meant we were able to avoid the use of temporary traffic lights that could have caused significant tailbacks up High Street, or any impact on the South West Coast Path, that runs along the Jurassic Coast.
“We’d like to thank the local community for working with us and remaining patient and understanding while the project was carried out.’’
The work continues Wessex Water’s investment in reducing the impact of diluted untreated wastewater on the south coast.
More than £500,000 was invested to protect the coastline around historic Portland Bill Lighthouse from untreated wastewater last year, with a separate pipe installed to remove surface water from a potential 8,000m2 area from the combined sewer system and new storage space constructed.
Further along the coast to the west, an £800,000 investment saw a new pipeline built to pump wastewater away from the villages of West Bexington and Swyre, helping to protect the beach on the UNESCO World Heritage Site coastline, as well as sewer renovation and surface water separation.
Wessex Water’s work to progressively and substantially reduce the discharge of untreated wastewater is continuing over the coming years too, with plans for 2025-30 outlining a £580 million investment – more than double the 2020-25 figure – to reduce the operation of storm overflows, introducing more nature-based solutions and promoting better rainwater management.
The company has asked the Competition and Markets Authority (CMA) to review how much it can invest in vital water and sewerage improvements over the next five years.
This comes after the industry regulator Ofwat’s final determination on Wessex Water’s five-year business plan allowed for £4.2 billion of total expenditure – 17% short of what the company’s own calculations have shown are required to meet its obligations and customers’ expectations, and support growth in the region.
