South West Water assesses desalination sites in Cornwall to combat drought effects

South West Water is assessing potential desalination sites in Cornwall as the county’s water resources continue to be under “immense and increasing pressure” due to the effects of drought.

David Harris, South West Water's Drought and Resilience Director, said: "Our current system relies heavily on rainfall and climate change has shown us that we need to be developing climate-independent sources of water in Cornwall.

“With 860 miles of coastline, desalination is a logical option to explore and forms part of an additional £45 million investment we are making this year in new water resource schemes.”

Cornwall’s wider supply network

South West Water says the potential sites will be used alongside its wider supply network as and when required to support other sources. 

In an interview with the BBC, Harris said the two plants planned for Cornwall's south coast would provide around 60,000 m3/day. Cornwall currently uses about 170,000 m3/day, meaning more than a third of its water could come from desalination if the plans go ahead.

South West Water is also considering bringing new water sources online, including Hawks Tor, a redundant china clay pit purchased in 2022, which has been converted into a new reservoir. It is the first reservoir brought online by any water company in the country during the ongoing drought, to provide greater longer-term resilience.

The water company has formally applied for a drought permit for Hawks Tor which will allow it to immediately increase water supply to the public and refill Colliford Reservoir, on Bodmin Moor in Cornwall, through the abstraction of up to 8,000 m3/day. The permit will also reduce the risk of further restrictions being required during Summer 2023.

South West Water’s water resources plan 

A public consultation on proposed plans to evolve water resources in the South West was launched by the water company in February 2023. 

Its Draft Water Resources Management Plan sets out its long-term plans to maintain and secure its sustainable water supplies to customers in the future, whilst protecting and enhancing the environment. The consultation will close on 9 May 2023.

Included in the plan, which covers the next 25 years, are proposals to increase the recycling of water, nurture rivers and reservoirs, protect the wildlife that depends on water habitats, and ensure a diversified mix of water resources.

There are also plans to protect household and business customers from the impacts of climate change and increasing hot and dry summers, while ensuring a resilient infrastructure that can support tourism and the long-term economic health of the region.

Harris added: “2022 was an extraordinary and extreme year which provided a challenging combination of dry weather and low river flows, as our region experienced one of the hottest and driest periods in over 130 years.

“Our Draft Water Resources Management Plan 2025 - 2050 shows how we intend to manage water resources, including understanding how customer demand for water and supplies of water will change over time.

“We are determined to make the South West resilient to the increased risks of drought, to support sustainable economic and tourism growth, and to protect our environment, while reducing our carbon footprint.”

Earlier this year, Water Resources South East (WRSE) set a draft regional plan to secure water supplies by focusing on cutting water leakage and desalination.