Investment of £15.6bn needed to secure water supplies in South East

Water Resources South East (WRSE) has identified the need for £15.6 billion of investment over the next 50 years as part of its draft regional plan for securing water supplies in the South East of England.

The alliance of water companies said the investment is necessary to cut leakage, lower usage, develop new water sources and transfer supplies from other parts of the country as they seek avoid potential daily shortfalls in the “water-scarce” region of 0.8 billion litres by 2035 and 2.7 billion litres by 2075.

The latter equates to 40% of the total volume of water currently supplied by the six companies that make up the alliance – Affinity, Portsmouth, SES, Southern, Southern, South East and Thames.

The draft regional plan, covering the period 2025 to 2075, is an update to the emerging plan published by WRSE in January.

There are multiple versions of the plans, which vary according to the goal they seek to achieve and in turn branch into nine potential pathways based on population growth and the extent of climate change.

The £15.6 billion of investment identified by WRSE would be needed in the “best value” plan on the pathway in which there is medium population growth and high levels of climate change.

In this scenario, the region would need additional water supplies of 2,670 megalitres per day (Ml/d) by 2075: 1,360Ml/d to allow more water to be left in rivers, streams and underground sources; 240Ml/d to address the impacts of climate change; 605Ml/d to supply the increased population; and 465Ml/d to make water supplies resilient to drought.

The avoid this potential shortfall, leakage would need to be cut in half and per capita consumption would need to be reduced to 40 litres per day on average by 2050.

Between 2025 and 2035, water companies in the region would also need to:

• Complete the construction of one new reservoir in Hampshire and begin building three more in Oxfordshire, Kent and West Sussex
• Build one desalination plan on the Sussex coast
• Develop six water recycling schemes in Kent, Sussex, London, Hampshire and the Isle of Wight
• Use the Grand Union Canal to transfer water from the Midlands
• Develop new transfers to move up to 600Ml/d around the South East and between other regions

Between 2035 and 2075, they would need to:

• Build one new reservoir in East Sussex
• Store extra water underground at three sites
• Build desalination plants at five locations in Kent
• Develop another six water recycling schemes across the region
• Transfer more water from the Midlands and the North West using the River Severn and the River Trent
• Develop new transfers to move up to 1,400Ml/d around the South East and between other regions

Chris Murray, independent chair of WRSE, said: “The drought that developed over the summer affected most of the country and reinforced the need for us to invest in our collective water resources, so we mitigate the climate emergency, provide long-term protection to the environment, and avoid the far-reaching economic and societal consequences that emergency restrictions to water supplies would bring.

“The draft regional plan we have prepared for South East England makes the case for a long-term programme of investment in our water supplies. It includes delivering significant reductions to how much water is used and wasted, new reservoirs so we can capture and store more water, transfers so water can be moved within and between regions, and schemes that will safely recycle water so it can be used again.

“It responds directly to the challenge set by government and regulators to build resilience while improving our water environment and will not only provide enough water for future generations but deliver wider benefits to people and places.”

A consultation on the plan is open to response until 20 February 2023.