WRSE sets out plans for three new reservoirs in south east

The five regional water resource management groups have this week published their proposed strategies for long term resilience in the face of climate change and population growth. Utility Week explores Water Resources South East's draft and speaks to the chair and managing director behind the strategy.

Water Resources South East (WRSE) has proposed adding three new reservoirs, a desalination plant and five water recycling schemes in the south east of England by 2040.

The measures are all part of phase one of its three-phase strategy to ensure adequate water supplies in the region over the next 75 years. The six member water companies of WRSE are Portsmouth, Affinity, SES, South East, Southern and Thames.

Phase one addresses a single scenario which forecasts that, without action, an extra one billion litres of water per day will be needed in the region between 2025 and 2040 due population growth and the effects of climate change. To reflect the increased uncertainty beyond then, phase two, covering the period 2040 to 2060, branches into three scenarios reflecting differing levels of population growth and success in the prior phase. Each of these scenarios has a corresponding strategy featuring varying combinations of transfers, desalination, water recycling and demand management. The preferred path at phase two will be dependent on the outcome of phase one. They similarly branch into nine total scenarios for phase three covering the period 2060 to 2100.

WRSE said demand management from water efficiency, leakage reduction and drought management measures such as hosepipe bans could meet, offset or eliminate 54% of the forecast one billion litres of additional daily demand by 2040, whilst three new reservoirs could meet another 21%.

Drought orders and permits, which will remain in place to 2040, could cover a further 9%, as could water recycling, and 5% could be met through increased capacity at treatment works or expansions to the distribution network.

The cost of these measures would be £8 billion, with £5.1 billion being spent on water efficiency and leakage.

WRSE said in the most extreme scenario for phase two, daily water demand would increase by 2.6 billion litres between 2025 and 2060 based on forecast population growth of 5.3 million over the period. It said the region would be more reliant on water recycling and transfers from other parts of the country in this scenario, with another ten water recycling schemes, six more desalination plants and five further reservoirs providing 1.6 billion litres of additional water per day to help meet the increase in demand.

The EA published its first National Framework for Water Resources in 2020 to bring together water companies and large users to work across regional boundaries to develop plans for each region’s water needs. Plans from the five regional groups are intended to fit together as a national solution.

Given the greater uncertainty beyond 2040, WRSE chair Chris Murray, said: “We need to get on with some ‘no regrets’ investment quickly and then make sure we have flexibility to adapt as things emerge.”

With such a high reliance on demand reduction in the plan, Murray said input from outside the sector is needed around education and behaviour change: “We need to get the message across that there is a major problem here and how people can be part of the solution. As a country we have woken up the challenge of climate change but not yet on the water front. Who will be our Greta Thunberg for water?”

The first phase focuses heavily on demand management, which the group anticipates will be advanced by innovation and new technologies during that time, particularly for leakage. Managing director Trevor Bishop added that the scale of demand reduction is profound compared to what has been done previously and would require mass smart metering as well as behaviour change. He said government intervention through policy that supports demand reduction could save £3 billion compared to no support.

The first phase also includes one desalination plant, potentially at Shoreham in Sussex, with further schemes possibly needed in Kent and Sussex in the subsequent phase. As part of the Regulator’s Alliance to Progress Infrastructure Development (RAPID), Southern Water had proposed a desalination plant in Hampshire but found it unsuitable.

The plan will be updated every five years and actions monitored to stay on track with delivery. WRSE, which formed two years ago, assessed more than 2,400 scenarios and schemes to identify the most suitable options for the regional plan.

A consultation on the draft proposals will run until 14 March.