Sussex could see a crisis in water supplies without action to maintain water resources, Southern Water has said.

Unveiling its water management plan, the company warned that its customers could see a shortfall in supply of 300 million litres per day by 2040, increasing to 500 million litres by 2075, due to population growth and climate change.

The firm plans to drive down demand and increase supply, with proposals to reduce leakage by at least 50 per cent by 2050 by “embracing new technology and replacing old water mains”, investing in two new reservoirs, and helping customers reduce average daily use to 100 litres a day.

Nick Price, Southern Water’s water strategy manager, said: “Water scarcity and shortfalls driven by climate change, population growth and increasing demand from industry are challenges we are ready for. This plan sets out the decisions we need to take to make sure there’s enough water for everyone in our region, now and in the future, and to protect and enhance our shared environment.

“We want to embrace new technology, taking actions to both reduce demand and increase supply. This approach will make our services more resilient, meaning the drought restrictions we saw over the summer will become less likely, while we also protect and improve the environment we rely on.”

The publication of Southern Water’s plan comes as Water Resources South East published its own draft regional plan, which forecast that with no action the region could face nearly a billion litres a day in water supply shortfall by 2035, rising to 2.7 billion litres a day by 2075.

Southern Water’s water resources management plan is open for consultation, with people able to make comments until February 20.

The full plan can be found on Southern Water’s website at southernwater.co.uk/our-story/water-resources-management-plan.