The CEO of Southern Water has made the case for why water bills are going up as customers are set to see an increase of almost 50 per cent.

Southampton residents questioned price rises as it was revealed in January that the average yearly bill will reach £703  - a 47 per cent increase.

It comes as the firm has appealed against a decision by Ofwat and hopes to increase bills further.

Lawrence Gosden, CEO, has said that increased bills will help the utility firm prepare for climate change and build for the future.

The utility firm’s owner has pumped in cash injections.

"What shareholders are paying for is effectively getting the company's operating performance back on track," he said.

"That's replacing existing equipment with rebuilding pumping stations. All of those kinds of things.

"But to change the company, to rebuild all of those plans and to prepare them to be able to deal with climate change and drought in the future, and redesign the sewer system, that’s different.

"That’s new work. That shouldn’t have happened in the past, that’s what now needs to happen. That work will be paid for through customer bills."

READ MORE: Council takes part in major water recycling project consultation

Mr Gosden acknowledged that there is still "a lot of work" to do to get Southern Water "back on track", but he confirmed that these repairs will be paid for by shareholders.

"So customers are not paying for that, but what we also have to have to do is we've also got to prepare the company to defeat climate change," he said.

Southern Water is also expanding the range of support available to customers most affected by rising bills, include increasing their Hardship Fund to £1.25m.

READ MORE: Council takes part in major water recycling project consultation

Southern Water is looking to rebuild 40 per cent of Hampshire's water supply, which Mr Gosden called a "really big and unfortunately expensive job."

The CEO also said that focus is being paid to meet demand to stop storm overflows, where the sewage system pumps water into rivers as a pressure relief.

A mock-up of Havant Thicket Reservoir which is set to open in 2029.A mock-up of Havant Thicket Reservoir which is set to open in 2029. "It’s just how sewer systems work around the world, and in the UK, we want to change that," he said.

To make those changes, entire systems would need to be re-plumed and re-designed. 

Southern Water is also working with Portsmouth Water on Havant Thicket Reservoir, a water recycling scheme that will alleviate pressure on using natural water sources from the Itchen and Test.

"They're the two big chunky investments that mean we need customer support in bills to pay for," Mr Gosden said.

Customers are being supported with social tariffs for those in most need with around 155,000 homes expected to be on this list by 2030. 

Around £1.25m will be put aside for a hardship fund for customers who need this, an increase in the current fund.