Prof Ian Walker, head of psychology at Swansea University, said people could be “constrained by automatic habits” when it comes to water usage.
He said: “You might think, ‘I should take shorter showers’, but once you get in there, you go into auto-pilot and take the same time regardless.
“One of the best things you could ask people to do is don’t have showers and don’t wash your clothes. But that’s not going to happen either.”
He suggested an easier approach was to lock-in water savings measures, such as getting a low-flow shower.
“You do that once as a deliberate choice, but then you never think about it again.”
Welsh Water said it recognised that household budgets remain under pressure and understand that any increase in bills is difficult for customers.
“The additional income will support our investment of more than £4bn between 2025 and 2030 to maintain and improve essential services, including work to reduce pollution, improve water quality, reduce leakage and upgrade vital infrastructure,” a spokesperson said.
“The revenue we receive from customer bills is our sole source of funding for maintaining services and upgrading our infrastructure.
“Without profit-driven pressures, any financial surpluses are reinvested for the benefit of our customers, to improve services, support vulnerable households and address environmental challenges.
“We urge any customer who is worried about paying their bill to contact us. Our social tariffs and wider support schemes can make bills more affordable for eligible households.”
