The average Dŵr Cymru Welsh Water household customer bill will increase by 4.8% in 2026-27, from £652 to £683.
The price rise will help ensure the company delivers its aim of providing world class water services to the communities it serves.
Following the price rise Welsh Water customers will on average pay less than £2 a day for their water and wastewater services.
This increase is among the lowest for water and sewage companies across Wales and England.
Between 2025-30 more than £4bn will be invested in Welsh Water’s services – double the investment of 2020-25 – and includes £2.5bn on projects to improve the environment.
The investment will fund work to reduce pollution, upgrade and build new vital assets, reduce leakage, and improve water quality.
The company serves 3m people across Wales, Herefordshire and parts of Deeside. Its infrastructure includes more than 36,500km of sewers, 834 wastewater treatment works, more than 27,500km of water mains, 65 water treatment works and 92 reservoirs.
Welsh Water’s most vulnerable customers can benefit from the company’s social tariff schemes that help make bills more affordable.
The company’s not-for-profit model allows any surplus money to be re-invested, providing £14.7m of social tariff provision with the capacity to assist 147,000 customers.
Dŵr Cymru Welsh Water Chief Executive Roch Cheroux said:
“As I start my new role at Welsh Water my focus is firmly on aiming at delivering world class water services for our customers and their communities.
“It’s vitally important that we deliver the service customers want at a price that they can afford.
“We understand that the recent price rises have been substantial at a time of rising costs across the board for our customers.
“Our aim is to deliver value for money, and we will work tirelessly to show our customers the value of all that we do for their communities and the environment.”