The £44.7 million enforcement package is greater than the penalty Ofwat would otherwise have imposed on the company, which would have been be £40 million, or 7.5% of Dŵr Cymru Welsh Water’s annual turnover). This ensures the money is spent directly on environmental improvements rather than returned to HM Treasury.

The package will reduce spills at specific overflows and improve river water quality in extremely sensitive catchments with the money being funded by the company, rather than added to customer bills. Dŵr Cymru Welsh Water is also required to rectify all identified breaches and ensure its future compliance.

Ofwat previously announced on 12 March that the company had failed to operate, maintain and upgrade its wastewater treatment works and networks adequately to ensure that they could cope with the flows of sewage and wastewater. A consultation period followed where customers and stakeholders provided feedback on the provisional decision.

Having assessed all the responses received, Ofwat has formally accepted the enforcement package which includes redress to customers and the environment including:

This closes the seventh case in Ofwat's sector-wide wastewater investigation and takes the total of resulting enforcement packages and fines across the sector to more than £300 million.

Lynn Parker, Senior Director for Enforcement at Ofwat, said:

“Our investigation found serious and unacceptable breaches in how Dŵr Cymru Welsh Water has operated its wastewater assets which has resulted in excessive spills to the environment.

“With this investigation now concluded, we expect the company to focus on putting things right so that customers can regain trust in their water company. We are playing our part in holding companies to account with this announcement marking the seventh case we have now closed in our sector-wide investigation, taking the total of resulting enforcement packages and fines to more than £300m.”

The company will be required to deliver the redress measures included in its enforcement package during 2025-30. This is investment over and above existing plans the company committed to as part of the 2024 Price Review. These costs will be absorbed by the company and not funded through higher customer bills.

Delivery of the package will be monitored by Ofwat, and the undertakings are legally enforceable.

The regulator said that in agreeing the enforcement package, it means that the money will remain in the water sector and be spent on making improvements for the benefit of Dŵr Cymru Welsh Water’s customers and the local environment.