A wnaiff y Gweinidog Cabinet gadarnhau faint o ollyngiadau carthion i afonydd Cymru a gofnodwyd yn ystod blwyddyn ariannol 2025-26?
Information on sewage discharges into Welsh rivers is collected and published by Natural Resources Wales (NRW), in its role as environmental regulator, and by water companies as part of their monitoring and reporting requirements. The relevant sources are set out below:
NRW Storm overflow spill data annual reports
Dŵr Cymru Welsh Water storm overflow data
Hafren Dyfrdwy storm overflow data
Data for the 2025–26 reporting period is not yet available, as Natural Resources Wales publishes this information annually following the receipt and assessment of water company returns. The next update is expected later in 2026.
The Welsh Government will work closely with NRW, Ofwat and the water companies to strengthen monitoring, transparency and accountability, and to drive improvements in water quality across Wales.
(Saesneg yn unig)