Caiff diogelwch cyforgronfeydd dŵr mawr yng Nghymru a Lloegr ei lywodraethu gan ddarpariaethau yn Neddf Cronfeydd Dŵr 1975 (Deddf 1975) sy’n ceisio lleihau’r risgiau i ddiogelwch y cyhoedd a allai ddeillio o fethiant cronfa ddŵr neu argae. Gallai methiant o’r fath arwain at lifogydd difrifol.
The safety of large raised reservoirs in Wales and England is governed by the provisions in the Reservoirs Act 1975 (1975 Act), which aims to reduce the risks posed to public safety from a reservoir or dam failure which may lead to severe flooding.