Yr ardal a ddioddefodd waethaf oedd yr A545 rhwng Porthaethwy a Biwmares, lle cafwyd tirlithriad ar ôl i lif y dŵr olchi’r arglawdd sy’n cynnal y briffordd wrth ymyl y Fenai i ffwrdd. Achosodd y dŵr ddifrod pellach i ganllaw pont ym Mrynsiencyn ac i waliau cynnal ar yr A5025.
The worst effected area was the A545 between Menai and Beaumaris which suffered a landslip when the deluge of water caused the bank retaining the highway along the Menai Straits to be washed away. The volume of water resulted in further damage to bridge parapet in Brynsiencyn and retaining walls along the A5025.