Barmouth Viaduct Gardens Flood Alleviation Scheme

Viaduct Gardens Flood Alleviation Scheme, Barmouth, Gwynedd

The area known as Viaduct Gardens in Barmouth has suffered a number of flood events over recent years. The source of flooding is complex and has been a result of the sea over topping the existing sea wall and inundation of the existing surface water network.

Flooding has also occurred during events where tidal waters impede the free flow of the surface water network due to tide locking, and the primary sea wall suffered storm damage in 2020 which caused a partial collapse of the wall.

The works are being managed by the Principal Contractor, Griffiths, working for Cyngor Gwynedd and consists of construction of a new sea wall, a new secondary set back wall, a new surface water and associated pumping station, installation of four new flood gates and associated landscaping works.

The works include the following activities:

• Existing seawall to be rebuilt with precast concrete units, faced with stone masonry cut from stones in the existing seawall.

• New raised section of seawall immediately behind the rebuilt seawall, with stone block masonry finish.

• Existing ‘temporary’ rock armour to be redistributed across the front of the seawall with additional smaller stones incorporated as required.

• New surface water outfall on the beach further out than the existing viaduct.

• Existing outfall and pipe onto beach to be removed

• Single and double leaf flood gates

• Control box for new underground pumping station and new chambers (arrangement to be confirmed)

• New setback wall at the rear of the garden with stone block masonry finish

• New gulleys and chambers to increase highway drainage capacity at low point (arrangement to be confirmed)

• Existing paviors replaced with raised pedestrian crossing (blending)

• Existing stub wall and railings removed

• Paved area incorporated into Viaduct Gardens

• New railings creating new perimeter to viaduct gardens

• New raised section of seawall tapers down from 5.60 in corner to ground under the viaduct

Completion is expected during Spring 2026