Llandudno Water Hardness & Quality Report (2026)

Dŵr Cymru Welsh Water supplies Llandudno, the Victorian seaside resort built on the headland of the Great Orme in Conwy on the north Wales coast, from the Conwy Valley reservoir system in the Snowdonian mountains, treated at Dolgarrog Water Treatment Works on the Conwy River before distribution along the north Wales coast. At 136.5 mg/L (9.6°Clark), Llandudno's water is slightly hard, somewhat more mineralised than the core Snowdonia catchment baseline — reflecting the modest influence of the Great Orme's massive Carboniferous Limestone headland on the supply chemistry as water is distributed across the limestone peninsula.

Llandudno is one of the most geologically distinctive towns in Wales, built on and around the Great Orme — a prominent promontory of Lower Carboniferous Limestone (Dinantian) rising 207 metres above the Irish Sea. While the supply originates from soft Conwy Valley reservoir water draining Snowdonian volcanic and metamorphic rock, the distribution of water through the limestone terrain of the Great Orme peninsula contributes modest calcium bicarbonate to the supply, raising hardness somewhat above the Conwy Valley source baseline. The TDS of 324.6 mg/L reflects this slight calcium elevation above the core upland Welsh reservoir character.

At 136.5 mg/L, Llandudno's water is manageable for domestic use. Descaling the kettle every six to eight weeks is typically adequate. The combi-boiler benefits from a standard scale inhibitor as a precaution. Washing-up liquid lathers well at normal quantities. Taps and shower heads develop only light limescale deposits over several weeks; a monthly wipe with white vinegar keeps fixtures clean. The slightly elevated hardness is a characteristic feature of this North Wales limestone peninsula, distinguishing Llandudno from the softer water of the inland Conwy Valley and Snowdonia communities.