Carluke Water Hardness & Quality Report (2026)

Scottish Water supplies Carluke, a market town in the Clyde Valley in South Lanarkshire — set on the plateau above the famous Clyde Valley orchards and adjacent to Lanark — from Daer Reservoir impounded in the Lowther Hills of the Southern Uplands, treated at Daer Water Treatment Works on the upper Clyde catchment. At 66 mg/L (4.6°Clark), Carluke's water is soft, consistent with the upland Southern Uplands acid rock catchment supply that characterises the Scottish Water Lanarkshire and upper Clyde Valley distribution zones.

Daer Reservoir is impounded on the Water of Daer — a headwater tributary of the upper River Clyde — in the Lowther Hills, draining Ordovician and Silurian greywacke and shale uplands of the Southern Uplands fold belt. These ancient sedimentary and low-grade metamorphic rocks are relatively impermeable and calcium-poor, producing soft upland catchment water with limited mineral loading. The resulting 66 mg/L with TDS 142.9 mg/L at Carluke is characteristic of the soft upland Southern Uplands reservoir supply blended with a modest glacial till-derived mineral increment in the valley distribution network.

At 66 mg/L, Carluke's soft water is comfortable for domestic use with minimal limescale demands. Descaling the kettle every two to three months is typically adequate. The combi-boiler benefits from a standard scale inhibitor as a sensible precaution. Washing-up liquid lathers easily with modest product quantities. Taps and shower heads remain largely scale-free with only occasional maintenance. In older properties with lead or copper pipework, residents should briefly run the cold tap before drinking, as soft water can be mildly corrosive to metal plumbing — standard Scottish Water precautionary guidance throughout the soft upland Lanarkshire supply zone.