Consett Water Hardness & Quality Report (2026)

Consett, the former steelworks town in west County Durham perched on the ridge above the Derwent valley, is supplied by Northumbrian Water from its own doorstep source: Derwent Reservoir, impounded on the River Derwent just a few miles south-west of the town above Edmundbyers. The Derwent headwaters drain the North Pennine moors of Northumberland and west County Durham — bleak upland terrain underlain by Carboniferous Millstone Grit, Carboniferous shale and Coal Measures — hard silicic rocks that contribute minimal dissolved calcium to rainfall runoff. Water is treated at Mosswood Water Treatment Works near Consett and distributed to Consett, Lanchester, Annfield Plain and the west Durham network. The low TDS of 209.8 mg/L confirms a predominantly moorland surface-water supply with very limited mineral content.

The Derwent catchment above Consett sits squarely within the North Pennine Orefield fringe, but the reservoir intake area drains predominantly over Carboniferous Namurian shale, Millstone Grit and Lower Coal Measures — calcium-poor, silica-rich formations that produce inherently soft surface runoff. The reservoir's depth and cold upland temperature further limit calcium dissolution. At only 89 mg/L Consett has genuinely soft water — considerably softer than Stanley (175 mg/L) just 8 miles to the east, where Northumbrian Water's distribution network picks up greater Magnesian Limestone groundwater input from the eastern supply zone.

At 89 mg/L Consett's water is soft and limescale is rarely a significant problem. Kettles accumulate only a light film of scale over two to three months of use and need descaling just three to four times a year — white vinegar left overnight is more than adequate. Shower screens remain relatively clean and taps show little mineral spotting. Washing-up liquid lathers freely. Combi-boilers and washing machines face very low scaling risk. Consett's once-mighty steelworks depended on vast quantities of process water from the Derwent catchment; today that same catchment delivers one of County Durham's softest household water supplies.