Stratford Water Hardness & Quality Report (2026)

Stratford, in the London Borough of Newham in east London — world-famous as the site of the 2012 Olympic Park — is supplied by Thames Water from the Lee Valley Reservoir chain and the Lee Valley Chalk Aquifer of Hertfordshire. The Lee Valley reservoirs — Walthamstow, King George, William Girling, and Chingford — impound and store River Lee water carrying dissolved chalk calcium from the Hertfordshire chalk catchments. Thames Water also draws chalk borehole groundwater from the Lee valley chalk and distributes through the east London supply network. Stratford's east London Newham position in the Thames Water supply zone is directly influenced by the chalk of the Hertfordshire Lee valley — one of the most productive chalk aquifer systems in England — producing consistently hard water for the east London Borough.

Stratford's hard water — 205.5 mg/L (14.4°Clark) — reflects the Lee Valley Chalk Aquifer influence on Thames Water's east London supply zone. The Drinking Water Inspectorate (DWI) classifies this supply as hard.

Limescale is a persistent household challenge in Stratford. At 205.5 mg/L, limescale forms in kettles within two to three weeks and monthly descaling is advisable. Combi-boiler heat exchangers accumulate deposits steadily — annual boiler servicing and an in-line scale inhibitor are recommended. Showerheads, taps, and shower screens develop regular deposits. Washing-up liquid lathers poorly. Using Calgon monthly in the washing machine and maintaining a regular descaling routine is important limescale management for Stratford households.