Thames Water's business customers used 429.12 Ml/d in dry year conditions in 2025-26, 6.52 Ml/d more than its 2024 water resources plan forecast. In London, business demand ran 13 Ml/d above forecast. Government goals require non-household use to fall 9% by 2037-38 and 15% by 2050.
A smaller share, a bigger target
Businesses account for around 15% of the demand for water in Thames Water's area, yet the plan expects non-household water efficiency alone to save 28.40 Ml/d in 2025–2030. On the regulatory measure, a three-year average, business demand was 8.7% below its 2019/20 level in 2025-26.
Meters and letters
More than 90,000 of Thames Water's roughly 170,000 metered business customers now have a smart meter, and the company is fitting around 2,000 a month, with about 27,500 targeted in 2026. In August 2026 it sent more than 2,100 letters about continuous flow, water running around the clock that can signal a leak. The share of smart-metered businesses showing continuous flow fell from 34% to 28%.
Three new initiatives are expected to save around 16 million liters a day: continuous-flow work with water retailers (14.5 million), a Smart Water Saver scheme giving bill credits for cuts of at least 10% (1.1 million) and temporary turn-offs at vacant premises (0.5 million).
The growth problem
The company's 2025-26 plan review says data center demand "will have been accelerated" by the government's growth agenda, that a focus on growth "can conflict" with demand reduction targets, and that engagement through retailers was delayed in 2025-26. Water efficiency work with businesses still saved more than 21 Ml/d in the year, above forecast.
The report sets out how household metering, visits, tariffs and drought restrictions performed, and which government measures the plan's 2050 demand path depends on. The full report, Urban Water Security and Demand Management: Thames Water, is available for USD 499 at https://ourfuturewaterintelligence.com/reports/urban-water-security-and-demand-management-thames-water. For a free overview, read the Thames Water Utility Snapshot at https://ourfuturewaterintelligence.com/utilities/thames-water.