[1][2] Thornton Steward Water Treatment Works (WTW) opened in 1977, and was refurbished in the 1990s.

It was upgraded in 2003,[1] and its mains connections improved in 2007, allowing Yorkshire Water to close older works in Langthwaite and at Cod Beck Reservoir above Osmotherley.

[2] The majority of the water from Thornton Steward is piped to a pumping station north of Ainderby Steeple and from there to Bullamore Reservoir (a system of four covered concrete cisterns on the hillside east of Northallerton).

[5] The reservoir is fed from water pumped from the River Ure, which is extracted at Kilgram Bridge 1 mile (2 km) to the south.

[3] The reservoir is host to the Thornton Steward Sailing Club[7] and is used for fly fishing.