River Tyburn

It ran from South Hampstead, through Marylebone, Mayfair, St James's parish/district and Green Park to meet the tidal Thames at four sites, grouped into pairs.

[6] As the map shows, these again split in two, one in the then lower, thus typically Spring tide immersed bank, where Whitehall sits, the other close to Vincent Square, Pimlico, Westminster.

The river's current path is fully enclosed by concrete, bricks, parks and roads, flowing through underground conduits for its entire length, including one beneath Buckingham Palace.

[7] Most of its catchment drains into soakaways in gravel soil, in turn into the chalk water table beneath or into the two-type and hybrid type of drainage set out in Victorian London.

A third distributary is untraced in the building lines and street layout to Thorney Street close to Lambeth Bridge,[6] whilst a fourth distributary forms the natural collect for a 3-metre (9.8 ft) sewer pipe, King's Scholar's Pond Sewer, to the Victoria Embankment interceptor, saving it from discharging west of Vauxhall Bridge.

At Baker Street station, the railway passed beneath the Kings Scholars Pond Sewer, which was supported by a bridge structure attached to the side walls of the tunnel.

[12] The solution adopted was to construct a Vierendeel truss within the existing sewer, fitted with a glass fibre reinforced plastic (GFRP) liner.

The scheme was managed by a joint venture comprising Skanska, MWH Treatment, and Balfour Beatty (SMB JV), with Stantec UK Ltd as a designer and McAllister Group carrying out the on-site work.