Construction of the Littleton Reservoir was authorised under the provisions of the Metropolitan Water Board (Various Powers) Act 1921 (11 & 12 Geo.

[4] Some sources state that the reservoir was designed by John Watson Gibson for the Metropolitan Water Board.

The key engineering parameters are:[7] The reservoir has a 1 km central gravel/earth embankment breakwater running north–south and designed to reduce wave action.

Sand and gravel were formerly dredged from the reservoir, making the bottom uneven and affecting water circulation.

[4] In 2008 Thames Water digitally modelled the bottom to identify high points where aggregates could be removed.

[4] A jetty and aggregate processing facility was constructed on the west side of the reservoir just north of the intake.

[7] The reservoir and the land to the west are designated Sites of Nature Conservation Importance, covering some 360 ha and noted for their varied bird life.

It owns a subsidiary company Queen Mary Sailsports, bringing all training operations "in house".