Queen Mary Reservoir

Construction of the Littleton Reservoir was authorised under the provisions of the Metropolitan Water Board (Various Powers) Act 1921 (11 & 12 Geo. 5, c.cxv). It was designed by the Board’s Chief Engineer Henry Stilgoe (1867-1943) and was completed in December 1924. Some sources state that the reservoir was designed by John Watson Gibson for the Metropolitan Water Board. It was formally opened by King George V in June 1925 as the Queen Mary Reservoir, renamed for the Queen Consort, Mary of Teck; a plaque commemorates the event. It was the largest reservoir in the world at that time. In 1943, during World War II, the reservoir was used for testing submersibles. The submersible was nicknamed…

The reservoir embankment has a puddle clay core extending down into the underlying London Clay and gravel/earth shoulders at a slope of 1 in 3. The top of the embankment is 12 m above the surrounding land. The key engineering parameters are: {| class="wikitable" |+Queen Mary Reservoir !Parameter !Value |- |Maximum embankment height |12 m |- |Length of Embankment |6,324 m |- |Total capacity |30.4 million m³ 30,400 megalitres |- |Surface area |2.863 km² |- |Inflow capacity |770 Ml/d |- |Emergency drawdown |0.75 metres within 24hrs |} The reservoir has a 1 km central gravel/earth embankment breakwater running north–south and designed to reduce wave action.