The village of Capel Celyn and the Tryweryn valley near Bala were flooded in 1965 in order to supply water for the City of Liverpool. Eight hundred acres of land was flooded and the school, the post office, the chapel and the cemetery lost. This was to create the Llyn Celyn (Celyn lake) reservoir to supply Liverpools residents with water.
The Tryweryn Bill was passed by Parliament on 1 August 1957. it was a private measure, sponsored by Liverpool City Council and passed by Harold Macmillan's Conservative government, with the support of Henry Brooke, the Minister for Welsh Affairs. Compulsory purchase orders were made on land in order for the reservoir to be built. Although opposed by most of the Welsh Members of Parliament, they were powerless to stop the development because the government was determined to push the Bill through Parliament.