5. c. 44) was an act of Parliament passed by the United Kingdom Government which provided a new set of administrative structures to ensure that drainage of low-lying land could be managed effectively.

The Act sought to set up catchment boards with overall responsibility for each of the main rivers of England and Wales, and to alter the basis on which drainage rates could be collected, removing the 400-year-old precept that only those who directly benefitted from drainage works could be expected to pay for them.

Existing drainage boards and those who lived and worked in the areas they covered made complaints to the Ministry of Agriculture and Fisheries during the 1920s, and the government decided that a thorough review of the situation should be carried out.

[2] The report described the existing laws as "vague and ill-defined, full of anomalies, obscure, lacking in uniformity, and even chaotic."

[3] At the time there were 361 drainage authorities covering England and Wales, and the proposed solution of having catchment boards responsible for each main river, with powers over the individual drainage boards, was essentially the same as had been proposed in 1877 by a select committee of the House of Lords.

[10] Internal drainage boards raised their funding by a levy on the landowners and occupiers of those who lived within their district.

[12] The Royal Commission had identified one hundred catchment areas, based on the main rivers of England and Wales.

A catchment board was set up for all but one of these areas by November 1931, with responsibility for the drainage of 67 per cent of England and Wales.

Rivers in the catchment were the Thaw and Kenson, the Ogmore and Ewenny, the Cadoxton (with Sully), the Avon and the Neath.