Abstract
The Water Act of 1945 can be considered to mark the beginning of modern quantitative hydrogeology in the UK. It introduced a period of some 20 years during which the assessment of resources was the dominant issue as groundwater was developed to meet the increasing post-war demands. The significant effect that groundwater abstraction had on river flows was one of the reasons for the Water Resources Act of 1963. This legislation made regional groundwater management, with the river basin as the basic unit, a practical objective. From 1974, the degradation of groundwater quality and the risk of pollution increasingly became the main issue. Groundwater resources of England and Wales provide 350f public water supplies. About 300f the infiltration to the main aquifers of the Mesozoic and Cenozoic is abstracted. The use of groundwater has increased by 80ince 1948 when data first became available. Groundwater is now seen as a regional resource developed within the sophisticated water resource systems that are necessary for effective river basin management. Development must consider all demands on an aquifer including not only water supply but environmental aspects such as maintaining river flows and wetland environments.