The second half of the 20th century saw over 60 large concrete dams built i
n Britain for a wide variety of water supply and hydroelectric reservoirs.
However, with increasing social and environmental concerns about such proje
cts, the Maentwrog gravity dam built 10 years ago could be the UK's last. T
he late Geoffrey Binnie described the development of concrete and masonry d
ams in the UK up to 1942, from Vyrnwy to Haweswater. This paper aims to com
plete that history. It describes the development of concrete dams, from sim
ple mass-concrete gravity structures to prestressed and double-curvature ar
ch designs, and the effect of improving technologies. It also looks at how
the expertise of UK dam designers has been exported worldwide and concludes
with a brief review of the World Commission on Dams report.