ABSTRACT
Dams must be designed to cope with floodwater-by discharging usually over a spillway, or occasionally by opening gates.
Guidelines for the quantity of floodwater for which the design of the dam must provide are contained in a Floods and Reservoir Safety booklet,2 published in 1978 and obtainable from the Institution of Civil Engineers. Although its recommendations are not mandatory, the inspecting engineer would generally expect its requirements to be met. The guide requires that the dam be categorised as follows:
(a) by location, that is, in terms of the risk to life and property downstream; (b) by type, that is, in terms of its ability to withstand overtopping.
