ONE OF THE MOST significant risks to a dam is the inability to pass flood flows. Where there is a fixed level spillway, security is reliant upon the flood-flow being less than the spillway design capacity. Many dams, however, cannot incorporate a fixed spillway of sufficient dimensions and therefore employ spillway gates to provide the additional capacity. Safety is then dependent on the reliability of the gates and associated machinery. There are many well documented serious incidents, however there are many more near-misses, leaving an uncomfortable feeling that the full nature of the risks associated with dams and reservoirs are not properly quantified and/or understood. Several recorded incidents where the inadvertent opening of spillway gates has led to fatalities, generally the drowning of members of the public downstream, highlights the need to recognise that the subject of safety in relation to protection gates requires careful, documented, thought.
展开▼
