A large dam is classified as one with a minimum height of more than 15 metres from its deepest foundation to the crest.
A dam between 10 and 15 metres in height from its deepest foundation is also included in the classification of a large dam provided it complies with one of the following conditions
a) length of crest of the dam is not less than 500 metres or
b) capacity of the reservoir formed by the dam is not less than one million cubic metres or
c) the maximum flood discharge dealt with by the dam is not less than 2000 cubic metres per second ord) the dam has specially difficult foundation problems, ore) the dam is of unusual design.