The length of the top or crest of a dam, including the length of the spillway, powerhouse, navigation lock, fish pass, etc., where these structures form part of the length of a dam. If detached from a dam, these structures would not be included in the crest length.
CREST LENGTH
Meaning of CREST LENGTH in English
Environmental engineering English vocabulary. Английский словарь экологического инжиниринга. 2012