: The Ogee shape is optimized to maintain atmospheric pressure at the design head, preventing cavitation. Excel allows you to quickly iterate through different design heads to find the point where discharge efficiency is maximized.
But for the An XLS is faster, more transparent, and less error-prone than black-box software. ogee spillway designxls better
If you’ve ever designed a concrete gravity dam, you know the Ogee spillway is both a thing of beauty and a hydraulic headache. Getting that perfect “S” curve—where the lower nappe of the waterfall just kisses the crest—requires iteration. : The Ogee shape is optimized to maintain
The discharge over an Ogee spillway is calculated using the modified weir equation: If you’ve ever designed a concrete gravity dam,
: These calculate the water profile (upper nappe) and spillway shape (lower nappe) based on USBR standards.
Piers and abutments cause flow contraction, reducing the effective crest length. If ignored, this could lead to overtopping and failure. According to USACE EM 1110-2-1603 guidelines, the effective length ( L_e ) is calculated as: