Segment V10.8: Low-Head Dam

(Related to Textbook Section 10.6.2 - Sharp-Crested Weirs)

Flow over a sharp-crested weir or a low-head dam can be quite complex and dangerous, especially if the flow contains a plunging nappe.

As shown in a model experiment involving flow over a low-head dam, it is possible to develop a "roller" on the down stream side of the dam from which it is difficult to dislodge floating objects. Items caught in this eddy tend to remain there. An appropriate change in the downstream geometry can be made to eliminate the hazards associated with the original design. (Video courtesy of U.S. Army Engineer Waterways Experiment Station.)