Many pathways of water can enter through a dam structure to produce a well-defined nappe. However, engineers classify dams as either overflow dams, where water consistently flows over or is blocked through a gate on top of crest, or non-overflow dams, which channel water through or around the dam with emergency flood gates. They both range in size.
Various routes of water can enter through a dam structure to create a well-defined nappe. However, engineers categorize dams as either overflow dams, where water consistently overflows or is blocked via a gate on top of the crest, or non-overflow dams, which direct water through or around the dam with emergency flood gates. Both types vary in size.