Controlled Spillways

---

A fuseplug emergency spillway (bottom) at the New Waddell Dam. (Wikipedia)

“A controlled crest is one that includes gates which are used to control the flow; the uncontrolled crest is one unencumbered by gates”. “Controlled spillways include crest gates that serve as a movable damming surface allowing the spillway crest to be located below the normal operating level of a reservoir or channel”.

“For controlled spillways that are not integral with a concrete dam (i.e., located away from the dam on or through abutments, or on or through reservoir rim), existing topography must provide adequate space without excessive excavation. Also, the existing topography must allow appropriate orientation (alignment of the spillway between the reservoir and downstream river or stream) of the conveyance feature and terminal structure. Additionally, economics will come into play for all controlled spillways”.

Types of Controlled Spillways

• Fuseplug Spillways
• Fusegate Spillways
• Gated spillways
• Siphon Spillway

Best Practices Resources

Design of Spillway Tainter Gates (EM 1110-2-2702) (U.S. Army Corps of Engineers)

Design Standards No. 14: Appurtenant Structures for Dams (Ch. 3: General Spillway Design Considerations) (Bureau of Reclamation)

Hydraulic Design of Spillways (EM 1110-2-1603)

Citations:

Revision ID: 4829
Revision Date: 12/02/2022