Hydraulic Design of Labyrinth Weirs: On-Demand

Labyrinth weirs are widely used in spillway rehabilitation to upgrade existing dams to meet updated spillway design flood criteria. In addition to increasing discharge capacity, these weirs are also well suited to regulating upstream pool elevations for flood control or at intake structures. The hydraulic design of a labyrinth spillway requires the consideration of complex flow characteristics and optimization of multiple geometric parameters in an iterative process. In addition to maximizing hydraulic performance, other considerations must be taken into account (e.g., site characteristics, construction costs, and operational objectives and requirements) when designing a labyrinth weir control structure.

During the past 10 years, considerable research has been performed at Utah State University on the hydraulics of labyrinth weirs. This webinar presents the application of the resulting design methodology, information, and guidance used to develop effective labyrinth spillway designs. Technical components include the influence of labyrinth weir geometry (sidewall angle and crest shape) on discharge efficiency, in-channel and reservoir-specific labyrinth weir applications, nappe interference, nappe behaviors, tailwater submergence effects, staged labyrinth weir hydraulics, high headwater ratios, downstream residual energy, generalized spillway construction costs, and a comparison between labyrinth spillways and a similar spillway type, the piano key weir.

Blake Tullis

Professor, Utah State University

Blake Tullis is an associate professor at Utah State University (Civil and Environmental Engineering.  He conducts hydraulic structures research at the Utah Water Research Laboratory in the areas of labyrinth and piano key weirs, weir submergence, culvert hydraulics, and fish passage.  He has published 26 peer-review journal articles, 41 conference publications, 6 book chapters, and 1 book.  Blake teaches courses on hydraulic structure design, pipeline hydraulics, and fluid mechanics. 

Brian Crookston, Ph.D., P.E.

Schnabel Engineering/Senior Engineer

Brian Crookston, PhD, PE is a Senior Engineer and Water Resources Technical Discipline Coordinator with Schnabel.  His primary role is as an H&H technical resource for dam and levee projects company-wide.  He has particular interests in water conveyance, hydraulic structures, and dam safety, including spillway hydraulics, flow acoustics, debris, energy dissipation, physical and numerical modeling, and design optimization.  


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4 Questions
4 Questions Post Survey
Completion Quiz
10 Questions  |  3 attempts  |  6/10 points to pass
10 Questions  |  3 attempts  |  6/10 points to pass
Completion Certificate
2.00 PDH credits  |  Certificate available
2.00 PDH credits  |  Certificate available