Civil and Environmental Engineering Commons^™

Value Added 3d Modeling – Lower Crow Dam Spillway Modification And Rehabilitation Project, Justin Bartels

4th International Workshop on Labyrinth and Piano Key Weirs

The Confederated Salish and Kootenai Tribes (CSKT) have been operating Lower Crow Dam under restricted reservoir levels since 2008 due to significant structural and spillway capacity deficiencies that have increased risk to dam safety. Stantec was contracted by the CSKT to evaluate rehabilitation options and provide final design for the new spillway. The focus of this paper is to describe the design methodology and spillway selection process with an emphasis on the hydraulic modeling completed to support the final spillway arrangement. The design approach included the evaluation of various spillway types including gated, Obermeyer, fuse gate, ogee, labyrinth, and piano …

Design Approach For Labyrinth Weir: Case Study Of La Laye Dam, M. Roy, S. Derrien, J. Schaguene, G. Dautois

4th International Workshop on Labyrinth and Piano Key Weirs

This paper presents ARTELIA’s gradual approach for the design and construction of labyrinth weirs, from the preliminary concept design to the commissioning. It is illustrated with the case of La Laye dam, where an additional lateral spillway with labyrinth weir has been developed to increase the existing discharge capacity. The design process involved preliminary hydraulic calculations, 3D numerical modeling and a physical scale model. The paper elaborates on the technical solutions and optimizations which were considered to provide the Client with the most hydro-economical solution.

Advances In Arced Labyrinth Weir Research And Application At The Springton Spillway Project, Seth Thompson, Blake Tullis, Brian M. Crookston

4th International Workshop on Labyrinth and Piano Key Weirs

Arced labyrinth weirs, characterized by a curved cycle orientation, can enhance discharge efficiency compared to linear labyrinth weirs by taking advantage of the approaching flow field in reservoirs. This paper summarizes some of the Utah State University arced labyrinth weir hydraulic efficiency research findings, including sidewall and cycle arc angle influences, nappe aeration, and local submergence. Recent CFD modeling that replicates some of the experimental findings is also highlighted, demonstrating CFD utility for design. The Springton Spillway project, owned by Aqua Pennsylvania, leveraged this research when designing a two-stage, eight-cycle arced labyrinth weir to replace an aging ogee crest spillway …

Piano Key Weir With Orifice Sluice, Dau Xuan Thuy

4th International Workshop on Labyrinth and Piano Key Weirs

In recent years, many Piano Key Weirs (PKW) have been built around the world. In Vietnam there are more than 18 PKWs in operation to the present. However, during the operation, some experience has been drawn on the design and application conditions. This paper is about the Dak Mi 3 reservoir with a PKW that operated well for more than 4 years until an exceptional flood following typhoons in October 2020, making reservoir fully filled with mud and sand. The result is the PKW became ineffective and the hydropower plant unable to operate. In order to dredge the reservoir and …

Honey, I Shrunk The Pk Weir: A Case Study Of Burton Pond Dam, David Bisio

4th International Workshop on Labyrinth and Piano Key Weirs

Between a low-head tidal environment, razor-thin hydraulic margins, and a long list of site restrictions, the Burton Pond Dam Rehabilitation project offered the chance to pursue a one-of-a-kind solution: a miniature stainless steel piano key weir as part of a new mixed active-passive spillway. This case study will explore how established hydraulic designs were modified specifically for the site and verified with computational flow dynamics; how the innovative cantilevered geometry was analyzed structurally with finite element modeling; and how detailing, fabrication and constructability were considered throughout the design process. From conceptual-level design submissions to the final construction walkthrough, the whole …

Research And Application Of Piano Key Weirs In Vietnam (2025), M. Ho Ta Khanh, Dau Xuan Thuy

4th International Workshop on Labyrinth and Piano Key Weirs

Since the Piano Key Weirs (PKW) were introduced by F. Lempérière and A. Ouamane (2003) many such structures have been built for irrigation, hydroelectricity and water regulation due to their outstanding efficiency. In Vietnam, PKWs have also attracted significant attention. There have been several laboratory hydraulic model studies to test the discharge capacity, flow characteristics, and energy dissipation downstream the spillway. Vietnam had also issued PKW design standard for easy of application in 2018. This paper describes shortly 18 Piano Key Weirs in operation in Vietnam (among other existing PKWs) : Dak Mi 4B, Dak Mi 3, Dak Rong 3, …

Lessons Learned From The Hydraulic Design Of The Prado Dam Labyrinth Spillway, Yajayra Diaz, Mike Phillips, Brian M. Crookston, Julie D. Allen

4th International Workshop on Labyrinth and Piano Key Weirs

The U.S. Army Corps of Engineers has completed the design of a new labyrinth weir spillway at Prado Dam, in southern California. The proposed labyrinth weir would consist of an arced configuration, 7-cycles, with varying weir wall height from 28 ft to 41 ft with upstream head over the weir cycles of up to 30 ft. This paper highlights the key lessons learned from the hydraulic design of the new labyrinth weir, including significant fluctuating negative pressures at the weir wall resulting in hydrodynamic loads that should be considered during structural design and submergence of the weir at high heads.

Investigation Of Flow Field Near A Type-A Piano Key Weir, S. Hussain, M. S. Quamar, Z. Ahmad

4th International Workshop on Labyrinth and Piano Key Weirs

Piano Key Weirs (PKWs) enhance spillway capacity and induce complex flow patterns around their inlet and outlet keys. This study investigates the flow near a Type-A PKW using Computational Fluid Dynamics (CFD). Velocity fields in the vicinity of the PKW keys were analyzed for different discharges and validated with the experimental results. As flow approaches the inlet key, the streamwise, vertical, and lateral velocity components increase significantly, with the highest velocities near the inlet key. However, near the outlet key the streamwise velocity decreases while the vertical and lateral components increase. For all the discharges, the maximum velocity was observed …

Key Width Ratio Influence On Discharge Coefficients Of Trapezoidal Piano Key Weirs Via Openfoam Simulations, Lisa Lüddecke, Mario Oertel

4th International Workshop on Labyrinth and Piano Key Weirs

Piano key weirs are characterized by complex three-dimensional flow structures with multiple parameters describing their geometry. The variation of these parameters can affect several flow characteristics such as efficiency, energy dissipation and air entrainment. Identifying the optimal geometry for enhanced hydraulic performance represents a significant challenge. Physical or numerical modeling of multiple geometric variants is necessary to identify the relevant optimal parameters. The key width ratio (between an inlet and an outlet key) represents one of the parameters that influences the hydraulic behavior of the piano key weir. In particular, it affects the discharge coefficient, which in turn affects the …

Experimental And Numerical Investigation Of A-Type Rectangular Side Piano Key Weir, Sabir Hussain, Zulfequar Ahmad

4th International Workshop on Labyrinth and Piano Key Weirs

A side weir is a structure installed along the side wall of a channel, serving multiple purposes, such as raising water levels for irrigation and drainage and diverting excess flow from rivers or channels during floods. Most studies have focused so far on linear rectangular and labyrinth side weirs, with relatively limited research conducted on side Piano key weirs. In this paper, an experimental and numerical simulation was performed on an A-type rectangular side piano key weir and a rectangular sharp-crested side weir. The diversion discharge of Piano key side weirs was within the range of ± 10% with numerical …

Sensitivity Analysis Of Piano-Key Weirs Design: Optimizing Discharge Performance Through Cfd Modeling And Empirical Insights, Fatna Oukaili, Yvan Bercovitz, Thomas Fonty, Benoit Blancher, Julien Vermeulen

4th International Workshop on Labyrinth and Piano Key Weirs

Piano-key weirs (PKWs) are widely recognized for their efficiency in enhancing spillway discharge capacity while maintaining a compact footprint. This study focuses on a parametric and sensitivity analysis of PKW discharge performance, exploring the influence of key design parameters on hydraulic behavior. By integrating experimental data with advanced computational fluid dynamics (CFD) modeling using the open-source code_saturne software, we aim to refine predictive capabilities and establish guidelines for effective PKW design. The analysis emphasizes understanding the interplay between PKW geometry and flow characteristics. The analysis considers a range of geometrical configurations, including variations in key width ratios, and inlet-to-outlet dimensions, …

An Innovative Use Of Piano Key Weirs Or Labyrinth Weirs For Long Dams In Plains, Michel Ho Ta Khanh

4th International Workshop on Labyrinth and Piano Key Weirs

Piano Key Weirs (PKW) are labyrinth type weirs but with upstream and/or downstream overhangs which allow them to have a reduced footprint at their base. The new solution of a combination of gates and PKW (or labyrinth weir) for a long dams has many advantages of costs for investment, operation and safety during high floods. If a new dam is built on a broad river where a large footprint is possible, the choice between a PKW and a labyrinth weir can arise as the difference of specific discharges of the two alternatives are relatively small and the construction of the …

An Innovative Association Of Fusegate And Pk-Weir, F. Lempérière, A. Chapuis, F. Del Rey, C. Bessière

4th International Workshop on Labyrinth and Piano Key Weirs

The combination on the same dam of Piano Key weir (PK-Weir) and fusible structures offers a highly effective passive solution for managing flood discharges. This concept first introduced by Hydrocoop in 2015 as « Innovative Associated Spillways » can leverage the strength of each system. More than 30 years after its first application, the returns of experience of the Hydroplus Fusegate® system applications on more than 80 dams in 25 different countries have confirmed their reliability in terms of sequentially overturning on the downstream side for the correct design flood. With their high discharge capacity at low head, PK-Weirs optimize …

Enhancing The Hydraulic Efficiency Of Piano Key Weir (Pkw) — Some Research Achievements, James Yang, Shicheng Li, Anders Ansell, Erik Skepparkrans, Chen Lin

4th International Workshop on Labyrinth and Piano Key Weirs

As an effective flood control structure, the piano key weir (PKW) typically features a rectangular planform for its overhangs. However, this design offers room for improvement. To enhance hydraulic efficiency, two modified PKW layouts are proposed. In the first, the floor of each key is lowered with a semicircular cross-section, forming an elliptical planform and crest. In the second, the floor is lowered with an isosceles triangular prism, creating an equilateral triangular overhang. Both modified PKW models, manufactured by 3D printing, were tested in a large-scale experimental setup. Compared to the reference weir, the elliptical-overhang PKW increases the developed crest …

Theoretical And Experimental Studies Of Non-Rectilinear Weirs -From Labyrinth To Pk-Weir, Ahmed Ouamane, François Lempérière

4th International Workshop on Labyrinth and Piano Key Weirs

Free-flow rectilinear spillways, while simpler and safer than gated or shaft spillways, have a low specific discharge, requiring a significant water head and resulting in a storage loss of more than 20% for some small reservoirs. To overcome this drawback, labyrinth weirs provide an effective alternative, allowing high discharge under a reduced head while maintaining lower construction and maintenance costs. For several decades, global research has focused on optimizing their design. In this context, a research project was initiated in 1995 at the University of Biskra to enhance the understanding of the hydraulic behavior of these structures. This project was …

Physical Model Investigations On Nappe Instabilities At Labyrinth Weirs, Michael Gebhardt, Fabian Belzner

4th International Workshop on Labyrinth and Piano Key Weirs

Free overflow hydraulic structures operating at low heads tend to develop nappe instabilities when there is no ventilation. A detailed investigation has been undertaken with a relatively large-scale labyrinth weir in the hydraulic laboratory of the BAW. A quarter-round crest was selected, because nappe instabilities mainly occur at sharp-crested weirs, which favor the development of an air pocket behind the nappe. The headwater ratios for which nappe instabilities could be observed were determined. Pressure fluctuations were measured and the frequencies determined. Adding splitters to the crest is one way to vent the air pocket and to avoid vibrations. Another possibility …

Model-Prototype Upscaling Of Pkw Discharge Capacity, James Yang, Pär Nilsen, Mats Billstein, L Johnsson, Shicheng Li

4th International Workshop on Labyrinth and Piano Key Weirs

In Sweden, many dams are undergoing upgrades to comply with the revised dam safety guidelines, which mandate higher spillway discharge capacities that their existing ones. As part of an ongoing project, a piano key weir (PKW) is proposed to replace an embankment dam and simultaneously increase the facility’s discharge capacity. The PKW configuration is evaluated in a 2 m wide flume at two geometric scales (1:35 and 1:12) to assess potential scale effects. The former comprises eight units, while the latter includes three, with all components produced using 3D printing. Results indicate that the 1:35 model exhibits a slightly lower …

Interfacial Velocity Characteristics Downstream Of A Piano Key Weir Versus A Linear Weir In A Horizontal Channel, Biruk Belay, Mario Oertel

4th International Workshop on Labyrinth and Piano Key Weirs

The downstream flow characteristics of piano key weirs (PKWs) are highly complex, manifested by significant localized self-aeration due to nape collisions and plunging jets impacting the downstream free-surface. For PKWs installed in horizontal channels, the interfacial velocity characteristics have received limited attention in previous research. In this experimental study, air-water flow measurements were conducted using a double-tip conductivity probe downstream of a PKW and a reference ogee-crested linear weir to evaluate the velocity trends under comparable hydraulic boundary conditions. The findings reveal the existence of two distinct velocity profiles downstream of piano key weirs: quasi-wall-jet and uniform profiles. The occurrence …

Effect Of Driftwood On The Hydraulic Performance Of A-Type Piano Key Weirs Situated In-Stream Or At Reservoirs, Pascal Venetz, Michael Pfister

4th International Workshop on Labyrinth and Piano Key Weirs

Driftwood is a natural part of most river ecosystems. The knowledge of its interaction with hydraulic structures, such as PKWs, is essential for two reasons: To (1) avoid uncontrolled inundations because of the level rise initiated by trapped driftwood (reducing the weir discharge coefficient), and (2) initiate the passage of the wood over the PKW, so that it remains in the river to further fulfill its environmental services. Knowledge of the conditions motivating driftwood to block at a PKW is essential. The present study accordingly focuses on the blocking probability of driftwood at PKWs and the resulting head increase – …

Floating Trees At Co-Existing Pkw & Gated Spillway, James Yang, A. Helgesson, L. Johnsson, Sc Li

4th International Workshop on Labyrinth and Piano Key Weirs

During extreme flood events, floating trees (driftwood) can pose serious risks to the safety and operation of dams. In upgrading an existing dam, a piano key weir (PKW) is introduced to replace the aging embankment dam and to increase the discharge capacity of its gated spillway. This upgrade necessitates a detailed understanding of driftwood behavior at both discharge structures, which differ significantly in design and operating conditions. To investigate this, hydraulic model tests were conducted using small, freshly cut trees—some with branches and roots—to simulate natural trees moving towards the dam. The results indicate that tree accumulation at the gated …

Using Drone And Ai To Map Leaf Water Potential And Stem Water Potential For Water Stress Management In Commercial Vineyards, Alfonso F. Torres-Rua

Funded Research Records

No abstract provided.

Career: Flavones As Safe, Sustainable Additives To Tune Biodegradable Plastic Stability, Kyle Moor

Funded Research Records

No abstract provided.

Rapid: Data Collection On Roadway Vehicle Abandonment In The Fast-Moving Los Angeles Wildfire Evacuations, Sarah Grajdura

Funded Research Records

No abstract provided.

How Low A Colorado River Flow To Go? Insights From Numerically Stabilizing Lake Powell And Lake Mead During Crisis, David Rosenberg, Anabelle Myers, Motasem Abualqumboz, Erik Porse

Civil and Environmental Engineering Faculty Publications

Colorado River users are now discussing dividing river flow on a percentage basis (Fleck, 2025; Hager, 2025, Winslow, 2025). This is an important step to managing a declining and more volatile supply. In our prior May 2025 post, we shared a strategy we have worked on for several years— division of river flow—as one of 13 reasons why we have hope for consensus on Colorado River management. In this post, we address the question: How extreme low river flow and reservoir storage should we plan for going forward (Figure 1)? We also share our insights from numerically stabilizing and recovering …

Pressure Recovery Analysis Downstream Of Valves And Meters: An Experimental And Numerical Investigation, Stephen J. Sanders

All Graduate Theses and Dissertations, Fall 2023 to Present

In pressurized water systems, flow control devices such as valves and meters cause pressure losses that can affect energy efficiency and measurement accuracy. Industry standards assume that all devices recover within the same distance downstream, but this may not be true for all device types. In this study we used laboratory testing and computer modeling to determine how far downstream pressure stabilizes after flowing through various valves and meters. Devices like Venturi meters recovered pressure quickly, while orifice plates required longer distances and resulted in greater permanent energy loss. In most cases, pressure recovered within four to six pipe diameters. …

Assessing Public Satisfaction And Transportation Choices During Winter Road Maintenance: A Case Study Of Utah, Shailendra Khanal

All Graduate Theses and Dissertations, Fall 2023 to Present

Winter road maintenance is essential to keeping people safe and mobile during snowstorms. In Utah, where winter weather is a regular part of life, the Utah Department of Transportation (UDOT) plays a vital role in keeping roads clear and functional. While much attention is given to how roads are plowed and managed, there has been less focus on how the public experiences these efforts—and how the decisions to travel during storms are shaped by personal circumstances and perceptions.

This research sets out to understand two things: how satisfied people are with winter road maintenance, and what influences their transportation decisions …

A Computational Study On Impact Performance Of Concrete Barriers For Protecting Transportation Assets, Ashesh Pokhrel

All Graduate Theses and Dissertations, Fall 2023 to Present

Highway safety is a major concern as roads accommodate increasing numbers of vehicles, including large trucks and tractor-trailers. Concrete barriers are commonly used along highways and bridges to prevent accidents by redirecting vehicles and protecting important structures like bridge piers. However, their effectiveness depends on how well they withstand vehicle impacts, how they perform after being damaged in previous crashes, and how they protect bridge piers when space is limited. This research examines these issues using advanced computer simulations to better understand barrier performance and improve roadway safety.

The first part of this study reviews how researchers and engineers use …

Precision Agriculture Applications In Tart Cherries: Yield Mapping Technologies And Remote Sensing For Water Stress Estimation, Anderson Luiz Dos Santos Safre

All Graduate Theses and Dissertations, Fall 2023 to Present

Tart cherry is an important specialty crop in the United States, particularly in Utah where the area dedicated to tart cherry cultivation is larger than any other fruit grown in the state. However, growers face increasing challenges due to rising land prices, limited water availability, and extreme weather events. These factors make it essential to adopt new technologies that improve efficiency and sustainability. Precision agriculture, which uses data-driven tools to manage crops more effectively, can help address these challenges. However, most tart cherry orchards still rely on traditional practices due to a lack of specialized technologies for this crop. This …

Operationalizing Camera-Based Hydrologic Monitoring With Ai And Edge Computing: Towards Real-Time Water Level And Discharge Measurements, Razin Bin Issa

All Graduate Theses and Dissertations, Fall 2023 to Present

Monitoring river water levels and flows is critical for managing water supplies, protecting against floods, supporting ecosystems, and informing infrastructure planning. However, traditional methods rely on sensors installed directly in rivers, which can be expensive, difficult to maintain, and vulnerable to damage—particularly in remote or hazardous locations. In many regions, limited budgets and access challenges result in large gaps in river monitoring networks.

This research explores an innovative alternative: using fixed cameras and artificial intelligence (AI) to monitor rivers from a distance. The approach allows for non-contact observation of water levels and flows by analyzing images captured by cameras installed …

Evaluating Cyanotoxins In Surface Water And Aerosols Near Utah Lake, Dylan R. Mcpeake

All Graduate Theses and Dissertations, Fall 2023 to Present

Utah Lake is a freshwater lake in Utah County near Provo, Utah. It is the third- largest lake in Utah and is important for recreation and local businesses. However, from June to October, the lake often has cyanobacteria harmful algal blooms (cHABs), which contain a toxin called cyanotoxin. These toxins can be dangerous to people who come into contact with the water. Government agencies regularly check for cHABs and warn people when the water is unsafe for activities like swimming. Collecting water samples to test for cHABs can be risky because it can possibly result in direct contact with the …