Rollin Hotchkiss

Brigham Young University - Provo Main Campus | BYU · Department of Civil and Environmental Engineering

Sediment accumulation in reservoirs across the world diminishes reservoir benefits, increases maintenance costs, and damages the environment. United States regulatory policy requires State and Federal permits for discharging sediment into waterways, which has tended to discourage alternatives that pass sediment downstream of the dam. The cost of me...

For fishes, swimming performance is an important predictor of habitat use and a critical measure for the design of effective fish passage systems. Few studies have examined burst and prolonged types of swimming performance among several co-occurring species, and swimming performance in many fish communities is undocumented. In this study, we charac...

Bathymetric mapping is an important tool for reservoir management, typically completed before reservoir construction. Historically, bathymetric maps were produced by interpolating between points measured at a relatively large spacing throughout a reservoir, typically on the order of a few, up to 10, meters or more depending on the size of the reser...

Computer simulation of reservoir sediment management strategies is becoming more important as worldwide water supply shrinks due to sediment deposition, while population growth continues. We identified the physical processes underlying each of the several alternatives available to transport incoming or deposited sediments downstream into receiving...

Culverts can provide a significant barrier to fish passage by fragmenting fish habitats and impeding the passage success of small-bodied fish. Geographical connectivity is critical to the maintenance of diverse fish assemblages. Culverts with high cross-sectional velocity can cause population fragmentation by impeding passage of small, freshwater f...

Low-head dams are capable of creating dangerous countercurrents just downstream from the structure. These dangerous countercurrents are known as submerged hydraulic jumps and are responsible for hundreds of fatalities at numerous low-head dams across the United States. The countercurrent creates high upstream-directed surface velocities across the...

The performance of seven sediment transport equations for bedload transport is compared using almost 2,600 of more than 8,000 measurements from a recent compilation. Named equations tested include the Meyer-Peter Muller, Barry, Pagosa good condition, Wilcock, Parker (both calibrated and uncalibrated), Recking, and that of Elhakeem and Imran. The pu...

Our nation’s reservoirs are filling with sediment that deposits in and upstream from dams. Dam owners, whether be governmental, commercial, or private, will be faced with the issue of managing reservoir sedimentation issues in the not-too-distant future. Six brief case studies of how sediment is managed illustrate the diverse and complex nature of...

Our nation's reservoirs are filling with sediment that deposits in and upstream from dams. Dam owners, whether be governmental, commercial, or private, will be faced with the issue of managing reservoir sedimentation issues in the not-too-distant future. Six brief case studies of how sediment is managed illustrate the diverse and complex nature of...

The processes involved in bed-load sediment transport are complex and difficult to quantify. Field measurements provide insight and a chance to improve predictive methods. A comprehensive database is described that contains more than 15,000 observations from nearly 500 data sets of bed-load sediment transport. Observations are compiled from publish...

Despite mounting demand for a more sustainable worldwide water supply system, available reservoir capacity is relentlessly diminishing due to sedimentation. Neither sustainable reservoir life spans nor intergenerational equity is achieved through conventional cost-benefit analyses (CBAs), which render all benefits and costs projected to occur more...

Millsite Dam, closed in 1971, is typical of the hundreds of NRCS dams constructed in the United States. Built for water storage, the original 18,000 acre-ft of storage has been reduced by about 3,000 acre-feet due to reservoir sedimentation. The nature of sediment deposition in reservoirs is such that most sediments deposit in the active pool rathe...

Low-head dams can cause dangerous currents near the downstream face of the structure. Fatalities at low-head dams with such currents, often referred to as “drowning machines,” are poorly documented. This technical note presents a new database of fatalities at low-head dams in the United States together with an interactive map and web-based user int...

In this article, we present the results of the analysis of a flood event that occurred on 18 July 2008 in the town of Tlaltenango, Zacatecas, Mexico. The flood was caused by a storm that reached an accumulated precipitation of 145 mm/day. The event was caused by the passage of hurricane Fausto that produced an intensification of moisture transport...

Current economic analyses of reservoirs are not conducive to sustainable lifespans or intergenerational equity. The reason is shown to be the traditional application of cost-benefit analyses (CBA), which renders any benefits more than a few decades into the future negligible due to the use of constant discount rates. As a result, most future costs,...

Culvert design requirements have evolved with our ability to analyze the complex hydraulics associated with culvert flow. Simple nomograph solutions have been supplemented with comprehensive software, such as HY-8 and HEC-RAS, and tools to evaluate fish passage, such as FishXing. Designing culverts solely for clear water solutions is insufficient....

We introduce a sinusoidal perturbation to stream channel width in an otherwise uniform, rectangular channel. A first-order Taylor series of the perturbed equations of motion applied to a hypothetical case study show that the maximum scour depth migrates downstream with increasing discharge and the location for maximum scour at bankfull depth is clo...

By trapping sediment in reservoirs, dams interrupt the continuity of sediment transport through rivers, resulting in loss of reservoir storage and reduced usable life, and depriving downstream reaches of sediments essential for channel form and aquatic habitats. With the acceleration of new dam construction globally, these impacts are increasingly...

Current culvert design standards for fish passage compare sustained swimming abilities of the target fish species with a cross sectional area based average flow velocity through the culvert. Such policies dictate relatively large culvert barrels and do not recognize the significant role of reduced velocity zones in the culvert near boundaries. Test...

There is a school of thought regarding the prediction of bedload transport which relies on prolific amounts of data fitted by regression curves that capture the physical processes of bedload transport.Acompelling argument against this school of thought is that the use of regression curves do not account for or explain the physics known to be drivin...

To predict hydraulic jump characteristics for channel design, jump height may be determined by calculating the subcritical sequent depth from momentum theory. In closed conduits, however, a hydraulic jump may fill the conduit entirely before the expected sequent depth is reached. This paper reviews momentum theory as applicable to closed-conduit hy...

Empirically based lumped hydrologic models have an extensive track record of use for various engineering applications. Physically based, multi-dimensional distributed models have also been in development and use for many years. Despite the availability of high resolution data, better computational resources and robust, numerical methods implemented...

The Federal Highway Administration has developed new guidance for the design of culverts to facilitate aquatic organism passage (AOP). The guidance is provided in Hydraulic Engineering Circular (HEC) 26 "Culvert Design for Aquatic Organism Passage." The basis of the design approach is to provide hydraulic conditions within an embedded (or open-bott...

Potamodromous fish are poorly studied even though they are threatened often by human activities. The one sucker (Chasmistes horns) is an endangered potamodromous species endemic to Utah Lake. Larval June suckers have not been collected from Utah Lake for at least 3 decades. Recruitment appears to be limited by low temperatures and scarce food, resu...

Small-to-medium sized reservoirs are critical to providing water storage capacity for water supply agencies. These reservoirs provide many services, including irrigation, drinking water and other municipal uses, hydropower, environmental enhancements, recreation, and flood control. A reservoir is constructed knowing that, sooner or later, it will f...

In order to predict hydraulic jump characteristics for channel design, jump height may be determined by calculating the subcritical sequent depth from momentum theory. In closed conduits, however, a hydraulic jump may fill the conduit entirely before the expected sequent depth is reached, resulting in the aptly-named "incomplete" jump. This require...

Sediment transport through culverts is poorly understood. Current design methods for culverts are generally based on the characteristics of open channel flow. A careful analysis of previous studies reveals significant differences between open channel flow and flow through a culvert. The purpose of this paper is to identify and categorize the main d...

The alarming loss of water storage capacity to sedimentation in reservoirs worldwide is prompting a paradigm shift toward sustainable management. Previous research has investigated the physical capability of various technologies to control reservoir sediment, and formulated economic rules governing their optimal sustainable use. We ask the next rel...

A present and future challenge for water resources engineers is to extend the useful life of our dams and reservoirs. Ongoing reservoir sedimentation in impoundments must be addressed; sedimentation in many reservoirs already limits project benefits and effective project life. Sustainability requires that incoming sediment be moved downstream past...

Design methods that account for the ability of fish to swim upstream through culverts are based on tests describing how fast and for how long different fish species can swim. These methods are based on an average water velocity but fail to recognize that fish can take advantage of resting places and non-uniform flow in culverts. Culverts that are d...

Culverts throughout the country are approaching or are past their original design lives. These `baby boomer' culverts will need to be repaired, rehabilitated, or replaced. Because entire culvert replacement is so expensive and intrusive, alternate measures to extend the culvert project life are growing increasingly popular. One such method is slip...

Baffles are often used to retrofit culverts to aid in fish passage. The objective of this experimental investigation was to compare the turbulent flow structure inside a full-scale spiral corrugated culvert fitted with sloped- and slotted-weir baffles to available turbulence descriptions for non-baffled culverts. In addition, the turbulent flow str...

Several computer programs are available to analyze culvert hydraulics, including HY-8, FishXing, Broken-back Culvert Analysis Program (BCAP), Hydraflow Express, CulvertMaster, Culvert, and Hydrologic Engineering Center River Analysis System (HEC-RAS. The use of slightly different methodologies to complete the analysis results in different estimates...

Culverts throughout the country are approaching or are past their original design lives. These 'baby boomer' culverts will need to be repaired, rehabilitated, or replaced. Because entire culvert replacement is so expensive and intrusive, alternate measures to extend the culvert project life are growing increasingly popular. One such method is slip...

Although civil engineers continually develop new ways to solve problems involving water, energy, infrastructure and environmental sustainability, these innovations can take years - or even decades - to reach, developing countries. Computer-based instruction has the potential, to dramatically decrease this lag time by improving engineering education...

Accurate flow field measurements in shallow rivers are necessary for many applications including biological investigations and numerical model development. Unfortunately, river velocity data is difficult to obtain due to the limitations of traditional velocity meters. Acoustic Doppler Current Profilers (ADCP) provide a potential alternative to trad...

The potential impacts of climate change on water yield are examined in the Upper Wind River Basin. This is a high-elevation, mountain basin with a snowfall/snowmelt dominated stream-flow hydrograph. A variety of physiographic conditions are represented in the rangeland, coniferous forests, and high-elevation alpine regions. The Soil Water Assessmen...

This article describes a prototype modeling system for assessing forest management-related erosion at its source and predicting sediment transport from hillslopes to stream channels and through channel networks to a watershed outlet. We demonstrate that it is possible to develop a land management tool capable of accurately assessing the primary imp...

Several software programs have been developed to assist in the hydraulic design and analysis of culverts. Of the available programs, HY8 is the most widely used and distributed. The first version of HY8 was provided by the Federal Highway Administration (FHWA) for distribution in the 1980s. Since that time, understanding of culvert hydraulics has i...

Research at Washington State University is bringing together state-of-the-art and state-of-practice fish passage design criteria from across the nation - covering culvert and bridge installations or retrofits. A Federal Highways manual entitled Hydraulic Engineering Circular 26 “Design of Fish Passage at Bridge and Culverts” (HEC-26) will be the am...

This paper presents results of an experimental investigation to increase roughness within the barrel of a concrete box culvert using trapezoidal-shaped corrugations with a shape similar to pavement underlay on bridge decks. Half-scale corrugations were placed on the bottom and both sides of a tilting flume 21 meters long, 0.90 meters wide, and 0.53...

Improving descriptions of natural stream flow fields is a critical step in restoring aquatic ecosystems. Current methods used for evaluating aquatic habitat rely on simplified representations of the flow field. These methods can be improved by incorporating important spatial and temporal flow field variations and more advanced habitat metrics. Howe...

Recent evidence suggests that, although their ultimate destination is the sea, juvenile salmonids also travel upstream to locate more desirable habitat and feeding areas. Since many culverts are impassible to juvenile salmonids, baffle systems are being evaluated that will facilitate greater upstream passage. A culvert test bed facility at Washingt...

The problem of culverts that block fish from freely moving up and downstream is becoming a critical environmental issue. Agencies often retrofit culverts with baffles to aid in fish passage, but little is known about the detailed flow characteristics within a baffled culvert. During August and September, 2005, fine-scaled measurements were taken at...

We analyze the economic dynamics of reservoir sedimentation management using the hydrosuction-dredging sediment-removal system. System dynamics depend on two interdependent hydraulic processes evolving at different rates. The accumulation of water impounded in the reservoir evolves on a ‘fast’ time scale, while the loss of water storage capacity to...

The loss of the world's reservoir capacity to sedimentation can be mitigated by altering dam operations to release sediment downstream. However, legal uncertainty regarding whether dam owners are liable for damages to surrounding landowners due to altered operations provides a significant disincentive for sustainable sediment management. Past work...

An acoustic Doppler velocimeter was used to characterize turbulence in two gravel bed rivers. Data were collected in unobstructed flow and compared to recent investigations. Additional data collected in the wake of emergent boulders indicate that mean flow velocity, turbulent kinetic energy, gradients in the streamwise velocity, and Reynolds stress...

Disturbance is known to be a dominant variable in stream ecology. Disturbance can be the result of hydraulic or physical modifications to the environment. Periphyton assemblages are composed of attached algae, bacteria, and fungi growing on the streambed. The assemblages can be viewed as a necessity or a nuisance depending on stream productivity. P...

Global climate change will likely modify the availability of surface and ground water. It is necessary to evaluate the potential impacts of climate change on water resources to assist in policy decisions. Water resources impact assessments are often completed with hydrologic models. This draws into question the temporal and spatial scales over whic...

In 2000, the first author presented a report on the ability to simulate a swimming fish using numerical solutions to the equations of motion. This paper is a report of significant progress towards the solution of this complex problem. The propulsion mechanism of a 10 cm rainbow trout (oncorhynchus mykiss) swimming steadily in undulatory mode was in...

Experiments were performed to investigate the energy dissipation realized at the outlet of a culvert using two simple design alternatives: (1) Design I, a simple weir near the culvert outlet, and (2) Design II, a weir with a drop upstream in the culvert outlet barrel. The two designs are intended to reduce the flow energy at the outlet by inducing...

The Federal Highways Administration and Washington State University are collaborating to produce Hydraulic Engineering Circular 26: "Design of Fish Passage for Bridges and Culverts"; a comprehensive manual for the design or retrofit of a stream crossing to meet fish passage requirements. Input from State Departments of Transportation, non-governmen...

Riprap and concrete stilling basins are often built at culvert outlets to keep high-energy flows from scouring the streambed. Two simple alternatives to large basins are examined: a horizontal apron with an end weir and a drop structure with an end weir. The two designs are intended to reduce the flow energy at the outlet by inducing a hydraulic ju...

Riprap and concrete stilling basins are often built at culvert outlets to keep high-energy flows from scouring the streambed. Two simple alternatives to large basins are examined: a horizontal apron with an end weir and a drop structure with an end weir. The two designs are intended to reduce the flow energy at the outlet by inducing a hydraulic ju...

The propulsion mechanism of an undulatory swimming 10 cm rainbow trout (oncorhynchus mykiss) is studied using a laminar 2-D unsteady incompressible Navier-Stokes computational model with a moving adaptive mesh (Fluent 6.1). The wake mechanism is dominated by a reverse von Karman vortex street and compares well to previous experimental data. Thrust...

The Albrook Hydraulics Laboratory was constructed literally around an early physical model at the Washington State University Pullman campus. Since the first model study approximately fifty years ago, the laboratory facility was enlarged two more times as a response to the growing demand for model studies with the expansion of hydroelectric project...

Spillways at dams on the Columbia River and main tributaries are of the tainter-gate type, which discharge water beneath the gate structure when open. An experimental overflow weir was installed in one of the Lower Granite Dam (LGD) spillway bays in the Snake River in the Fall of 2001. Called the Removable Spillway Weir, or RSW, its purpose is to t...

The Washington Department of Fish and Wildlife recently established statewide guidelines for incorporating adult fish migration into culvert design. One of the design options requires an estimate of fish passage design flow for ungaged culvert sites. A new model is presented for estimating fish passage design flows at ungaged sites in Eastern Washi...

1] Water yield responses to two climate change scenarios of different spatial scales were compared for the Missouri River Basin. A coarse-resolution climate change scenario was created from runs of the Commonwealth Scientific and Industrial Research Organization General Circulation Model (CSIRO GCM). The high-resolution climate change scenario was...

A broken-back culvert has one or more changes in grade within the prismatic barrel profile. One section of a broken-back culvert is usually steep, with the steep slope contributing to high outlet velocities unless a hydraulic jump forms upstream from the culvert outlet. Predictive equations have been published for a wide range of experimental condi...

The turbulent flow fields in the wakes of several boulders were characterized using an Acoustic Doppler Velocimeter (ADV). The boulders were located in the Clearwater and the Lochsa Rivers in Idaho. The purpose of this research was to add to the body of river turbulence data and to use the information to assist in juvenile salmonid passage at dams....

An Acoustic Doppler Velocimeter (ADV) was used to characterize turbulence downstream from a boulder in the Clearwater and the Lochsa Rivers in Idaho. The purpose of this research was to add to the body of river turbulence data and to use the information to assist in juvenile salmonid passage at dams. Measurements were taken with a Sontek Field ADV...

The soil water assessment tool (SWAT) is a hydrologic model originally developed to evaluate water resources in large agricultural basins. SWAT was not designed to model heterogeneous mountain basins typical of the western United States, and as a result, has performed poorly when applied to mountainous locations. The intent of this study was to inc...

Flow over a sharp-crested weir can create dangerous countercurrents downstream under high tailwater conditions. A comprehensive experimental design project in open-channel hydraulics used in a senior/graduate course and in a freshman exploratory experience is illustrated. This applied problem allows the instructor to demonstrate hydraulic jumps, ae...

Washington State University, by virtue of the presence of the Albrook Hydraulics Laboratory, maintains several courses devoted to hydraulic engineering. The evolution of hydraulics offerings reflects the needs of the day. Fluid mechanics was emphasized following the World War II dam construction boom, including hydraulic structures and water hammer...

A broken-back culvert has one or more breaks in profile slope and is most often used in areas of high relief and steep topography. The usual broken-back configuration begins with a relatively flat slope followed by a steep slope and a very flat "runout" section. Because of the steeply sloped portion of the culvert, outlet velocities in the absence...

Water from the Missouri River Basin is used for multiple purposes. The climatic change of doubling the atmospheric carbon dioxide may produce dramatic water yield changes across the basin. Estimated changes in basin water yield from doubled CO2 climate were simulated using a Regional Climate Model (RegCM) and a physically based rainfall-runoff mode...

Global climate changes caused by increased atmospheric concentrations of carbon dioxide (CO2) and other greenhouse gases will change patterns of water yield. Increases in CO2 affect water yield through changes in temperature, precipitation, runoff, and evapotranspiration (ET). The Soil and Water Assessment Tool (SWAT) was applied to five watersheds...

Future computational codes will be capable of simulating the movement of a single fish through moving fluid. Present codes can simulate (1) turbulent flow around stationary objects (hydraulic models); (2) flow around a moving foil attached to a wing in unidirectional flow; (3) the changes in pressure and turbulent kinetic energy on a "virtual fish"...

The hydrological response due to potential CO,~forced climate change in the Black Hills of South Dakota was investigated using modelling techniques that include variations to atmospheric CO,, temperature, and precipitation. The Soil and Water Assessment Tool (SWAT) was used to model the 427 km2 Spring Creek basin hydrology and simulate the impact o...

Procedures were developed and tested for quantifying seepage losses in unlined irrigation canals for reaches on the order of 100 ft (30 m). The procedure is appropriate for trapezoidal canal sections underlain by clay with a layer of more permeable material at depth. These conditions prevail throughout much of the Central Nebraska Public Power and...

Bed stability and morphology in countersunk culverts on steep slopes were examined to improve understanding of the parameters governing sediment flow characteristics in mountain streams. The knowledge gained was used to provide preliminary construction guidelines for the stream simulation approach of countersunk culverts, an approach that is under...