ASDSO Dam Safety Toolbox - User contributions [en]

Breach Parameters

2022-09-11T15:46:56Z

Pcampana: Created page with "__NOTOC__ ----  [Page Summary] “Performing a dam breach model involves prediction of the dam breach hydrograph and the routing of that hydrograph downstream. A number of modeling tools are available to perform dam breach modeling, ranging from simple methods to complex models. With advancements in GIS-based modeling, many models can interface with digital terrain data to..."

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[Page Summary]

“Performing a dam breach model involves prediction of the dam breach hydrograph and the routing of that hydrograph downstream. A number of modeling tools are available to perform dam breach modeling, ranging from simple methods to complex models. With advancements in GIS-based modeling, many models can interface with digital terrain data to produce automated dam breach inundation zone delineations.

“Dam breach modeling can be divided into two categories, each of which has a number of models, tools, or equations, ranging from simple to advanced: (1) tools that generate the dam breach peak discharge and/or hydrograph only; and (2) tools that develop a breach hydrograph and perform downstream flood routing using a one- or two-dimensional hydraulic model” <ref name ="FEMA P-946">[[Federal Guidelines for Inundation Mapping of Flood Risks Associated with Dam Incidents and Failures (FEMA P-946) | FEMA P-946 Federal Guidelines for Inundation Mapping of Flood Risks Associated with Dam Incidents and Failures, FEMA, 2013]]</ref>.

“The parameters of failure depend on the dam and the mode of failure, For flood hydrograph estimation, the breach is modeled assuming weir conditions, and the breach size, shape, and timing are the important parameters. The larger the breach opening and the shorter the time to total failure, the larger the peak outflow” <ref name ="EM 1110-2-1420">[[Hydrologic Engineering Requirements for Reservoirs (EM 1110-2-1420) | EM 1110-2-1420 Hydrologic Engineering Requirements for Reservoirs, USACE, 1997]]</ref>.

==Breach Parameter Definitions==

“The following definitions are commonly accepted for use in evaluating and selecting dam breach parameters:
* Breach formation time (also time-to-failure) – The duration of time between the first breaching of the upstream face of the dam (breach initiation) and when the breach has reached its full geometry.
* Breach depth (also breach height) – The breach depth is the vertical extent of the breach measured from a specific elevation to the invert of the dam breach.
* Breach width – The breach width is the average of the final breach width, typically measured at the vertical center of the breach.
* Breach side slope factor – the breach side slope is a measure of the angle of the breach sides represented as X horizontal to 1 vertical (XH: 1V).

“A dam breach usually occurs in two distinct phases starting with the breach initiation followed by the breach formation.

“Breach initiation: During the breach initiation phase, flow through the dam is minor and the dam is not considered to have failed. It may be possible to prevent a dam breach during this phase if flow is controlled.

“Breach formation: Breach formation (defined above) begins when the flow through the dam has increased and progressed from the upstream face to the downstream face of the dam, is uncontrolled, and will result in the failure of the dam” <ref name ="FEMA P-946">[[Federal Guidelines for Inundation Mapping of Flood Risks Associated with Dam Incidents and Failures (FEMA P-946) | FEMA P-946 Federal Guidelines for Inundation Mapping of Flood Risks Associated with Dam Incidents and Failures, FEMA, 2013]]</ref>.

==Published Breach Parameter Estimation Methods==

“Physically Based Erosion Methods – These methods predict the development of an embankment breach and the resulting breach outflows using an erosion model based on principles of hydraulics, sediment transport, and soil mechanics.

“Parametric Regression Equations – These equations, developed from case study information, are used to estimate the time-to-failure and ultimate breach geometry. The breach can then be simulated to proceed as a time-dependent linear process with the computation breach outflows using principles of hydraulics.

“Predictor Regression Equations – These equations estimate the dam breach peak discharge empirically based on case study data of peak discharge and hydrograph shape” <ref name ="FEMA P-946">[[Federal Guidelines for Inundation Mapping of Flood Risks Associated with Dam Incidents and Failures (FEMA P-946) | FEMA P-946 Federal Guidelines for Inundation Mapping of Flood Risks Associated with Dam Incidents and Failures, FEMA, 2013]]</ref>.

==Other Relevant Quotes==

“The breach is the opening formed in the dam when it fails. Despite the fact that the main modes of failure have been identified as piping or overtopping, the actual failure mechanics are not well understood for either earthen or concrete dams. In previous attempts to predict downstream flooding due to dam failures, it was usually assumed that the dam failed completely and instantaneously. These assumptions of instantaneous and complete breaches were used for reasons of convenience when applying certain mathematical techniques for analyzing dam-break flood waves. The presumptions are somewhat appropriate for concrete arch-type dams, but they are not suitable for earthen dams and concrete gravity-type dams” <ref name ="EM 1110-2-1420">[[Hydrologic Engineering Requirements for Reservoirs (EM 1110-2-1420) | EM 1110-2-1420 Hydrologic Engineering Requirements for Reservoirs, USACE, 1997]]</ref>.

==Examples==
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Reservoir Data

2022-09-11T15:30:34Z

Pcampana: Created page with "__NOTOC__ ----  [Page Summary] “Typically, several hydrologic and non-hydrologic (fair weather) events are evaluated as part of an event-based dam safety analysis. For hydrologic failure events, an extreme flood event ranging from the 50-year event for low-hazard dams up to the PMF for high-hazard dams is selected based on the potential for loss of life due to a dam failu..."

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[Page Summary]

“Typically, several hydrologic and non-hydrologic (fair weather) events are evaluated as part of an event-based dam safety analysis. For hydrologic failure events, an extreme flood event ranging from the 50-year event for low-hazard dams up to the PMF for high-hazard dams is selected based on the potential for loss of life due to a dam failure or for significant economic and environmental losses. Typically the hazard potential classification of the dam is used to selected the extreme hydrologic failure event. The PMF is the flood that may be expected from the most severe combination of critical meteorological and hydrologic conditions that are reasonably possible in the drainage basin under study. The Probable Maximum Precipitation (PMP) is an estimate of the maximum possible precipitation depth over a given size catchment for a given length of time (Stedinger et al., 1996).

“A fair weather (Sunny Day) breach is a dam failure that occurs during fair weather (i.e. non-hydrologic or non-precipitation) conditions. A fair weather breach is analyzed by establishing an initial reservoir water level and commencing a breach analysis without additional inflow from a storm event. A fair weather breach is typically used to model piping failures for hydrologic, geologic, structural, seismic, and human-influenced failure modes.

“Base flow conditions for a fair weather failure are typically ignored because of the small discharge and volume compared to that of a dam breach. As a general guidance, base flow can be ignored if the dam breach flow is two times greater than the base flow. Where base flow is considered, the discharge is typically estimated based on reported base flows through the dam’s outlet works or from stream gage records. The three most common initial water level elevations for fair weather breach analyses are as follows:
* “Normal Pool Elevation (invert of the highest elevation of the primary outlet): A breach at the normal pool elevation of the reservoir is used to estimate the volume and associated breach discharge that would result from a failure event during fair weather conditions. For an embankment dam, this type of event is modeled as piping/internal erosion failure, whereas for a concrete dam, this event is modeled as a monolith collapse resulting from sliding, foundation instabilities, or a seismic event.

* “Invert of Auxiliary Spillway (lowest uncontrolled spillway): A breach of the dam with the reservoir water level set at the auxiliary spillway (also referred to as an emergency spillway) is common practice to simulate a breach during misoperation of the primary outlet works. Initiation of dam failure is typically the same as for the reservoir level at normal pool.

* “Top of Dam / Maximum High Pool: The reservoir level set to the top of the dam to represent the maximum amount of volume that may be stored in the reservoir. This condition may be selected to evaluate the most conservative non-hydrologic event. In practice, dams without adequate spillways or pump storage facilities, where the water level during non-hydrologic events is maintained at the top of the dam, are unique situations subject to this conservative assumption. A breach event when the water level is at the top of the dam may be modeled as a piping/internal erosion failure or as an overtopping failure with the water level just above the top of dam invert.

“Various Federal agency publications provide guidance for establishing the initial water surface elevation of a reservoir during a fair weather failure event. Each of these specified elevations is used to characterize different failure modes as well as the potential volume of the reservoir at the time of failure” <ref name ="FEMA P-946">[[Federal Guidelines for Inundation Mapping of Flood Risks Associated with Dam Incidents and Failures (FEMA P-946) | FEMA P-946 Federal Guidelines for Inundation Mapping of Flood Risks Associated with Dam Incidents and Failures, FEMA, 2013]]</ref>.

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Terrain Data

2022-09-11T15:20:35Z

Pcampana: Created page with "__NOTOC__ ----  [Page Summary] “The USDOI in its report Inundation Mapping/Modeling Subproject Report, Implementation Phase 1: Launch Risk Reduction, dated March 2011, recommends that as a general rule, larger dam breach flows, in terms of peak breach discharge and volume, do not require as detailed terrain data as would smaller flows. Smaller flood flow requires a more d..."

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[Page Summary]

“The USDOI in its report Inundation Mapping/Modeling Subproject Report, Implementation Phase 1: Launch Risk Reduction, dated March 2011, recommends that as a general rule, larger dam breach flows, in terms of peak breach discharge and volume, do not require as detailed terrain data as would smaller flows. Smaller flood flow requires a more detailed definition of drainage paths, which creates a need for more accurate terrain data.

“Before performing an inundation study, available terrain sources should be carefully evaluated to identify the best-available data by considering numerous factors, including date, accuracy, and spatial extent of data to name a few. For instance, the selection of the level of detail and accuracy of the terrain data to be used for a dam breach study should consider the level of detail of the hydrologic and hydraulic modeling used for the study. A tier 1 simple and basic study, described in section 6.3 of this guidance document, covering a rural area does not warrant the same level of detailed terrain data as tier 2 intermediate or tier 3 advanced studies for heavily populated areas. Section 9 provides further discussion on terrain data and cross-section accuracy for use in dam breach studies.

“To achieve a suitable level of accuracy, it may be necessary to combine multiple terrain datasets to ensure that either the best available or an acceptable accuracy terrain data source is utilized throughout the spatial extent of the inundation. When combining terrain datasets, edge matching must be carefully reviewed to ensure that no artificial walls or drops are inadvertently created during the merge. Combined datasets must also use consistent horizontal and vertical datum and units” <ref name ="FEMA P-946">[[Federal Guidelines for Inundation Mapping of Flood Risks Associated with Dam Incidents and Failures (FEMA P-946) | FEMA P-946 Federal Guidelines for Inundation Mapping of Flood Risks Associated with Dam Incidents and Failures, FEMA, 2013]]</ref>.

==Examples==
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==Best Practices Resources==
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==Trainings==
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Dam Breach Inundation Analysis

2022-09-09T23:11:00Z

Pcampana:

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[Page Summary]

“Safety design includes studies to ascertain areas that would be flooded during occurrence of the design flood and in the event of dam failure. The areas downstream from the project should be evaluated to determine the needs for land acquisition, flood plain management, or other methods to prevent major damage. Information should be developed and documented suitable for releasing to downstream interests regarding remaining risks of flooding.” <ref name ="FEMA93">[[Federal Guidelines for Dam Safety (FEMA P-93) | FEMA 93 Federal Guidelines for Dam Safety, FEMA, 2004 ]]</ref>

“The selection of an appropriate model for computing a dam breach is dependent on the type of results needed, the level of effort that can be expended, and the potential for loss of life and economic damages that can result from a dam failure"

“For dams in rural areas where the potential for loss of life is low, a tier 1 level study using simplified methods may be appropriate. For areas where a potential dam breach can result in the loss of life an intermediate tier 2 level or advanced tier 3 should be performed. The intermediate tier 2 level study may be used for areas where more detailed calculations are justified because of the potential for loss of life. Advanced tier 3 level studies may be needed to develop dam breach inundation zone mapping for urbanized areas and for unconfined floodplains.” <ref name ="FEMA946">[[Federal Guidelines for Inundation Mapping of Flood Risks Associated with Dam Incidents and Failures (FEMA P-946) | FEMA P-946 Federal Guidelines for Inundation Mapping of Flood Risks Associated with Dam Incidents and Dam Failures, FEMA, 2013 ]]</ref>

==Required Data==
*[[Terrain Data]]

*[[Reservoir Data]]

*[[Breach Parameters]]

*[[Land Roughness]]

==Types of Analyses==
*[[Hazard Potential Classification]]

*[[Consequence Analysis]]

*[[Incremental Damaga Analysis]]

*[[Inundation Mapping]]

*[[Emergency Action Planning]]

Info

==Examples==
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==Best Practices Resources==
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==Trainings==
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Hydraulic Performance of Outlet Works

2022-09-09T23:02:42Z

Pcampana: Created page with "__NOTOC__ ----  Page Summary ==Outlet Works Hydraulics== “The hydraulic analysis of the flow through a flood control conduit or sluice usually involves consideration of two conditions of low. When the upper pool is at low stages, for example during diversion, open-channel flow may occur in the conduit. As the reservoir level is raised, the depth of flow in the conduit inc..."

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Page Summary

==Outlet Works Hydraulics==
“The hydraulic analysis of the flow through a flood control conduit or sluice usually involves consideration of two conditions of low. When the upper pool is at low stages, for example during diversion, open-channel flow may occur in the conduit. As the reservoir level is raised, the depth of flow in the conduit increases until the conduit flows full. In the design of outlet works, the number and size of the conduits and the elevations of their grade line are determined with consideration of overall costs. The conduits are usually designed to provide the required discharge capacity at a specified reservoir operating level, although adequate capacity during diversion may govern in some cases. Conduits should normally slope downstream to ensure drainage. The elevation of good foundation materials may govern the invert elevation of conduits for an embankment dam.” <ref name ="EM1110-2-1602">[[Hydraulic Design of Reservoir Outlet Works (EM 1110-2-1602) | EM 1110-2-1602 Hydraulic Design of Reservoir Outlet Works, USACE, 1980]]</ref>

==Reservoir Drawdown==
“Where practicable, reservoir release facilities should be provided to lower the pool to a safe level adequate to correct conditions that might threaten the integrity f the dam.” <ref name ="FEMA93">[[Federal Guidelines for Dam Safety (FEMA P-93) | FEMA 93 Federal Guidelines for Dam Safety, FEMA, 2004 ]]</ref>

“Low level outlets are provided to maintain downstream flows for all levels of the reservoirs operational pool. The outlets may also serve to empty the reservoir to permit inspection, to make needed repairs, or to maintain the upstream face of the dam or other structures normally inundated.” <ref name ="EM-1110-2-1420">[[Hydrologic Engineering Requirements for Reservoirs (EM 1110-2-1420)| EM 1110-2-1420 Hydrologic Engineering Requirements for Reservoirs, USACE, 1997 ]]</ref>

Info

==Examples==
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==Best Practices Resources==
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==Trainings==
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Dam Breach Inundation Analysis

2022-09-09T22:50:42Z

Pcampana: Created page with "__NOTOC__ ----  [Page Summary] “Safety design includes studies to ascertain areas that would be flooded during occurrence of the design flood and in the event of dam failure. The areas downstream from the project should be evaluated to determine the needs for land acquisition, flood plain management, or other methods to prevent major damage. Information should be develope..."

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[Page Summary]

“Safety design includes studies to ascertain areas that would be flooded during occurrence of the design flood and in the event of dam failure. The areas downstream from the project should be evaluated to determine the needs for land acquisition, flood plain management, or other methods to prevent major damage. Information should be developed and documented suitable for releasing to downstream interests regarding remaining risks of flooding” (FEMA 93 Federal Guidelines for Dam Safety, FEMA, 2004).

“The selection of an appropriate model for computing a dam breach is dependent on the type of results needed, the level of effort that can be expended, and the potential for loss of life and economic damages that can result from a dam failure.

“For dams in rural areas where the potential for loss of life is low, a tier 1 level study using simplified methods may be appropriate. For areas where a potential dam breach can result in the loss of life an intermediate tier 2 level or advanced tier 3 should be performed. The intermediate tier 2 level study may be used for areas where more detailed calculations are justified because of the potential for loss of life. Advanced tier 3 level studies may be needed to develop dam breach inundation zone mapping for urbanized areas and for unconfined floodplains” (FEMA P-946 Federal Guidelines for Inundation Mapping of Flood Risks Associated with Dam Incidents and Dam Failures, FEMA, 2013).

==Required Data==
*[[Terrain Data]]

*[[Reservoir Data]]

*[[Breach Parameters]]

*[[Land Roughness]]

==Types of Analyses==
*[[Hazard Potential Classification]]

*[[Consequence Analysis]]

*[[Incremental Damaga Analysis]]

*[[Inundation Mapping]]

*[[Emergency Action Planning]]

Info

==Examples==
{{Website Icon}}
==Best Practices Resources==
{{Document Icon}}
==Trainings==
{{Video Icon}}


{{Citations}}


{{revhistinf}}

Hydraulic Performance of Spillways

2022-09-09T22:33:22Z

Pcampana:

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[Page Summary]

==Reservoir Routing==
“This procedure derives the outflow hydrograph from a reservoir from the inflow hydrograph into the reservoir with consideration of elevation, storage, and discharge characteristics of the reservoir and spillways. The conservation of mass equation is solved with the assumption that outflow discharge and volume of storage are directly related.” <ref name="NEH_CH17">[[Part 630 Hydrology National Engineering Handbook: Chapter 17 Flood Routing | Part 630 Hydrology National Engineering Handbook: Chapter 17 Flood Routing, NRCS, 2014]]</ref>
“For reservoirs, the relation of surface area and release capacity to storage content must be described. Characteristics of the control gates on the outlets and spillway must be known in order to determine constraints on operation. The top-of-dam elevation must be specified and the ability of the structure to withstand overtopping must be assessed.” <ref name ="EM1110-2-1420">[[Hydrologic Engineering Requirements for Reservoirs (EM 1110-2-1420) | EM 1110-2-1420 Hydrologic Engineering Requirements for Reservoirs, USACE, 1997 ]]</ref>.

==Spillway Approach Hydraulics==
“Spillway approach configuration will influence the abutment contraction coefficient, the nappe profile, and possibly the flow characteristics throughout the spillway chute and stilling basin.” <ref name="EM110-2-1603">[[Hydraulic Design of Spillways (EM 1110-2-1603) | EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992]]</ref>

“Crest piers, abutments, and approach configurations of a variety of shapes and sizes have been used in conjunction with spillways... Not all of the designs have produced the intended results. Improper designs have led to cavitation damage, drastic reduction in the discharge capacity, unacceptable waves in the spillway chute, and harmonic surges in the spillway bays upstream from the gates. Maintaining the high efficiency of a spillway requires careful design of the spillway crest, the approach configuration, and the piers and abutments. For this reason, when design considerations require departure from established design data, model studies of the spillway system should be accomplished.” <ref name="EM110-2-1603">[[Hydraulic Design of Spillways (EM 1110-2-1603) | EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992]]</ref>

“Another factor influencing the discharge coefficient of a spillway crest is the depth in the approach channel relative to the design head... As the depth of the approach channel … decreases relative to the design head, the effect of approach velocity becomes more significant. The slope of the upstream spillway face also influences the coefficient of discharge… the flatter upstream face slopes tend to produce an increase in the discharge coefficient. <ref name="EM110-2-1603">[[Hydraulic Design of Spillways (EM 1110-2-1603) | EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992]]</ref>

==Spillway Control Structures==
“The value of an uncontrolled fixed crest spillway in providing an extremely reliable operation and a very low-cost maintenance facility is undeniable. Topographical, geological, economical, and political considerations at many dam sites may restrict the use of an uncontrolled fixed crest spillway. The solution to these problems is usually the inclusion of crest gates; however, the uncontrolled fixed crest spillway should be used regardless of these considerations when the time of concentration of the basin runoff into the reservoir is less than 12 hours. When the time of concentration is between 12 and 24 hours, an uncontrolled fixed crest spillway should be given preference over a gated spillway. Basically, the inclusion of crest gates allows the spillway crest to be placed significantly below the maximum operating reservoir level, in turn, permitting the entire reservoir to be used for normal operating purposes; and results in a much narrower spillway facility, avoiding the problems associated with high unit discharge/high-velocity flow and increased operation and maintenance costs. A gated spillway must include, as a minimum, two or preferably three spillway gates in order to satisfy safety concerns” <ref name="EM110-2-1603">[[Hydraulic Design of Spillways (EM 1110-2-1603) | EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992]]</ref>

==Spillway Chute Hydraulics==
“The chute is that portion of the spillway which connects the crest curve to the terminal structure. The term chute when used in conjunction with a spillway implies that the velocity is supercritical; thus, the Froude number is greater than one. When the spillway is an integral part of a concrete gravity monolith, the chute is usually very steep. Chutes as steep as 1.0 vertical on 0.7 horizontal are not uncommon. The steepness thus minimizes the chute length. Chutes used in conjunction with embankment dams often must be long with a slop slightly steeper than the critical slope. This long, prominent structure is termed a chute spillway. The designs for long spillway chutes and steep chutes on concrete dam monoliths involve many of the same geometric and hydraulic considerations. Due to the extreme slope and short length of a steep chute, many of the hydraulic characteristics that become prominent in spillway chutes have insufficient time to develop prior to reaching the terminal structure.” <ref name="EM110-2-1603">[[Hydraulic Design of Spillways (EM 1110-2-1603) | EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992]]</ref>

“Hydraulic characteristics that must be considered in the design of a chute are the velocity and depth of flow, air entrainment of the flow, pier and abutment waves, floor and wall pressures, cavitation indices, superelevation of the flow surface at curves, and standing waves due to the geometry of the chute. Obtaining acceptable hydraulic characteristics is dependent upon developing proper geometric conditions that include chute floor slope changes, horizontal alignment changes (curves), and sidewall convergence… A model study is recommended to confirm any design that involves complex geometric considerations and/or large discharges and velocities.” <ref name="EM110-2-1603">[[Hydraulic Design of Spillways (EM 1110-2-1603) | EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992]]</ref>

Spillway chutes do not have to be designed with parallel sidewalls. Chutes commonly are designed and constructed with either diverging or converging sidewalls for a variety of site-specific reasons. “The height of a chute sidewall should be designed to contain the flow of the spillway design flood… The computed profile may require adjustment to account for the effects of pier end waves, slug flow or roll waves, and air entrainment. Sidewall freeboard is added above the adjusted profile; as a minimum, two feet of freeboard is recommended.” <ref name="EM110-2-1603">[[Hydraulic Design of Spillways (EM 1110-2-1603) | EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992]]</ref>

==Spillway Terminal Structure Hydraulics==
“The design of the energy dissipator probably includes more options than any other phase of spillway design. The selection of the type and design details of the dissipator is largely dependent upon the pertinent characteristics of the site, the magnitude of energy to be dissipated, and to a lesser extent upon the duration and frequency of spillway use. Good judgement is imperative to assure that all requirements of the particular project are met. Regardless of the type of dissipator selected, any spillway energy dissipator must operate safety at high discharges for extended periods of time without having to be shut down for emergency repairs. An emergency shutdown of the spillway facility during a large flood could cause overtopping of the dam and/or create unacceptable upstream flooding.” <ref name="EM110-2-1603">[[Hydraulic Design of Spillways (EM 1110-2-1603) | EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992]]</ref>

“Except in some unusual conditions, an exit channel is required to transition between the stilling basin and the main channel of the river. Since dissipation of the entire spillway discharge energy within the stilling basin is not normally accomplished, enlarging the channel width immediately downstream from the (stilling) basin will assist in dissipating the residual energy. Due to the erosive nature of the highly turbulent flow exiting from a stilling basin, protection of the exit channel bed and side slopes is usually required to prevent channel scout and potential undermining of the stilling basin.” <ref name="EM110-2-1603">[[Hydraulic Design of Spillways (EM 1110-2-1603) | EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992]]</ref>

Info

==Examples==
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==Best Practices Resources==
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Part 630 Hydrology National Engineering Handbook: Chapter 17 Flood Routing

2022-09-09T22:19:33Z

Pcampana: Created page with "{{References Template |author=  Natural Resources Conservation Service |date=  2014 |picture=  File:NEH17.jpg |link=  https://directives.sc.egov.usda.gov/OpenNonWebContent.aspx?content=35555.wba..."

{{References Template

|author=

Natural Resources Conservation Service

|date=

2014

|picture=

File:NEH17.jpg

|link=

https://directives.sc.egov.usda.gov/OpenNonWebContent.aspx?content=35555.wba

|abstract=

Chapter 17 (NEH630.17) presents a systematic approach to and various examples of flood routing and flood routing calculations. S

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Hydraulic Performance of Spillways

2022-09-09T22:07:41Z

Pcampana:

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[Page Summary]

==Reservoir Routing==
“This procedure derives the outflow hydrograph from a reservoir from the inflow hydrograph into the reservoir with consideration of elevation, storage, and discharge characteristics of the reservoir and spillways. The conservation of mass equation is solved with the assumption that outflow discharge and volume of storage are directly related.” <ref name="NEH_CH17">[[Part 630 Hydrology National Engineering Handbook: Chapter 17 Flood Routing | Part 630 Hydrology National Engineering Handbook: Chapter 17 Flood Routing, NRCS, 2014]]</ref>
“For reservoirs, the relation of surface area and release capacity to storage content must be described. Characteristics of the control gates on the outlets and spillway must be known in order to determine constraints on operation. The top-of-dam elevation must be specified and the ability of the structure to withstand overtopping must be assessed” (EM 1110-2-1420 Hydrologic Engineering Requirements for Reservoirs, USACE, 1997).

==Spillway Approach Hydraulics==
“Spillway approach configuration will influence the abutment contraction coefficient, the nappe profile, and possibly the flow characteristics throughout the spillway chute and stilling basin” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

“Crest piers, abutments, and approach configurations of a variety of shapes and sizes have been used in conjunction with spillways... Not all of the designs have produced the intended results. Improper designs have led to cavitation damage, drastic reduction in the discharge capacity, unacceptable waves in the spillway chute, and harmonic surges in the spillway bays upstream from the gates. Maintaining the high efficiency of a spillway requires careful design of the spillway crest, the approach configuration, and the piers and abutments. For this reason, when design considerations require departure from established design data, model studies of the spillway system should be accomplished” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

“Another factor influencing the discharge coefficient of a spillway crest is the depth in the approach channel relative to the design head... As the depth of the approach channel … decreases relative to the design head, the effect of approach velocity becomes more significant. The slope of the upstream spillway face also influences the coefficient of discharge… the flatter upstream face slopes tend to produce an increase in the discharge coefficient (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

==Spillway Control Structures==
“The value of an uncontrolled fixed crest spillway in providing an extremely reliable operation and a very low-cost maintenance facility is undeniable. Topographical, geological, economical, and political considerations at many dam sites may restrict the use of an uncontrolled fixed crest spillway. The solution to these problems is usually the inclusion of crest gates; however, the uncontrolled fixed crest spillway should be used regardless of these considerations when the time of concentration of the basin runoff into the reservoir is less than 12 hours. When the time of concentration is between 12 and 24 hours, an uncontrolled fixed crest spillway should be given preference over a gated spillway. Basically, the inclusion of crest gates allows the spillway crest to be placed significantly below the maximum operating reservoir level, in turn, permitting the entire reservoir to be used for normal operating purposes; and results in a much narrower spillway facility, avoiding the problems associated with high unit discharge/high-velocity flow and increased operation and maintenance costs. A gated spillway must include, as a minimum, two or preferably three spillway gates in order to satisfy safety concerns” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

==Spillway Chute Hydraulics==
“The chute is that portion of the spillway which connects the crest curve to the terminal structure. The term chute when used in conjunction with a spillway implies that the velocity is supercritical; thus, the Froude number is greater than one. When the spillway is an integral part of a concrete gravity monolith, the chute is usually very steep. Chutes as steep as 1.0 vertical on 0.7 horizontal are not uncommon. The steepness thus minimizes the chute length. Chutes used in conjunction with embankment dams often must be long with a slop slightly steeper than the critical slope. This long, prominent structure is termed a chute spillway. The designs for long spillway chutes and steep chutes on concrete dam monoliths involve many of the same geometric and hydraulic considerations. Due to the extreme slope and short length of a steep chute, many of the hydraulic characteristics that become prominent in spillway chutes have insufficient time to develop prior to reaching the terminal structure” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

“Hydraulic characteristics that must be considered in the design of a chute are the velocity and depth of flow, air entrainment of the flow, pier and abutment waves, floor and wall pressures, cavitation indices, superelevation of the flow surface at curves, and standing waves due to the geometry of the chute. Obtaining acceptable hydraulic characteristics is dependent upon developing proper geometric conditions that include chute floor slope changes, horizontal alignment changes (curves), and sidewall convergence… A model study is recommended to confirm any design that involves complex geometric considerations and/or large discharges and velocities” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

Spillway chutes do not have to be designed with parallel sidewalls. Chutes commonly are designed and constructed with either diverging or converging sidewalls for a variety of site-specific reasons. “The height of a chute sidewall should be designed to contain the flow of the spillway design flood… The computed profile may require adjustment to account for the effects of pier end waves, slug flow or roll waves, and air entrainment. Sidewall freeboard is added above the adjusted profile; as a minimum, two feet of freeboard is recommended” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

==Spillway Terminal Structure Hydraulics==
“The design of the energy dissipator probably includes more options than any other phase of spillway design. The selection of the type and design details of the dissipator is largely dependent upon the pertinent characteristics of the site, the magnitude of energy to be dissipated, and to a lesser extent upon the duration and frequency of spillway use. Good judgement is imperative to assure that all requirements of the particular project are met. Regardless of the type of dissipator selected, any spillway energy dissipator must operate safety at high discharges for extended periods of time without having to be shut down for emergency repairs. An emergency shutdown of the spillway facility during a large flood could cause overtopping of the dam and/or create unacceptable upstream flooding” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

“Except in some unusual conditions, an exit channel is required to transition between the stilling basin and the main channel of the river. Since dissipation of the entire spillway discharge energy within the stilling basin is not normally accomplished, enlarging the channel width immediately downstream from the (stilling) basin will assist in dissipating the residual energy. Due to the erosive nature of the highly turbulent flow exiting from a stilling basin, protection of the exit channel bed and side slopes is usually required to prevent channel scout and potential undermining of the stilling basin” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

Info

==Examples==
{{Website Icon}}
==Best Practices Resources==
{{Document Icon}}
==Trainings==
{{Video Icon}}


{{Citations}}


{{revhistinf}}

File:HNEH Ch17 FldRoute.JPG

2022-09-09T22:04:51Z

Pcampana: Title Page of Ch 17 of NRCS National Engineering Handbook

== Summary ==
Title Page of Ch 17 of NRCS National Engineering Handbook

Hydraulic Performance of Spillways

2022-09-09T22:01:35Z

Pcampana:

__NOTOC__
----

[Page Summary]

==Reservoir Routing==
“This procedure derives the outflow hydrograph from a reservoir from the inflow hydrograph into the reservoir with consideration of elevation, storage, and discharge characteristics of the reservoir and spillways. The conservation of mass equation is solved with the assumption that outflow discharge and volume of storage are directly related.” <ref name="NEH_CH17">[[Part 630 Hydrology National Engineering Handbook: Chapter 17 Flood Routing | Part 630 Hydrology National Engineering Handbook: Chapter 17 Flood Routing, , NRCS, 2014]]</ref>
“For reservoirs, the relation of surface area and release capacity to storage content must be described. Characteristics of the control gates on the outlets and spillway must be known in order to determine constraints on operation. The top-of-dam elevation must be specified and the ability of the structure to withstand overtopping must be assessed” (EM 1110-2-1420 Hydrologic Engineering Requirements for Reservoirs, USACE, 1997).

==Spillway Approach Hydraulics==
“Spillway approach configuration will influence the abutment contraction coefficient, the nappe profile, and possibly the flow characteristics throughout the spillway chute and stilling basin” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

“Crest piers, abutments, and approach configurations of a variety of shapes and sizes have been used in conjunction with spillways... Not all of the designs have produced the intended results. Improper designs have led to cavitation damage, drastic reduction in the discharge capacity, unacceptable waves in the spillway chute, and harmonic surges in the spillway bays upstream from the gates. Maintaining the high efficiency of a spillway requires careful design of the spillway crest, the approach configuration, and the piers and abutments. For this reason, when design considerations require departure from established design data, model studies of the spillway system should be accomplished” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

“Another factor influencing the discharge coefficient of a spillway crest is the depth in the approach channel relative to the design head... As the depth of the approach channel … decreases relative to the design head, the effect of approach velocity becomes more significant. The slope of the upstream spillway face also influences the coefficient of discharge… the flatter upstream face slopes tend to produce an increase in the discharge coefficient (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

==Spillway Control Structures==
“The value of an uncontrolled fixed crest spillway in providing an extremely reliable operation and a very low-cost maintenance facility is undeniable. Topographical, geological, economical, and political considerations at many dam sites may restrict the use of an uncontrolled fixed crest spillway. The solution to these problems is usually the inclusion of crest gates; however, the uncontrolled fixed crest spillway should be used regardless of these considerations when the time of concentration of the basin runoff into the reservoir is less than 12 hours. When the time of concentration is between 12 and 24 hours, an uncontrolled fixed crest spillway should be given preference over a gated spillway. Basically, the inclusion of crest gates allows the spillway crest to be placed significantly below the maximum operating reservoir level, in turn, permitting the entire reservoir to be used for normal operating purposes; and results in a much narrower spillway facility, avoiding the problems associated with high unit discharge/high-velocity flow and increased operation and maintenance costs. A gated spillway must include, as a minimum, two or preferably three spillway gates in order to satisfy safety concerns” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

==Spillway Chute Hydraulics==
“The chute is that portion of the spillway which connects the crest curve to the terminal structure. The term chute when used in conjunction with a spillway implies that the velocity is supercritical; thus, the Froude number is greater than one. When the spillway is an integral part of a concrete gravity monolith, the chute is usually very steep. Chutes as steep as 1.0 vertical on 0.7 horizontal are not uncommon. The steepness thus minimizes the chute length. Chutes used in conjunction with embankment dams often must be long with a slop slightly steeper than the critical slope. This long, prominent structure is termed a chute spillway. The designs for long spillway chutes and steep chutes on concrete dam monoliths involve many of the same geometric and hydraulic considerations. Due to the extreme slope and short length of a steep chute, many of the hydraulic characteristics that become prominent in spillway chutes have insufficient time to develop prior to reaching the terminal structure” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

“Hydraulic characteristics that must be considered in the design of a chute are the velocity and depth of flow, air entrainment of the flow, pier and abutment waves, floor and wall pressures, cavitation indices, superelevation of the flow surface at curves, and standing waves due to the geometry of the chute. Obtaining acceptable hydraulic characteristics is dependent upon developing proper geometric conditions that include chute floor slope changes, horizontal alignment changes (curves), and sidewall convergence… A model study is recommended to confirm any design that involves complex geometric considerations and/or large discharges and velocities” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

Spillway chutes do not have to be designed with parallel sidewalls. Chutes commonly are designed and constructed with either diverging or converging sidewalls for a variety of site-specific reasons. “The height of a chute sidewall should be designed to contain the flow of the spillway design flood… The computed profile may require adjustment to account for the effects of pier end waves, slug flow or roll waves, and air entrainment. Sidewall freeboard is added above the adjusted profile; as a minimum, two feet of freeboard is recommended” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

==Spillway Terminal Structure Hydraulics==
“The design of the energy dissipator probably includes more options than any other phase of spillway design. The selection of the type and design details of the dissipator is largely dependent upon the pertinent characteristics of the site, the magnitude of energy to be dissipated, and to a lesser extent upon the duration and frequency of spillway use. Good judgement is imperative to assure that all requirements of the particular project are met. Regardless of the type of dissipator selected, any spillway energy dissipator must operate safety at high discharges for extended periods of time without having to be shut down for emergency repairs. An emergency shutdown of the spillway facility during a large flood could cause overtopping of the dam and/or create unacceptable upstream flooding” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

“Except in some unusual conditions, an exit channel is required to transition between the stilling basin and the main channel of the river. Since dissipation of the entire spillway discharge energy within the stilling basin is not normally accomplished, enlarging the channel width immediately downstream from the (stilling) basin will assist in dissipating the residual energy. Due to the erosive nature of the highly turbulent flow exiting from a stilling basin, protection of the exit channel bed and side slopes is usually required to prevent channel scout and potential undermining of the stilling basin” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

Info

==Examples==
{{Website Icon}}
==Best Practices Resources==
{{Document Icon}}
==Trainings==
{{Video Icon}}


{{Citations}}


{{revhistinf}}

Hydraulic Performance of Spillways

2022-09-09T22:00:21Z

Pcampana: Created page with "__NOTOC__ ----  [Page Summary] ==Reservoir Routing== “This procedure derives the outflow hydrograph from a reservoir from the inflow hydrograph into the reservoir with consideration of elevation, storage, and discharge characteristics of the reservoir and spillways. The conservation of mass equation is solved with the assumption that outflow discharge and volume of storag..."

__NOTOC__
----

[Page Summary]

==Reservoir Routing==
“This procedure derives the outflow hydrograph from a reservoir from the inflow hydrograph into the reservoir with consideration of elevation, storage, and discharge characteristics of the reservoir and spillways. The conservation of mass equation is solved with the assumption that outflow discharge and volume of storage are directly related.” <ref name="NEH_CH17">[[Part 630 Hydrology National Engineering Handbook: Chapter 17 Flood Routing, NRCS, 2014 | Part 630 Hydrology National Engineering Handbook: Chapter 17 Flood Routing]]</ref> (Part 630 Hydrology National Engineering Handbook: Chapter 17 Flood Routing, NRCS, 2014).

“For reservoirs, the relation of surface area and release capacity to storage content must be described. Characteristics of the control gates on the outlets and spillway must be known in order to determine constraints on operation. The top-of-dam elevation must be specified and the ability of the structure to withstand overtopping must be assessed” (EM 1110-2-1420 Hydrologic Engineering Requirements for Reservoirs, USACE, 1997).

==Spillway Approach Hydraulics==
“Spillway approach configuration will influence the abutment contraction coefficient, the nappe profile, and possibly the flow characteristics throughout the spillway chute and stilling basin” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

“Crest piers, abutments, and approach configurations of a variety of shapes and sizes have been used in conjunction with spillways... Not all of the designs have produced the intended results. Improper designs have led to cavitation damage, drastic reduction in the discharge capacity, unacceptable waves in the spillway chute, and harmonic surges in the spillway bays upstream from the gates. Maintaining the high efficiency of a spillway requires careful design of the spillway crest, the approach configuration, and the piers and abutments. For this reason, when design considerations require departure from established design data, model studies of the spillway system should be accomplished” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

“Another factor influencing the discharge coefficient of a spillway crest is the depth in the approach channel relative to the design head... As the depth of the approach channel … decreases relative to the design head, the effect of approach velocity becomes more significant. The slope of the upstream spillway face also influences the coefficient of discharge… the flatter upstream face slopes tend to produce an increase in the discharge coefficient (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

==Spillway Control Structures==
“The value of an uncontrolled fixed crest spillway in providing an extremely reliable operation and a very low-cost maintenance facility is undeniable. Topographical, geological, economical, and political considerations at many dam sites may restrict the use of an uncontrolled fixed crest spillway. The solution to these problems is usually the inclusion of crest gates; however, the uncontrolled fixed crest spillway should be used regardless of these considerations when the time of concentration of the basin runoff into the reservoir is less than 12 hours. When the time of concentration is between 12 and 24 hours, an uncontrolled fixed crest spillway should be given preference over a gated spillway. Basically, the inclusion of crest gates allows the spillway crest to be placed significantly below the maximum operating reservoir level, in turn, permitting the entire reservoir to be used for normal operating purposes; and results in a much narrower spillway facility, avoiding the problems associated with high unit discharge/high-velocity flow and increased operation and maintenance costs. A gated spillway must include, as a minimum, two or preferably three spillway gates in order to satisfy safety concerns” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

==Spillway Chute Hydraulics==
“The chute is that portion of the spillway which connects the crest curve to the terminal structure. The term chute when used in conjunction with a spillway implies that the velocity is supercritical; thus, the Froude number is greater than one. When the spillway is an integral part of a concrete gravity monolith, the chute is usually very steep. Chutes as steep as 1.0 vertical on 0.7 horizontal are not uncommon. The steepness thus minimizes the chute length. Chutes used in conjunction with embankment dams often must be long with a slop slightly steeper than the critical slope. This long, prominent structure is termed a chute spillway. The designs for long spillway chutes and steep chutes on concrete dam monoliths involve many of the same geometric and hydraulic considerations. Due to the extreme slope and short length of a steep chute, many of the hydraulic characteristics that become prominent in spillway chutes have insufficient time to develop prior to reaching the terminal structure” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

“Hydraulic characteristics that must be considered in the design of a chute are the velocity and depth of flow, air entrainment of the flow, pier and abutment waves, floor and wall pressures, cavitation indices, superelevation of the flow surface at curves, and standing waves due to the geometry of the chute. Obtaining acceptable hydraulic characteristics is dependent upon developing proper geometric conditions that include chute floor slope changes, horizontal alignment changes (curves), and sidewall convergence… A model study is recommended to confirm any design that involves complex geometric considerations and/or large discharges and velocities” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

Spillway chutes do not have to be designed with parallel sidewalls. Chutes commonly are designed and constructed with either diverging or converging sidewalls for a variety of site-specific reasons. “The height of a chute sidewall should be designed to contain the flow of the spillway design flood… The computed profile may require adjustment to account for the effects of pier end waves, slug flow or roll waves, and air entrainment. Sidewall freeboard is added above the adjusted profile; as a minimum, two feet of freeboard is recommended” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

==Spillway Terminal Structure Hydraulics==
“The design of the energy dissipator probably includes more options than any other phase of spillway design. The selection of the type and design details of the dissipator is largely dependent upon the pertinent characteristics of the site, the magnitude of energy to be dissipated, and to a lesser extent upon the duration and frequency of spillway use. Good judgement is imperative to assure that all requirements of the particular project are met. Regardless of the type of dissipator selected, any spillway energy dissipator must operate safety at high discharges for extended periods of time without having to be shut down for emergency repairs. An emergency shutdown of the spillway facility during a large flood could cause overtopping of the dam and/or create unacceptable upstream flooding” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

“Except in some unusual conditions, an exit channel is required to transition between the stilling basin and the main channel of the river. Since dissipation of the entire spillway discharge energy within the stilling basin is not normally accomplished, enlarging the channel width immediately downstream from the (stilling) basin will assist in dissipating the residual energy. Due to the erosive nature of the highly turbulent flow exiting from a stilling basin, protection of the exit channel bed and side slopes is usually required to prevent channel scout and potential undermining of the stilling basin” (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

Info

==Examples==
{{Website Icon}}
==Best Practices Resources==
{{Document Icon}}
==Trainings==
{{Video Icon}}


{{Citations}}


{{revhistinf}}

Hydraulics

2022-09-09T21:30:10Z

Pcampana:

__NOTOC__
----

The hydraulic design of a dam includes a knowledge of, but not limited to, the following foundational topics: pressurized and free-surface flow, uniform flow, gradually and rapidly varied flow, steady and unsteady flow, energy and momentum principles, energy losses, and cavitation. <ref name="HydDoS">[[Hydraulic Design of Spillways (EM 1110-2-1603) | Hydraulic Design of Spillways (EM 1110-2-1603)]]</ref>

==Hydraulic Design Criteria==
[paragraph here]

==Types of Evaluations==
[paragraph here]

*[[Hydraulic Performance of Spillways]]

*[[Hydraulic Performance of Outlet Works]]

*[[Dam Breach Inundation Analysis]]

*[[Scour Analysis]]

*[[Tailwater Modeling]]

==Types of Hydraulic Modeling==
*[[One-Dimensional Hydraulic Models]]

*[[Two-Dimensional Hydraulic Models]]

*[[Three-Dimensional Hydraulic Models]]

==Examples==
{{Website Icon}}
==Best Practices Resources==
{{Document Icon}}
==Trainings==
{{Video Icon}}


{{Citations}}


{{revhistinf}}

Hydraulics

2022-09-09T21:28:47Z

Pcampana:

__NOTOC__
----

The hydraulic design of a dam includes a knowledge of, but not limited to, the following foundational topics: pressurized and free-surface flow, uniform flow, gradually and rapidly varied flow, steady and unsteady flow, energy and momentum principles, energy losses, and cavitation. <ref name="HydDoS">[[Hydraulic Design of Spillways (EM 1110-2-1603) | Hydraulic Design of Spillways]]</ref>

==Hydraulic Design Criteria==
[paragraph here]

==Types of Evaluations==
[paragraph here]

*[[Hydraulic Performance of Spillways]]

*[[Hydraulic Performance of Outlet Works]]

*[[Dam Breach Inundation Analysis]]

*[[Scour Analysis]]

*[[Tailwater Modeling]]

==Types of Hydraulic Modeling==
*[[One-Dimensional Hydraulic Models]]

*[[Two-Dimensional Hydraulic Models]]

*[[Three-Dimensional Hydraulic Models]]

==Examples==
{{Website Icon}}
==Best Practices Resources==
{{Document Icon}}
==Trainings==
{{Video Icon}}


{{Citations}}


{{revhistinf}}

Hydraulics

2022-09-09T21:28:00Z

Pcampana:

__NOTOC__
----

The hydraulic design of a dam includes a knowledge of, but not limited to, the following foundational topics: pressurized and free-surface flow, uniform flow, gradually and rapidly varied flow, steady and unsteady flow, energy and momentum principles, energy losses, and cavitation. <ref name="HydDoS">[[Hydraulic Design of Spillways | Hydraulic Design of Spillways (EM 1110-2-1603)]]</ref>

==Hydraulic Design Criteria==
[paragraph here]

==Types of Evaluations==
[paragraph here]

*[[Hydraulic Performance of Spillways]]

*[[Hydraulic Performance of Outlet Works]]

*[[Dam Breach Inundation Analysis]]

*[[Scour Analysis]]

*[[Tailwater Modeling]]

==Types of Hydraulic Modeling==
*[[One-Dimensional Hydraulic Models]]

*[[Two-Dimensional Hydraulic Models]]

*[[Three-Dimensional Hydraulic Models]]

==Examples==
{{Website Icon}}
==Best Practices Resources==
{{Document Icon}}
==Trainings==
{{Video Icon}}


{{Citations}}


{{revhistinf}}

Hydraulics

2022-09-09T21:25:58Z

Pcampana:

Hydraulics

2022-09-09T21:24:51Z

Pcampana:

__NOTOC__
----

The hydraulic design of a dam includes a knowledge of, but not limited to, the following foundational topics: pressurized and free-surface flow, uniform flow, gradually and rapidly varied flow, steady and unsteady flow, energy and momentum principles, energy losses, and cavitation. <ref name="HydDoS">[[EM 1110-2-1603 Hydraulic Design of Spillways | Hydraulic Design of Spillways (EM 1110-2-1603)]]</ref>

==Hydraulic Design Criteria==
[paragraph here]

==Types of Evaluations==
[paragraph here]

*[[Hydraulic Performance of Spillways]]

*[[Hydraulic Performance of Outlet Works]]

*[[Dam Breach Inundation Analysis]]

*[[Scour Analysis]]

*[[Tailwater Modeling]]

==Types of Hydraulic Modeling==
*[[One-Dimensional Hydraulic Models]]

*[[Two-Dimensional Hydraulic Models]]

*[[Three-Dimensional Hydraulic Models]]

==Examples==
{{Website Icon}}
==Best Practices Resources==
{{Document Icon}}
==Trainings==
{{Video Icon}}


{{Citations}}


{{revhistinf}}

Hydraulics

2022-09-09T21:21:45Z

Pcampana:

__NOTOC__
----

The hydraulic design of a dam includes a knowledge of, but not limited to, the following foundational topics: pressurized and free-surface flow, uniform flow, gradually and rapidly varied flow, steady and unsteady flow, energy and momentum principles, energy losses, and cavitation. <ref name="HydDoS">[[EM 1110-2-1603 Hydraulic Design of Spillways | EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992]]</ref>

==Hydraulic Design Criteria==
[paragraph here]

==Types of Evaluations==
[paragraph here]

*[[Hydraulic Performance of Spillways]]

*[[Hydraulic Performance of Outlet Works]]

*[[Dam Breach Inundation Analysis]]

*[[Scour Analysis]]

*[[Tailwater Modeling]]

==Types of Hydraulic Modeling==
*[[One-Dimensional Hydraulic Models]]

*[[Two-Dimensional Hydraulic Models]]

*[[Three-Dimensional Hydraulic Models]]

==Examples==
{{Website Icon}}
==Best Practices Resources==
{{Document Icon}}
==Trainings==
{{Video Icon}}


{{Citations}}


{{revhistinf}}

Hydraulics

2022-09-09T21:18:48Z

Pcampana:

__NOTOC__
----

The hydraulic design of a dam includes a knowledge of, but not limited to, the following foundational topics: pressurized and free-surface flow, uniform flow, gradually and rapidly varied flow, steady and unsteady flow, energy and momentum principles, energy losses, and cavitation. <ref name="HydDoS">[[EM 1110-2-1603 Hydraulic Design of Spillways | Hydraulic Design of Spillways, USACE, 1992]]</ref>

==Hydraulic Design Criteria==
paragraph here

==Types of Evaluations==
paragraph here

*[[Hydraulic Performance of Spillways]]

*[[Hydraulic Performance of Outlet Works

*[[Dam Breach Inundation Analysis]]

*[[Scour Analysis]]

*[[Tailwater Modeling]]

==Types of Hydraulic Modeling==
*[[One-Dimensional Hydraulic Models]]
*[[Two-Dimensional Hydraulic Models]]
*[[Three-Dimensional Hydraulic Models]]

==Examples==
{{Website Icon}}
==Best Practices Resources==
{{Document Icon}}
==Trainings==
{{Video Icon}}


{{Citations}}


{{revhistinf}}

Hydraulics

2022-09-09T21:05:30Z

Pcampana: Created page with "__NOTOC__ ----  The hydraulic design of a dam includes a knowledge of, but not limited to, the following foundational topics: pressurized and free-surface flow, uniform flow, gradually and rapidly varied flow, steady and unsteady flow, energy and momentum principles, energy losses, and cavitation (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992). ==Types of Design..."

__NOTOC__
----

The hydraulic design of a dam includes a knowledge of, but not limited to, the following foundational topics: pressurized and free-surface flow, uniform flow, gradually and rapidly varied flow, steady and unsteady flow, energy and momentum principles, energy losses, and cavitation (EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992).

==Types of Design==
*[[New Dam]]
*[[Rehabilitation]]
*[[Decommissioning]]

==Typical Design Activities==
*[[Site Planning]]
*[[Permitting]]
*[[Constructability Review]]
*[[Engineering Oversight of Construction]]
*[[Potential Failure Modes Analysis]]

==Examples==
{{Website Icon}}
==Best Practices Resources==
{{Document Icon}}
==Trainings==
{{Video Icon}}


{{Citations}}


{{revhistinf}}