Plan Formulation Workshop

Objective

(225 mins) – In this hands-on workshop participants use the Muncie, Indiana example study data to create an HEC-FDA study from scratch to formulate and evaluate flood risk management alternatives. The workshop emphasizes formulation and evaluation of several flood risk management plans including levee, detention basin, nonstructural, combination detention basin and levee, levee and nonstructural, detention basin and nonstructural, and a plan with all the measures.

Downloadable Workshop Materials

Software Version

HEC-FDA Version 2.1 Beta will be used during this course.  Download the portable version of the software by following the instructions provided, here: Download the HEC-FDA Software. Detailed instructions are included on this page.

Workshop Datafiles

Download Zipped Workshop Datafiles:  

Introduction

In this final workshop, you'll put together everything you learned in previous workshops to build a model containing many alternatives. Less information will be provided for you so that you can test your knowledge of the software. A series of questions will follow and the solution project will be provided so you can check your answers.

Note: this workshop is separated into two parts. Part 1 involves modeling new components for a detention basin and nonstructural measures, up to the stage-damage function computation. Part 2 involves computation of EAD and EqAD. 

Part 1

Part 1 – Overview Table

Part 1 requires you to create an HEC-FDA Version 2 project from scratch with the data defined in Table 1.

Table 1 - Part 1 Study Data
Study DataNameDescription
TerrainMuncie TerrainThe Muncie terrain is the same file used the the hydraulic engineers in modeling the existing condition hydraulics.
Impact Areas SetMuncie Impact AreasImpact Area Set containing two impact areas (Left-Bank and Right-Bank)
HydraulicsExisting ConditionsExisting Condition Steady HDF. The hydraulic modeling was developed in steady-state condition. The native output files have been provided for use within HEC-FDA.
Frequency FunctionsExisting Condition LP3sFlow-Frequency LPIII distribution for a period of record (Record Length) of 48 years
Regulated-Unregulated Transform Functions*With-Project TransformThis regulated-unregulated transform function represents the attenuation of flashy flows provided by the modeled detention basin in the with-project condition that would be located just upstream of the impact area set.
Stage Transform Functions > Stage-Discharge Functions
  • Existing Condition Relationship
  • With-Project Condition
  • This stage-discharge function represents the relationship between stage and discharge for the without-project condition.
  • The stage-discharge function below represents the with-project condition. Observe that some stages are higher for a given discharge.
Lateral StructuresLevee948ftThis system response function is tied to a modeled levee in the with-project condition that is proposed for the Left-Bank impact area with a top elevation of 948 feet.

Economics > Occupancy Types

NSI_OccTypes

The Muncie occupancy types are the typical occupancy types referenced in the National Structure Inventory

Economics > Structure Inventories

  • Base_WOP_SI
  • Future_WOP_SI
  • WithProj_Base_SI
  • WithProj_Future_SI
  • base inventory for the Existing Conditions (without-project inventory)
  • future without-project inventory for the without-project future conditions (In the future year, the number of commercial structures has been doubled to reflect an economic forecast suggesting significant growth in the concentration of commercial activity in Muncie, In between the base and most likely future years.)
  • base year with-project inventory
  • future year with-project inventory (In the future year, the number of commercial structures has been doubled to reflect an economic forecast suggesting significant growth in the concentration of commercial activity in Muncie, In between the base and most likely future years.)

Economics > Aggregated Stage-Damage Functions

  • WOP Base Year
  • WOP Future Year
  • Nonstructural Base**
  • Nonstructural Future**
  • Computed for HEC-FDA Version 2 Workshops Existing Condition Stage-Damage Function (without-project)
  • Computed future without-project inventory for the without-project future conditions (number of commercial structures has been doubled to reflect an economic forecasting)
  • Computed for nonstructural inventory for the base year with-project conditions
  • Computed future with-project inventory for the with-project conditions most likely future year

*NEW function you have not entered in previous workshops. This is the first workshop with a Detention plan and the Regulated-Unregulated Transform Function represents the attenuation of flashy flows provided by the modeled detention basin. So, you'll need this new function for the Detention Plan.

**NEW aggregated stage-damage functions you have not computed in previous workshops. This is the first workshop with nonstructural measures and a new structure inventory is imported with changes to model residential elevations, non-residential floodproofing, and other nonstructural measures. So, you'll need this new function for the Nonstructural Plan.

Part 1 – Instructions

  1. Open the HEC-FDA Version 2 software

  2. Create a new study and set study properties. (Don't forget to update the discount rate).

  3. Import the Muncie Terrain file ("Terrain.hdf").

  4. Import the Muncie Impact Areas file ("ImpactAreaFinal.shp").

  5. Import the Steady State Muncie HEC-RAS Native Output hydraulics data ("Muncie.p10.hdf").

  6. Create Flow-Frequency Function.

    • From the Study Tree, right-click on Frequency Functions and select Create New Frequency Function. The Create Frequency Function opens as a tab.
      • Enter a name and a description for the frequency function. 

      • Select the Analytical radio button and enter the LPIII Parameters listed below. 

        MeanStandard DeviationSkewPeriod of Record
        3.7070.24-0.475 48
      • Click Save and Close.

  7. Enter the Regulated-Unregulated Transform Function (data displayed in Table 4). This is a NEW function you have not entered in previous workshops. This is the first workshop with a Detention plan and the Regulated-Unregulated Transform Function represents the attenuation of flashy flows provided by the modeled detention basin. So, you'll need this new function for the Detention Plan.

    • From the Study Tree, right-click on Regulated-Unregulated Transform Functions and select Create New Regulated-Unregulated Relationship. The Create New Regulated-Unregulated Relationship opens as a tab.

      • Enter a name for the relationship in the Name box (e.g., With-Project Transform), and enter a description for the relationship (e.g., This regulated-unregulated transform function represents the attenuation of flashy flows provided by the modeled detention basin in the with-project condition that would be located just upstream of the impact area set.).

      • Select the Triangular Distribution Type and copy the data displayed in Table 4 into the table in HEC-FDA.

        Inflow (cfs)Min Outflow (cfs)Most Likely Outflow (cfs)Max Outflow (cfs)
        1000100010001000
        2000200020002000
        4000400040004000
        7000700070007000
        100007100800010000
        1200080001000012000
        1300090001100013000
        15000115001300015000
        17000170001700017000
        20000200002000020000
        Table 4 - With-project Transform (Regulated-Unregulated Transform Function
      • Click Save.

  8. Enter the Without-project Condition Stage-Discharge Function (data in Table 5).

    • From the Study Tree, right-click on Stage-Discharge Functions and select Create New Stage-Discharge Relationship. The Create New Stage-Discharge Relationship opens as a tab. 

      • Enter a name and a description for the relationship. 

      • Use the information in Table 5 to create the new stage-discharge relationships for the without-project condition for the triangular distribution.

        Table 5 - Without-project Stage Discharge Function

        Loading

      • Click Save.

  9. Enter the With-project Condition Stage-Discharge Function (data in Table 6).

    • From the Study Tree, right-click on Stage-Discharge Functions and select Create New Stage-Discharge Relationship. The Create New Stage-Discharge Relationship opens as a tab.

      • Enter a name and a description and use the information in Table 6 to create the triangular distribution for the with-project condition.

        Table 6 - With-project Stage Discharge Function

        Loading

      • Click Save.

  10. Create Lateral Structure for the Levee Plan. NOTE: a fragility curve/system response function is utilized.

    • From the Study Tree, right-click on Lateral Structures and select, Create New Lateral Structure. The Create New Lateral Structure dialog opens as a tab. Use the Create New Lateral Structure dialog to add the Levee Plan:
      • Enter a name and a description for the levee plan (e.g., Name: Levee Plan; Description: With-project scenario for proposed levee for the left-bank with a top elevation of 948 feet).
      • Enter the Top of Levee Elevation: 948
      • Select the System Response Curve: User Defined
      • Enter the system response curve below:

        Loading

        You may need to delete any extra rows that contain default values.

      • Click Save to save the Levee Plan and add it to your project's Study Tree.

  11. Import Occupancy Types ("MuncieOccTypes20241125.txt").

  12. Import the Without-project Base Structure Inventory ("BaseMuncieStructsFinal.shp").

  13. Import the Future Without-Project Structure Inventory ("FutureMuncie.shp").

  14. Import the Nonstructural Structure Inventory for the Base Year ("BaseMuncieNonstructural.shp"). **NEW stage-damage function you have not computed in previous workshops. This is the first workshop with nonstructural measures and a new structure inventory is imported with changes to model residential elevations, non-residential floodproofing, and other nonstructural measures. So, you'll need this new function for the Nonstructural Plan.

    • Repeat the above process to import the "BaseMuncieNonstructural.shp".
      • Be sure to select the correct structure inventory file "BaseMuncieNonstructural.shp" (e.g., C:\Workshops\FDA\data\MuncieData\StructureInventories\base-year_with-project).
      • Select Ground Elevation and Foundation Height, and set the Ground Elevation Source from the Terrain file.

      • And then make the correct selections for the Import Attributes:

        Name

        Import Attributes Selection

        Structure IDTARGET_FID
        Occupancy Typeocctype
        Foundation Heightfound_ht
        Structure Valueval_struct
        Content Valueval_cont
        Vehicle Valueval_vehic
      • Click Next and Finish to import the structure inventory.

  15. Repeat the above process to import the Nonstructural Structure Inventory for the Future Year ("FutureMuncieNonstructural.shp"). **NEW stage-damage function you have not computed in previous workshops. This is the first workshop with nonstructural measures and a new structure inventory is imported with changes to model residential elevations, non-residential floodproofing, and other nonstructural measures. So, you'll need this new function for the Nonstructural Plan.

  16. Create and Compute four Stage-Damage Functions for the without and with-project the Base Year functions and the without and with-project Future Year functions. Use the information in Table 7 to create and compute the four new stage-damage relationships.

    Table 7 – Configuration Selections for Four Stage-Damage Functions
    Stage-Damage Function NameAnalysis YearWater Surface ElevationStructuresFrequency FunctionStage-Discharge Function
    WOP Base Year2031Existing Condition HydraulicsBase_WOP_SIExisting Conditions LPIIIWithout Project Rating Curve
    WOP Future Year2080Existing Condition HydraulicsFuture_WOP_SIExisting Conditions LPIIIWithout Project Rating Curve
    Nonstructural Base2031Existing Condition HydraulicsWithProj_Base_SIExisting Conditions LPIIIWithout Project Rating Curve
    Nonstructural Future2080Existing Condition HydraulicsWithProj_Future_SIExisting Conditions LPIIIWithout Project Rating Curve
    • From the Study Tree, under Economics, right-click on Aggregated Stage-Damage Functions and select Create New Stage-Damage Functions. The Create New Stage-Damage Functions opens as a tab.
      • Enter a name for the new function in the Name box (e.g., Existing Stage-Damage), and enter a description for the relationship (e.g., HEC-FDA Version 2 Workshops Existing Conditions Function).
      • Select the Computed radio button and enter the information identified in Table 7.
      • After you complete the configuration, click Compute Curves. Wait until HEC-FDA generates the curves. Scroll through the list of computed curves (you should generate 28 curves, 16 for the Left-Bank and 12 for the Right-Bank). 
      • Click Save and the created stage-damage functions for the without-project base conditions displays in the Study Tree.
    • Repeat these steps to create the other three stage-damage functions using the information provided in Table 7. Each function should generate 28 curves, 16 for the Left-Bank and 12 for the Right-Bank.

Part 1 – Discussion Questions

Test Your Knowledge - Question 1

Why is a regulated-unregulated transform function required to model a detention basin?

Test Your Knowledge - Question 2

Consider the shape of the regulated-unregulated transform function for the detention basin. The most-likely flow value dips and then returns to the baseline. Why does the most-likely flow value return to the baseline?

Test Your Knowledge - Question 3

In this example, the nonstructural measures are modeled by removing some structures in the with-project structure inventory. How might you modify the with-project structure inventory to model structure elevation/raising?

Return to top of page.

Part 2

Part 2 – Overview Table

Part 2 requires you to complete the HEC-FDA Version 2 model by creating Scenarios, Alternatives, and Alternative Comparison Reports as defined in Table 2.

Table 2 - Part 2 Study Data
Study DataExample Short NamesLong NamesDescriptions

Scenarios

  • WOP_Base
  • WOP_Future
  • Levee_Base
  • Levee_Future
  • DetentionBase
  • DetentionFuture
  • NS_Base
  • NS_Future
  • LeveeDetention_Base
  • LeveeDetention_Future
  • Levee_NS_Base
  • Levee_NS_Future
  • Detention_NS_Base
  • Detention_NS_Future
  • All_Base_Year
  • All_Future_Year
  • Without Base
  • Without Future
  • Levee Plan Base
  • Levee Plan Future
  • Detention Plan Base
  • Detention Plan Future
  • Nonstructural Plan Base
  • Nonstructural Plan Future
  • Levee & Detention Plan Base
  • Levee & Detention Plan Future
  • Levee & Nonstructural Plan Base
  • Levee & Nonstructural Plan Future
  • Detention & Nonstructural Plan Base
  • Detention & Nonstructural Plan Future
  • All Measures Base Year
  • All Measures Future Year
  • Without-project, base year
  • Future without-project most-likely future year
  • Levee only with-project, base year
  • Levee only with-project, future year
  • Detention only with-project, base year
  • Detention only with-project, future year
  • Nonstructural Plan only with-project, base year
  • Nonstructural Plan only with-project, future year
  • Levee and Detention with-project, base year
  • Levee and Detention with-project, future year
  • Levee and Nonstructural with-project, base year
  • Levee and Nonstructural with-project, future year
  • Detention and Nonstructural with-project, base year
  • Detention and Nonstructural with-project, future year
  • All measures for the Base Year
  • All measures for the Future Year

Alternatives

  • WOP
  • LeveeOnly
  • DetentionOnly
  • NS_Only
  • Levee_Detention
  • Levee_NS
  • Detention_NS
  • All
  • Without Project
  • Levee Only Plan
  • Detention Only Plan
  • Nonstructural Only Plan
  • Levee and Detention Plan
  • Levee and Nonstructural Plan
  • Detention and Nonstructural Plan
  • Levee, Detention, and Nonstructural Plan
  • Without-project base year and most-likely future year
  • Levee only with-project base year and most-likely future year
  • Detention only with-project base year and most-likely future year
  • Nonstructural only with-project base year and most-likely future year
  • Levee and Detention with-project base year and most-likely future year
  • Levee and Nonstructural with-project base year and most-likely future year
  • Detention and Nonstructural with-project base year and most-likely future year
  • Levee, Detention, and Nonstructural with-project base year and most-likely future year

Part 2 – Instructions

Continue using the FDA study you created in Part 1.

  1. Create the scenarios for the two analysis years for each plan. Use the information in Table 8.

    Threshold Stage

    Recall the threshold stage is the index by which system performance statistics are calculated. Also, FDA will not automatically identify the threshold stage for impact areas without levees for with-project condition scenarios, the user will need to specify those stages. 

    Table 8 - Scenarios for Workshop 6
    Scenario (Short Names)Analysis YearStage-Damage FunctionsFrequency Relationship*Regulated-Unregulated Flow*Stage-Discharge*Lateral StructuresThreshold Stage**
    WOP_Base2031WOP Base YearExisting Conditions LPIIINoneWithout Project Rating CurveNoneCompute Default Thresholds
    WOP_Future2080WOP Future YearExisting Conditions LPIIINoneWithout Project Rating CurveNoneCompute Default Thresholds
    Levee_Base2031WOP Base YearExisting Conditions LPIIINoneWith-Project Rating CurveLevee (Left-Bank Only)Left-Bank: Levee
    Right-Bank: WOP_Base, Right-Bank
    Levee_Future2080WOP Future YearExisting Conditions LPIIINoneWith-Project Rating CurveLevee (Left-Bank Only)Left-Bank: Levee
    Right-Bank: WOP_Future, Right-Bank
    DetentionBase2031WOP Base YearExisting Conditions LPIIIWith-Project TransformWithout Project Rating CurveNoneLeft-Bank: WOP_Base, Left-Bank
    Right-Bank: WOP_Base, Right-Bank
    DetentionFuture2080WOP Future YearExisting Conditions LPIIIWith-Project TransformWithout Project Rating CurveNoneLeft-Bank: WOP_Future, Left-Bank
    Right-Bank: WOP_Future, Right-Bank
    NS_Base2031Nonstructural BaseExisting Conditions LPIIINoneWithout Project Rating CurveNoneLeft-Bank: WOP_Base, Left-Bank
    Right-Bank: WOP_Base, Right-Bank
    NS_Future2080Nonstructural FutureExisting Conditions LPIIINoneWithout Project Rating CurveNoneLeft-Bank: WOP_Future, Left-Bank
    Right-Bank: WOP_Future, Right-Bank
    LeveeDetention_Base2031WOP Base YearExisting Conditions LPIIIWith-Project TransformWith-Project Rating CurveLevee (Left-Bank Only)Left-Bank: Levee
    Right-Bank: WOP_Base, Right-Bank
    LeveeDetention_Future2080WOP Future YearExisting Conditions LPIIIWith-Project TransformWith-Project Rating CurveLevee (Left-Bank Only)Left-Bank: Levee
    Right-Bank: WOP_Future, Right-Bank
    Levee_NS_Base2031Nonstructural BaseExisting Conditions LPIIINoneWith-Project Rating CurveLevee (Left-Bank Only)Left-Bank: Levee
    Right-Bank: WOP_Base, Right-Bank
    Levee_NS_Future2080Nonstructural FutureExisting Conditions LPIIINoneWith-Project Rating CurveLevee (Left-Bank Only)Left-Bank: Levee
    Right-Bank: WOP_Future, Right-Bank
    Detention_NS_Base2031Nonstructural BaseExisting Conditions LPIIIWith-Project TransformWithout Project Rating CurveNoneLeft-Bank: WOP_Base, Left-Bank
    Right-Bank: WOP_Base, Right-Bank
    Detention_NS_Future2080Nonstructural FutureExisting Conditions LPIIIWith-Project TransformWithout Project Rating CurveNoneLeft-Bank: WOP_Future, Left-Bank
    Right-Bank: WOP_Future, Right-Bank
    All_Base_Year2031Nonstructural BaseExisting Conditions LPIIIWith-Project TransformWith-Project Rating CurveLevee (Left-Bank Only)Left-Bank: Levee
    Right-Bank: WOP_Base, Right-Bank
    All_Future_Year2080Nonstructural FutureExisting Conditions LPIIIWith-Project TransformWith-Project Rating CurveLevee (Left-Bank Only)Left-Bank: Levee
    Right-Bank: WOP_Future, Right-Bank

    * Unless noted (e.g., "Left-Bank Only") the above files are assigned to both impact areas (Left-Bank and Right-Bank).
    ** Recall the threshold stage is the index by which system performance statistics are calculated and there are four different cases for determining the threshold value (please review the Target Threshold section of the Scenarios page in HEC-FDA User Manual for more information).


    1. Compute the two without-project scenarios and view the summary results.
    2. Record the Without-project Base Year (e.g., WOP_Base) and Without-project Future Year (e.g., WOP_Future) the Performance Parameters, Threshold Value for the following each analysis year (2031 and 2080) and impact area (Left-Bank and Right-Bank).
    3. Create the remaining With-Project Scenarios. Using the recorded Threshold Values calculated in Step 1 (a) and the information in Table 8 to create and compute the with-project scenarios.
    4. For the impact areas in the with-project scenarios that do not contain a levee, manually enter and set the threshold stage, by unchecking the Calculate Default Threshold checkbox and entering the project performance threshold in the Threshold Stage box. Be sure to save the entered threshold stage (in Version 2.0, click Set) before navigating between impact areas.

      Warning!

      This quick how-to does not show you the value you enter for your study, just how-to find the value (may or may not match your study results). As identified in Table 8 you must use the corresponding analysis year and impact area for manually entering the Threshold Stage. 

      Quick How-to find a without-project scenario's threshold stage
  2. Create the Alternatives. Use the information in Table 9 to create and compute the 8 alternatives.
    Table 9 - Alternatives for Workshop 6
    Alternative NameBase Year ScenarioFuture Year Scenario
    Without-ProjectWithout Base Year (2031)Without Future Year (2080)
    LeveeOnlyLevee Plan Base Year (2031)Levee Plan Future Year (2080)
    DetentionOnlyDetention Plan Base Year (2031)Detention Plan Future Year (2080)
    NSonlyNonstructural Plan Base Year (2031)Nonstructural Plan Future Year (2080)
    Levee_DetentionLevee & Detention Plan Base Year (2031)Levee & Detention Plan Future Year (2080)
    Levee_NSLevee & Nonstructural Plan Base Year (2031)Levee & Nonstructural Plan Future Year  (2080)
    Detention_NSDetention & Nonstructural Plan Base Year (2031)Detention & Nonstructural Plan Future Year  (2080)
    All_MeasuresAll Measures (2031)All Measures (2080)

  3. Create the Alternative Comparison Report. Use the information in Table 10 to create the alternative comparison report.

    Table 10 - Alternative Comparison Report
    Alternative Comparison Report NameWithout Project SelectionWith Project Selection




    Comparison




    Without-Project

    		LeveeOnly
    DetentionOnly
    NSonly
    Levee_Detention
    Levee_NS
    Detention_NS
    All_Measures


Part 2 – Discussion Questions

Test Your Knowledge - Question 4

Which plan minimizes residual economic damages?

Test Your Knowledge - Question 5
Why is EqAD negative on the right-bank for the levee-only plan?
Test Your Knowledge - Question 6

Inducements from a levee must be mitigated. How much inducement (i.e., increased stage by X amount) must there be before mitigation is required?

Conclusion

Download the solution project below to compare to your project:

Review the best answers to test your FDA knowledge questions and compare with yours to see how you did!

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Test Your Knowledge - Question 1

Why is a regulated-unregulated transform function required to model a detention basin?

Answer: Flows are diverted from the channel to detention basin, which causes flow in the with-project condition to decrease for a given flow in the without-project condition.

Test Your Knowledge - Question 2

Consider the shape of the regulated-unregulated transform function for the detention basin. The most-likely flow value dips and then returns to the baseline. Why does the most-likely flow value return to the baseline?

Answer: This represents the detention basin reaching its volume capacity. At this point, the detention basin no longer provides flood risk reduction benefits. 

Test Your Knowledge - Question 3

In this example, the nonstructural measures are modeled by removing some structures in the with-project structure inventory. How might you modify the with-project structure inventory to model structure elevation/raising?

Answer: Elevated structures can be modeled by increasing the foundation height or foundation elevation column in the with-project structure inventory.

Note: Your results may not exactly match the results shown here. That's a product of variation in the software since this workshop was created and does not indicate that you did something wrong. Your results should follow the same trends and the values should be somewhat close to the ones shown below.

Test Your Knowledge - Question 4

Which plan minimizes residual economic damages?

Answer: The Levee-Nonstructural plan has a with-project EqAD of  $603,051.32, which is lowest among all plans - unless you combine all measures into an All-measure plan

Test Your Knowledge - Question 5

Why is EqAD negative on the right-bank for the levee-only plan?

Answer: Because the levee causes increased stages for a given discharge. The right-bank has no levee, so higher stages mean increased damages. The left-bank has a levee, so the higher stages don't reach the left-bank.

Test Your Knowledge - Question 6

Inducements from a levee must be mitigated. How much inducement (ie increased stage by X amount) must there be before mitigation is required?

Answer: A recent court case determined that any amount of induced stage greater than 0 triggers a requirement for mitigation.

Related Topics

For the list of resources below, either select a specific page to view the related information, or click on a page label to see all the pages for a specific topic (e.g., fda_help_resources).