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OpenFlows | Water Infrastructure
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OpenFlows | Water Infrastructure
OpenFlows | Water Infrastructure Wiki Modeling a Connection to an Existing System
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    • OpenFlows | Water infrastructure Wiki
    • +OpenFlows CivilStorm
    • +OpenFlows CulvertMaster
    • +OpenFlows FLOOD
    • +OpenFlows FlowMaster
    • +OpenFlows HAMMER
    • +OpenFlows PondPack
    • +OpenFlows SewerCAD
    • +OpenFlows SewerGEMS
    • +OpenFlows StormCAD
    • +OpenFlows WaterCAD
    • -OpenFlows WaterGEMS
      • +Calculations - Bentley WaterGEMS
      • Change the size of flow arrows in ArcGIS Pro
      • +Conversion - Bentley WaterGEMS
      • Error message opening program: “This implementation is not part of the Windows Platform FIPS validated cryptographic algorithms.”
      • Error publishing i-model: Could not add file level provenance
      • Error trying to to Add Joins or Remove Joins: Object reference not set to an instance of an object
      • +General - BENTLEY WATERGEMS
      • +Help and Documentation - Bentley WaterGEMS
      • How to add element labels in ArcGIS Pro
      • How to determine if a condition or action is being shared with other controls?
      • How to remove bends from a pipe or conduit
      • How to troubleshoot system deficiencies in a hydraulic model, like flooding, low pressures, or tank or pipe size
      • Image background file causes application to crash without an error message
      • +Installation - Bentley WaterGEMS
      • +Integration - Bentley WaterGEMS
      • +Interchange - Bentley WaterGEMS
      • +Layout and Data Input - Bentley WaterGEMS
      • +Libraries/Catalogs - Bentley WaterGEMS
      • +Licensing - Bentley WaterGEMS
      • -Modeling - Bentley WaterGEMS
        • "Cannot solve network hydraulic equations" or other failure when using parallel variable speed pumps or VSPB
        • "Initialize Connection Error: Unsupported geometry type for sync-out operations found in table "xx" " when syncing out using modelbuilder
        • Accounting for elevation difference in scaled pipe lengths
        • Accounting for well drawdown
        • +After exporting a model to DXF, text appears shifted in the resulting DXF file.
        • Annotation or Color Coding not updating when scrolling through Time Browser or Changing Scenarios
        • Application crash with non-English characters (Hebrew, Arabic, etc) in background image file or folder name
        • Applying PDD only to a portion of a node's demand, or to specific demand patterns
        • Associating multiple customer meters to one element using the global edit function
        • Automatically assign the Zone property based on calculated pressure zones
        • Background layer linework does not appear correct, is badly aligned, or jumps around when zooming and/or panning.
        • Benefits of using variable speed pump batteries (VSPB) element and how it works
        • Calculating available flow at a hydrant
        • Calculating headloss through a hydrant lateral
        • Calculating Net Positive Suction Head (NPSH)
        • Calibrating a model based on hydrant flow tests
        • Can a node be a constituent source?
        • Can I start trace analysis at other time than simulation time?
        • Can I use Darwin Designer for the EPS analysis?
        • Can WaterCAD or WaterGEMS perform a transient analysis?
        • Changing drawing style for better viewing of element symbols and annotations
        • Changing symbol size, text height, or line width for elements in a model
        • Changing the order of Flushing Events or Flushing Areas
        • Citect is not available when running as 64-bit
        • Compacting data causes element display issues
        • Computing Darwin Calibrator run returns the user notification "Must have at least one adjustment group…"
        • Conducting Flushing Studies in WaterGEMS and WaterCAD
        • Constant Power pump definitions with Variable speed pumps
        • Contours considering elements not included in the contour selection set
        • Controls disappear after being input
        • Controls for alternating or cycling between multiple pumps
        • Creating a new model inside the ArcMap or ArcGIS Pro integrated platform
        • Creating Custom Reports
        • Critical Valves Analysis
        • Customer Meter Elements and the External Customer Meter Data Manager
        • Darwin Calibrator error "An error occurred when trying to calculate or validate the model..."
        • Darwin Calibrator Performance Improvement Tips for Large Models
        • Darwin Designer manual design run solution diameters don't match the manual selection from the Design Groups tab
        • Deleted elements still show in FlexTable and/or drawing pane
        • Demand inversing in SCADAConnect Simulator
        • Difference between Initial and base water quality constituent concentration types
        • EPANET time-based controls are ignored when importing an INP file into WaterGEMS or WaterCAD
        • Error computing Flushing analysis: "Object reference not set to an instance of an object."
        • Error computing in SCADAConnect Simulator: Object reference not set to an instance of an object
        • Error connecting to a database source in SCADAConnect Simulator, "WaterGEMS Problem" - "The data source is specified but is not available"
        • Error filtering on Control Set: Object reference not set to an instance of an object
        • Error importing old model file: "Object reference not set to an instance of an object"
        • Error message generated when loading background file
        • Error message generating report: Could not find file "C:\Program Files (x86)\Bentley\WaterCAD\x64\QuadrantCurvesPredefined.txt"
        • Error message when trying to select more than one element
        • Error message: The last multiplier in a pattern must match the starting multiplier
        • Error opening model: "1: no such column: IdahoPipeResults_PipeUnifiedLength"
        • Error opening model: Invalid character in the given encoding
        • Error running Darwin Designer - Value does not fall within the expected range
        • Error validating model or running a fire flow analysis: "Object reference not set to an instance of an object"
        • Error validating or computing model: "Pipe references deleted or inactive node"
        • Error when computing or validating: Invalid demand adjustment demand pattern
        • Error when computing: Reference to a deleted or inactive downstream pipe
        • Error when opening model files: The specified path, file name, or both are too long.
        • Error when running a criticality analysis: Object reference not set to an instance of an object.
        • Error when running Flushing analysis: Reference to a deleted or inactive element of interest
        • Extending service area polygons to fill flow boundary layer
        • Filtering a Flextable on Zone = "None"
        • Filtering controls on element not working with composite condition or action
        • Fire flow analysis at the time of minimum pressure (EPS Fire Flow Analysis Tool)
        • Fire flow analysis of multiple hydrants at the same time
        • Flushing error message - Flushing event order duplicates at least one other flushing event
        • General Pump Selection Process
        • Genetic algorithm parameters in Darwin Designer and Darwin Calibrator
        • Getting data and setting up for a Constituent Analysis in WaterGEMS and WaterCAD
        • How are flow results reported for a pipe when using taps and laterals on a customer meter element?
        • +How are pumps handled in each OpenFlows product?
        • How can I display Post Calculation Processor results for different scenarios?
        • How can I global edit the pipe material and have the roughness update?
        • How can I make a PRV, PSV, FCV or TCV valve active after closing it with controls?
        • How can I model a backflow preventer?
        • How can the quality of SCADA data be accounted for with SCADA signals in WaterGEMS?
        • How can you change the background and foreground colors in the drawing pane?
        • How can you move an element when working with a model in the ArcGIS environment?
        • How do each of the LoadBuilder methods work?
        • How do i delete orphan nodes?
        • How do I model a PRV with a bypass?
        • How do you consider only a selection set of elements with LoadBuilder?
        • How do you find or change the friction method used in WaterGEMS and WaterCAD
        • How does the Pipe Renewal Planner tool decide which criticality segment a pipe belongs to?
        • How does the Pressure Reducing Valve (PRV) work in WaterGEMS and WaterCAD?
        • How does the Pressure Sustaining Valve (PSV) work in WaterGEMS and WaterCAD?
        • How does WaterGEMS and WaterCAD calculate the water age in a looped system?
        • How to "save as" or copy a project in the ArcMap environment
        • How to Batch Morph nodes from one type to another
        • How to convert a TCV GPV or PBV to an Isolation Valve using Skelebrator
        • How to define real-time custom queries in SCADAConnect
        • How to import and export controls between models in WaterCAD and WaterGEMS
        • How to manually generate a system head curve
        • How to model a Combination Pressure Reducing Valve (PRV) and Pressure Sustaining Valve (PSV)
        • How to protect elements which are part of control sets in Skelebrator
        • How to use the "Hydrant Status" property in WaterGEMS and WaterCAD
        • In what alternative can I change the starting status or Status(Initial) of a pipe?
        • Increasing headloss for all pipes or a set of pipes
        • Intermediate Time Steps
        • Internal Error in AutoCAD: eNotOpenForWrite
        • Is it possible to make a child scenario/alternative into a base scenario/alternative?
        • Is it possible to reproject a model to a different coordinate system?
        • Junction vs. Hydrant
        • LoadBuilder demand allocation for customer meters with taps and laterals
        • LoadBuilder Error: A very high number of Usage Types were found
        • Memory error when using Terrain Extractor
        • Mixing Chlorine and Chloramines
        • Modeling a Connection to an Existing System
        • Modeling a Constant Headloss
        • Modeling a control condition based on the sum of flow in multiple pipes
        • Modeling a Tank with an Overflow
        • Modeling devices and components that are not explicitly available as an element
        • Modeling District Metered Areas (DMAs)
        • Modeling Fixed Inflow from a Marginal Source
        • Modeling intermittent water supply
        • Modeling minor losses at a valve or a tee
        • Modeling multiple VSPs where only one turns on at a time
        • Modeling other fluids or fluid temperatures
        • Modeling private customer pump stations
        • Modeling PRV / PSV controlled by pressure at remote location in the model
        • Modeling Surge Relief Valves (SRV) in WaterGEMS or WaterCAD
        • Modeling top fill tanks and throttling inlet valves
        • Modeling Turbidity in water systems
        • New demands or customer meter assignments not showing up after running LoadBuilder
        • New Flextable features in 08.11.06.58+ (Water products) and 08.11.05.113+ (Storm/Sewer products)
        • No constituents available in the constituent alternative
        • Nodes missing from or listed multiple times in the Demand Control Center
        • Opening a new or existing model in an existing MXD
        • Opening an existing hydraulic model when integrated with ArcMap or ArcGIS Pro
        • Pipe fill or drain time in WaterGEMS and WaterCAD
        • Positive volume vs negative volume in Totalizing Flow Meter
        • Preparing for and Responding to Water System Emergencies
        • Pump curve linear interpolation
        • Pump selection for a closed system
        • Pump Station and Pump Combination Curves
        • Pumping Over High Points
        • Query based selection sets not updating in various tools such as color coding and annotations
        • Rapid flow oscillation between hydraulically close tanks
        • Roughness value changing to the default value after splitting the pipe
        • Select end nodes of pipes in a selection set
        • Selecting hydraulic elements to view element properties in the ArcMap and ArcGIS Pro platforms
        • Selecting junctions based on type of associated Customer Meters
        • Selecting multiple elements for a selection set
        • Simulate bypass flow through a pump that is turned off
        • Simulating a Fire Response in SCADAConnect Simulator or WaterOPS
        • Skelebrator Skeletonizer branch collapsing only updates customer meter associated element fields for the active scenario
        • Start and stop nodes are not exported in "Sync Out" using ArcGIS Geodatabase features with ModelBuilder
        • System.ArgumentException: Font '<Font Name>' does not support style 'Regular'
        • Tips for improving performance of all-pipe models linked to a GIS
        • Tips for Water Loss Management and Leak Detection
        • Tracking cumulative length (stationing) for a branched water network
        • Troubleshooting and Understanding LoadBuilder
        • Troubleshooting Controls in WaterCAD and WaterGEMS
        • Troubleshooting negative pressures at pumps, junctions, & other node elements
        • Troubleshooting Pressure Dependent Demands with a network unbalanced user notification
        • Understanding System Head Curves in WaterGEMS, WaterCAD, and SewerCAD
        • Understanding the Fire Flow (Needed) and Fire Flow (Upper Limit) fields for an Automated Fire Flow analysis
        • User notification: "One or more patterns has a time step that does not coincide with the calculation hydraulic time step."
        • Using "Clock Time" and "Time From Start" Controls
        • Using a Flow Control Valve (FCV)
        • Using LoadBuilder to assign Customer Meters to the nearest pipe using taps and laterals
        • Using Multi-Species Extension (MSX) for advanced water quality modeling
        • Using pump flow test data to create a pump curve
        • Using Pump Performance Studies to analyze pump performance and efficiency
        • Using SCADAConnect Simulator
        • Using Spot Elevations
        • Using the LIKE and IN Operators with queries to filter on text fields such as label
        • Using the Pressure Zone Manager
        • Using the zero diameter option in Darwin Designer
        • Using Water Quality Batch run for multi-point trace and multiple constituents
        • Valve Type field assumptions and use with a TCV
        • Viewing and global editing a list of Demands
        • VSP or VSPB not properly maintaining target hydraulic grade
        • Water Model Calibration Tips
        • What file types are supported for background layers in the standalone platform?
        • What happens when a tank becomes empty or full? (altitude valve)
        • What is the asterisk "*" column mean in relation to alternatives?
        • What is the difference between Darcy-Weisbach roughness coefficients e and f, and Bed Roughness Ks or K?
        • What is the purpose of the "DMA Status" property in WaterGEMS and WaterCAD?
        • Why can’t I specify both head and flow at a pump?
        • Why do I see such a large headloss through my FCV, PSV or PRV?
        • Why is there an energy cost associated with a tank?
      • Modeling scenarios with different demand conditions
      • +N/A - Bentley WaterGEMS
      • +New Features and Enhancements for OpenFlows products
      • No items available in Usage Field pulldown menu when adding demands or loading in LoadBuilder
      • +Other - Bentley WaterGEMS
      • +Output and Reporting - Bentley WaterGEMS
      • +Output/Results Presentation - Bentley WaterGEMS
      • SCADAConnect Simulator adding a "#" symbol to SQL query
      • Sorting by label is not in the expected order
      • Unexpected, automatic updating of model when working on the MicroStation integrated platform for OpenFlows Products
      • Using ArcGIS Pro Snapping tool to create elements in the ArcGIS Pro platform
      • Using Skelebrator to reduce the number of pipes in a model
      • Using Text, Line, and Border feature
      • Using Variable Speed Pumps in WaterGEMS and WaterCAD
      • What does node elevation represent in WaterCAD, WaterGEMS and HAMMER?
      • What is the difference between the Schematic and Scaled drawing mode?
      • What's New in WaterGEMS and WaterCAD CONNECT Edition Update 2
      • What's New in WaterGEMS and WaterCAD CONNECT Edition Update 2 - build 10.02.01.06
      • What's New in WaterGEMS, WaterCAD, and WaterOPS CONNECT Edition Update 3 (10.03.05.03 & 10.03.05.05)
      • What's New in WaterGEMS, WaterCAD, and WaterOPS CONNECT Edition Update 3.4 (version 10.03.04.05)
      • What's New with WaterGEMS and WaterCAD CONNECT Edition Update 1
      • Workflow for Age, Constituent, and Trace analyses using WaterGEMS and WaterCAD
    • +OpenFlows WaterSight
    • +OpenFlows WaterOPS
    • +OpenFlows SewerOPS
    • +Bentley HEC-PACK
    • +General
    • +Help and Documentation
    • +Installation
    • +Licensing / Activation
    • +Integration
    • +Modeling
    • +Layout and Data Input
    • +Calculations
    • +Output and Reporting
    • +Other
    • +OpenFlows Product TechNotes And FAQs
    • Check boxes do not appear in tables such as Control Sets dialog
    • Consuming ContextCapture production files within your hydraulic model
    • Convergence NOT achieved Message when computing StormCAD or SewerCAD model
    • Converting Junctions or Hydrants to Isolation Valves
    • Displaying Shapefile Labels (Text) As a Background
    • Enhancing OpenFlows multi-user workflows with ProjectWise Share
    • Error "System.TypeInitializationException"
    • Error 32768 when opening model while integrated with ProjectWise
    • Errors installing patch set
    • Error when opening PondPack: "Object reference not set to an instance of an object" or "Application has generated an exception that could not be handled."
    • Error when saving or validating: System.AccessViolationException: Attempted to read or write protected memory.
    • File Open Dialog does not appear
    • Flextable Report of Multiple Element Types
    • Get to know OpenFlows CONNECT Edition
    • Get to know WaterGEMS, WaterCAD and HAMMER CONNECT Edition
    • How do I import/export multiple point pump curve pump definitions into a model using ModelBuilder?
    • How do you save backup files, so they save at different times and multiple levels?
    • How does the intermediate geodatabase (.MDB or .GDB) file function with ArcMap and ArcGIS Pro integration?
    • How to Delete Engineering Libraries if you get a message about a Read-only database
    • How to receive alerts on new version availability?
    • How to register DAO360.dll or a dll file?
    • How to search using wild cards on a sqlite type of database
    • How to See Hebrew or Arabic text in a .DXF file that was exported from WaterGEMS/WaterCAD
    • Hydraulic grade discontinuity at steep pipes or across nodes (frontwater analysis)
    • I get a red user notification that says, "Inlet guttter mannings n should be greater than 0".
    • Importing .HLB library files from old product versions into format used in the V8 product versions
    • Importing External Data in Geographic Coordinate Systems
    • Importing storm data and other library information from older versions
    • Changing element symbols in the AutoCAD platform
    • Interchange
    • Locating OpenFlows product error log file
    • Locating OpenFlows Product Version Number and License Information
    • Model backward / forward compatibility
    • Multi-user Workflows
    • Modeling a closed loop system
    • Modeling a flow split (diversion) with the SewerCAD or StormCAD numerical solver
    • Modeling turbine load acceptance plus load rejection
    • Multiple CN numbers for a catchment and multiple catchments with a single outlet node
    • Network Navigator Trace Upstream/Downstream does not return any elements
    • OpenFlows software numerical solver theory
    • Percent Connected Impervious Areas and Percent Unconnected Impervious Areas
    • Performing a hydrosanitary design in WaterGEMS or WaterCAD
    • PondPack user notification: "The composite outlet structure is either not selected or deleted."
    • PondPack: How to perform a critical duration analysis?
    • Pressure pipe vs. conduit between pump and wetwell
    • Print Preview > Fit to Page shows blank page
    • Properties not working when using MicroStation integration with ProjectWise
    • Properties, Flextables, user notifications, or other dialog is missing or will not open in standalone
    • Properties, user notifications, or other tool managers not showing up in Integrated version of AutoCAD
    • Reusing Pump Definitions (Import / Export)
    • Reversing orientation of Pipes and Conduits in Bulk
    • Saving a hydraulic model when using the AutoCAD platform (i.e. integrated)
    • Important License Update for OpenFlows Users
    • Setting the invert elevation for multiple conduits coming into one manhole
    • Simple Controls vs. Logical Controls
    • Sorting and relabeling a flextable based on upstream-downstream order
    • Source of the default Specific Speed for pumps and turbines
    • Step by step procedure for finding the curb length needed to capture 100% of gutter flow in a curb inlet with a continuously depressed gutter with no clogging
    • System.Reflection.TargetInvocationException crash when trying to open the application
    • Test Wiki Page - A1
    • Text, cells/blocks and line styles do not display correctly in a DXF background layer
    • The flow annotation (label) in my WaterGEMS for ArcMap isn't reflecting the value displayed in my Geotable or Flextable
    • The total area in the CN/Area Collection does not equal the total catchment area
    • Time tolerance setting in SCADAConnect Simulator
    • Troubleshooting ArcMap / ArcGIS Integration
    • Turbine Efficiency
    • Understanding Flow (Additional Subsurface) and Flow (Additional Carryover)
    • Upcoming training and release dates for OpenFlows products
    • User notification "Downstream TW out of range..."
    • User notification "Pump exceeds the maximum operating point specified for the pump curve"
    • User Notification - The captured surface flow at this node does not connect a valid subsurface network. The flow is lost from the system.
    • User Notification: "There is an error in the data for this pipe. The associated data is incorrect"
    • User Notification: Cross section maximum elevation is above the maximum headwater elevation
    • User Notifications: "Pump On elevation is not in the range of upstream ...." and "Off elevation of pump is lower than ..."
    • Using batch pipe split to fix nodes that overlay a pipe instead of connecting to it
    • Using PondMaker with different tailwater for each return event
    • Valve "Status (Initial)" Definitions
    • Velocity Calculations and the Average Velocity Methods in SewerCAD and StormCAD
    • Viewing graph data for multiple scenarios
    • Water age results in a pipe are different from the age in the downstream junction
    • Water Loss Management
    • Water quality Analysis during transient events
    • WaterGems Tips
    • What are the limitations of importing/exporting EPANET files?
    • What is the dotted line that is associated with the isolation valves? Can I turn them off?
    • What's new in WaterCAD, WaterGEMS and HAMMER V8i SELECTseries 6 with CONNECT Integration?
    • What's New in WaterOPS CONNECT Edition 2.3 (Build 10.02.03.06)
    • When the user changes the fluid, why doesn't the calculated pump head change?
    • Working From Home With Your OpenFlows Software
    • "An error occurred when trying to calibrate the model"
    • "COM Error Not Documented" when opening OpenFlows product
    • "Default license feature configuration not found. Product features may be limited. Please run the License Administrator."
    • "The Depth-Flow, Depth-Flow (Simulated Variable Speed) and Volume-Flow pump definition types are unsupported"
    • "Unable to assign attribute ... for element because enumeration value ... is not valid."
    • Add custom data to profile with User Data Extensions
    • After computing a model with the SWMM solver, what does the following warning mean: "Maximum depth increased for node CB-XX"?
    • After computing the model, the pump efficiency results are listed as N/A
    • After running loadbuilder I get a message that says "The layer <Layer_Name> could not be opened."
    • At what point does OpenFlows product license usage start when integrated with MicroStation?
    • Background image quality poor on some computers or Crash when opening models with background layers
    • Blocky stepwise pattern is displayed instead of a continous smooth pattern that was entered when using the SWMM engine
    • Can User Data Extensions be shared between elements in a model?
    • Catch basins imported as manholes from LandXML
    • Change in results before turbine load rejection occurs
    • Custom quadrant curve not being recognized
    • Date-time based query not working
    • Default license configuration not retaining setting
    • Do inactive elements count against the license count?
    • Does HAMMER support initially negative pressures?
    • Does the friction method affect local minor loss in pipes?
    • Does WaterGEMS and WaterCAD report pressures as gauge pressure or absolute pressure?
    • Efficiency Curve vs. Wire-to-Water Efficiency Curve
    • Error importing a LandXML file from StormCAD into Civil 3D "A pipe or conduit had an unsupported geometry"
    • Error message when validating model: "Elevation (Relative) values within the Irregular shape definition must be non-negative."
    • Error message: "Unrecognized database format ..." when trying to open model
    • Error Saving: "Custom results path is invalid"
    • Find if pump operates off of the pump curve during an automated fire flow scenario
    • Flow arrows are not included in an exported DGN file when using the Save Symbology option in the MicroStation platform
    • Flow from pump is delayed after pump startup
    • GeoPak - StormCAD errors - GEOPAK runtime environment not found / Error writing GEOPAK/PowerCivil node
    • HEC-22 2nd edition energy loss calculations with the Implicit solver
    • How are "pipe sets" and "nodes of interest" used in a flushing analysis to get auxiliary results at other elements?
    • How can I see the amount of inflow or outflow occuring for a particular surge tank during the transient simulation in HAMMER?
    • How do I filter a column in my flextable using a custom query that retrieves all records with a <None> attribute?
    • How do I know if and when my pond is overtopping and how to quantify it?
    • How do I save my model files when working in the ArcMap or ArcGIS Pro platform?
    • How do the channel slopes and velocity effect the headloss formulas in SewerCAD and StormCAD?
    • How does StormCAD handle gutter flow from an active catch basin to an inactive catch basin?
    • How does the diameter of an isolation valve effect the calculated results?
    • How to add comments on custom pump and turbine quadrant curves
    • How to find volume of water coming from a trace element?
    • How to open a .PRNX report file created on exporting custom report in OpenFlows product
    • Hydropneumatic tank atmospheric pressure not changing results
    • Hydropneumatic tank profile animation and time history shows zero gas volume
    • Initial surge when using turbine load acceptance operating case
    • Initial turbine HGL the same as the final HGL after load acceptance
    • Irregular Weir Flow Calculations in a Composite Outlet Structure
    • Is it possible to create old PondPack style text reports?
    • Is it possible to have a storm event start at a different time than the model simulation?
    • Is it possible to use point cloud information to populate elevations in Terrain Extractor (TRex)?
    • Is there a recommended level of Skelebration for different modeling conditions?
    • Junctions are created on top of one another after using ModelBuilder with the GIS-ID property
    • Learning Resource Guide for WaterSight
    • License usage in the ArcMap and ArcGIS Pro platform
    • LoadBuilder applying demands or loads to inactive elements
    • LoadBuilder importing zero flow loads
    • Log4net issues appear in security scans for OpenFlows products
    • Long time to load background layers
    • Manage Pump Speed Series
    • Manage Pump Time Series
    • Managing large number of scenarios
    • Missing Young's Modulus and Poisson's Ratio values in the material library
    • Modeling Arch section shapes in SewerGEMS
    • Modeling closed or pressurized pipes in PondPack
    • Modeling treatment for pollutants at nodes or ponds in SewerGEMS and CivilStorm
    • MrSid files are not available as a background layer type or an error is generated when loading MrSid files
    • +OpenFlows Academic Books
    • Pipe Renewal Planner Vs OpenFlows WaterCAP
    • Pipes connecting to the wrong element after submodel import
    • Pipes not merging when using Skelebrator with series pipe merging
    • PondPack error: Unable to open user roster
    • Problems opening GEOPAK Drainage file exported from StormCAD
    • Query, alert or formula UDX not working correctly with "=" (equals)
    • SCADAConnect in SewerGEMS
    • SCADAConnect Simulator in WaterCAD and WaterGEMS V8i SELECTseries 5
    • Series Pipe Merging in Skelebrator not working for pipes with zero diameter
    • Small difference in gutter worksheet result between US and SI units
    • The concentration at the stop node directly after a constituent source in a tank is decreasing rapidly
    • The control symbol, check valve symbol, and dashed lines connecting customer meters, isolation valves, and SCADA elements are not visible in the ArcMap or ArcGIS Pro platforms
    • The headloss in a pipe downstream of a parallel VSP is higher than expected
    • The result field "Depth (Flooding)" is listed as N/A after computing a model with the SWMM engine. Is there a way to see the depth of flooding for a node?
    • Translated version still showing as English
    • Troubleshooting making a SCADA connection to Oracle database
    • Troubleshooting ModelBuilder issues and errors connecting to an Oracle database
    • User Data Extension not appearing in the Post-Calculation Processor's "Output Property" field
    • User Data Extensions in the Fireflow report
    • User Notification "More than one VSPB cannot control the same control node"
    • User notification when computing: IDF data is not supported by SWMM. Storm event is excluded from export.
    • User notification: "Conduit has a Stop control structure, but this is not supported next to the connected outfall element."
    • User notification: "Transition from CONCENTRATED to EXTENDED"
    • Using Imperial and Metric Hydro International Vortex Valves
    • Using US Survey feet
    • Warning about outlet hydrograph not cresting
    • WaterGEMS and WaterCAD Data Import FAQ
    • WaterSight - Pump Overview
    • What can I do to speed it up a file I need to extract elevations from is taking a long time to process in TRex?
    • What does Entrance Control mean?
    • What is the best way to model an orifice plate inside a catchbasin with surface storage above the catchbasin rim?
    • What is the difference between a stand pipe and an inlet box?
    • What is the purpose the Rainfall File, Runoff File, and RDII File in the Calculations Options?
    • What is the workflow for setting up pre and postdeveloped conditions for multiple return events?
    • What kind of demands should be used as the initial conditions of a transient simulation?
    • What's new in HAMMER V8i SELECTseries 6?
    • When running a query, why is it not picking up the elements that it should?
    • Why are there 2 entries for the same alternative in the dropdown menu in the properties of a scenario? One with an "i" and one without it.
    • Why are there so many extra element types listed for WaterGEMS and WaterCAD, such as surge tank, rupture disk, Periodic head-flow?
    • Why do I get a warning message about the rational method being used for the modified rational method?
    • Will SCADA Results Publishing work with only OPC sources?

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    Modeling a Connection to an Existing System

    Product(s): WaterGEMS, WaterCAD, SewerGEMS, SewerCAD
    Version(s): V8i, CONNECT Edition
    Area: Modeling
    Original Authors : Scott Kampa, Jesse Dringoli, Tom Walski


    Background

    If you are modeling only a portion of a larger system, you may have a need to model the hydraulics of the connection to that existing system. This can happen for example when modeling a proposed expansion (such as a new subdivision, industrial park, school, shopping mall, etc.). Frequently, the engineer will not have complete information on the system to which they are connecting, and must decide on an appropriate approach for modeling this connection.

    The most reliable method for representing the existing system is to include a least a skeletonized (simplified) representation of the significant system components that affect the project area. Typically, this representation would include tanks, pumps, control valves, and significant demands in the same pressure zone. This necessary information can usually be obtained through water utility mapping and modeling personnel.

    Another method for modeling a connection to an existing system is to represent the connection point as a constant head elevation using a reservoir element. This is a very simplified approach, and usually a very unreliable one, since it doesn’t account for any fluctuation in head due to changing system conditions (e.g., pump status, tank level) or demands.

    Note: see Sewer Applications if you are modeling a connection to an existing downstream sewer force main (pressure network).

    The reliability of the method described in this article lies somewhere between the two just described. It consists of representing the connection to the existing system as a reservoir and a fictitious pump with a 3-point characteristic curve based on static and residual pressure obtained during a two-hydrant flow test near the connection point. The fictitious pump will simulate the pressure drops and the available flow from the existing water system.

    Unlike the first approach described, this third method does not allow the engineer to capture the changes at the connection point due to, for instance, fluctuating tank levels and pump status changes in the supply system. However, it does allow for consideration of change in head due to variation in the demand at the connection point. When combined with a good general understanding of how the larger system performs under a range of conditions and knowledge of system conditions (e.g., tank and pump status) at the time flow tests were performed, it can be an acceptable approach in many instances. It is usually most appropriate for “fill in” development where most of the customers and infrastructure are already in place as opposed to large expanses of undeveloped land at the fringe of an existing system. If model results obtained using this method are near the borderline of being unacceptable, the engineer should revert to the more rigorous first approach.

    NOTE: This method is only an approximation, so the results will not be as accurate as if you modeled the system back the actual source. It is also important to note that you cannot model multiple connections to an existing system. The results in such a case could be skewed and will not be viable.

    In order to simulate the range of pressures at the connection point for a range of flows, you must first obtain two-hydrant flow test data. To represent zero flow, you'll need the static pressure. To represent the highest flow possible through the connection, you'll need the residual pressure and flow. To convert the pressures to hydraulic grade, you will need to know the exact elevation of the residual pressure gage. This data is obtained from field tests.

    For more information on how to perform a field hydrant test, you may refer to section 5.2 of Advanced Water Distribution Modeling and Management.

    NOTE: The flows you obtain from the hydrant test must be in actual flow units such as gallons per minute, not pitot gage pressures. Equation 5.1 in Advanced Water Distribution Modeling and Management provides a conversion.

    Steps to Accomplish

    The reservoir element simulates the supply of water from the existing system. The Elevation of the reservoir should be equal to or slightly higher than the elevation at the connection point as explained in this article. The pump and the pump curve will simulate the pressure drops and the available flow from the existing water system. The points for the pump curve are generated using a mathematical formula (given below), and data from a hydrant flow test. The pipe between the fictitious reservoir and pump should be smooth, short and wide so as not to contribute headloss. For example, a Roughness of 140, length of 1 foot, and diameter of 48 inches are appropriate numbers. Please note that it is ALWAYS best to model the entire system back to the source as mentioned further above. The reservoir+pump method is only an approximation, and may not properly represent the water system under all flow conditions.

    Qr = Qf * [(Hr/Hf)^.54]

    where:

    Qr = Flow available at the desired fire flow residual pressure
    Qf = Flow during test
    Hr = Pressure drop to desired residual pressure (Static Pressure minus Chosen Design Pressure)
    Hf = Pressure drop during fire flow test (Static Pressure minus Residual Pressure)

    Determining the Three-Point Pump Curve

    Below is an example of how the three-point pump curve is developed. This will use the flow test results from your system, but the steps below will be same once you have that data.

    1. The first point is generated by measuring the static pressure at the hydrant when the flow (Q) is equal to zero.

    Q = 0 gpm
    H = 90psi or 207.9 feet of head (90 * 2.31)

    (2.31 is the conversion factor used to convert psi to feet of head).

    2. The engineer chooses a pressure for the second point, and the flow is calculated using the Formula below. The value for Q should lie somewhere between the data collected from the test.

    Q = ?
    H = 55 psi or 127.05 feet (55 * 2.31) (chosen value)

    Formula:

    Qr = Qf * (Hr/Hf)^.54
    Qr = 800 * [((90 - 55) / (90 - 22))^.54]
    Qr = 800 * [(35 / 68)^.54]
    Qr = 800 * [.514^.54]
    Qr = 800 * .69
    Qr = 558

    Therefore, Q = 558 gpm

    3. The third point is generated by measuring the flow (Q) and the residual pressure of the hydrant.

    Q = 800 gpm
    H = 22 psi or 50.82 ft. of head (22 * 2.31)

    Pump curve values for this example:

    Head (ft.)        Discharge (gpm)

    207.9                0
    127.05              558
    50.82                800

    Setting up the Model

    To set up the model, you will enter the pump curve just developed, lay out the model elements, and enter their attributes within your project area.

    1. Open your model in WaterCAD/WaterGEMS (or open the existing model if you have already laid out the elements for the new system) and go to Components > Pump Definitions.

    2. In the Pump Definitions Manager, click the "New" button and name your pump definition appropriately (such as "Connection").

    3. Keep the default Pump Definition Type of "Standard (3 point)" and enter your data in the table:

    4. Click the "Close" button to accept the curve, which we will use further below.

    5. Now lay out the elements in the model (if this is not already done). You will need a reservoir and pump, which represents the connection to an existing system.

    6. To adjust the attributes of these elements, first open the properties of the reservoir node and set the "Elevation" attribute to the elevation of the pressure gauge used at the hydrant, since this is the point from which the hydrant pressures (the source of the fictitious pump curve) were measured. To explain further: the head points on the fictitious pump curve are calculated based on the pressure as measured from the hydrant elevation. They represent the head available at the connection point, above the reference point where the pressure was measured from (elevation of the pressure gauge at the hydrant). In order for the fictitious pump to produce the correct pressure/hydraulic grade in the downstream new system, it needs to add those heads to the hydrant elevation. This is why you enter the pressure gauge/hydrant elevation as the elevation of the upstream reservoir element, since a reservoir acts as a boundary hydraulic grade; it sets the hydraulic grade and then the pump adds head to it to achieve the downstream pressure.

    Note that the pipe connecting the reservoir to the pump which be such that the hydraulic impact is negligible. For example, a Roughness of 140, length of 1 foot, and diameter of 48 inches are appropriate values.

    7. Open the properties of the junction element immediately downstream of the pump. This point represents where the proposed system begins, so enter the physical elevation of the connection point.

    8. Open the properties of the pump element and select the pump definition you created in step 3 from the "Pump Definition" dropdown. Set the "elevation" slightly below the elevation of the reservoir (slightly below the elevation of the pressure gauge, where the pressure was measured from). The elevation of the pump is of little importance since it just determines the calculated pressure as reported from the pump itself and does not influence the downstream pressure (since the pump is adding head to the upstream boundary condition to achieve the downstream pressure). However if you simply set the pump elevation equal to the reservoir elevation, any slight headloss in the pipe between the pump and the reservoir will result in a hydraulic grade slightly below the pump elevation and you'll see a user notification about negative pressure. So by setting the elevation slightly below the reservoir elevation, you'll avoid the negative pressure notifications. 

    9. Make sure the rest of the system is set of correctly and compute the model. The pump should react according to the proposed system demands to provide an approximation of head at the connection point.

    Assumptions and Limitations

    This approach is an approximation, the accuracy of which depends on a number of factors.

    It is better to model all the way back to the source, at least by obtaining skeletonized data on the existing system. The skeletal model must begin at the real water source(s), such as the pump or tank, which will serve as the primary water source(s) for the new extension pipes. It should be calibrated using the results of fire hydrant flow tests, especially the tests conducted near the location where the new extension will tie in. You may need to call the municipality to obtain basic information on the existing system.

    Using the pump approximation method can present problems because this approximation of the existing system only accounts for the exact boundary conditions and demands that existed at the time that the test was run (for example, the afternoon on an average day with one pump on at the source). Basically, the simulated connection is only valid for the conditions present during the hydrant tests. Therefore, determining the effect of changing any of the demands or boundary conditions is difficult. An extended period simulation (EPS) that is performed using the pump approximation method will be less accurate and may not provide reliable data regarding projected changes in consumption. The pump approximation approach only works well if the existing system is fairly built-out near the connection point and the demand and operation conditions are expected to remain essentially the same in the long run. The hydrant flow test is useful for predicting changes in pressure when downstream demands change, but not for evaluating other types of system changes such as the addition of new pipes, or operational alternatives such as fire pumps starting up.

    Modeling more than one connection between the proposed expansion and the existing system may not be a valid approach.

    Some reasons for this are, first, the hydrant tests were most likely done at different times, yet the model will allow water to be taken from both sources at the same time. This is not accurate because in reality, both sources will not be able to provide the full observed residual pressure when open at the same time. In other words, if hydrants or connections were really opened at both connection points simultaneously, the combined flow would result in a much reduced residual pressure at both locations versus what was observed during the independent tests. Secondly, in some cases, depending on the hydraulic grades, it may be possible for flow to enter at one connection point and exit at another. However, the pump element only allows water in the forward direction, so the pump approximation method would not work in this case (and may provide a message about one of the pumps not being able to deliver head). The situation is too complex to model using a method other that a skeletonized representation of the larger system.

    However, if you are modeling a system where the upstream system will not experience a significant change in pressure as a result of multiple connections flowing at the same time, or if there are separate, disconnected systems upstream of each connection point, modeling multiple connection point may be fine.

    As the size of the modeled system increases and the number of connection points increases, it may not be reasonable to separate the development site from the rest of the system and achieve accurate results. The interactions may be too complex. One suggestion in this case is to get together with the City water distribution engineers and discuss how to model this. Ideally you would get a copy of the City model (at least the pressure zone of interest) and build your model on top of it. Or you can get their distribution maps and build very simple skeletal model of the system. You need to model back to some real boundary condition.

    One, somewhat far fetched, test might be to run (assuming you have 6 connection points) 6 simultaneous flow tests. You couldn't run all the hydrants wide open (unless you have a very strong system) without lowering the pressure too much. So, if your demand is 1800 gpm for example, you could run 300 gpm at each flowed hydrant. This isn't as good as running a model of the full pressure zone but at least it gives you an idea of what a 1800 gpm demand will do to the City system.

     

    Attempting to compute the 'static' (no demand) conditions of the new model with the pump approximation in place will most likely result in an unbalanced simulation.

    In this case, you may need to model the connection simply as a reservoir with an elevation equal to the pressure gauge elevation and static pressure head (i.e., the static HGL), or simply manually compute the static pressure at each node by taking the difference between the static HGL and the node physical elevation.

    Sewer Applications

    For a sewer force main (pressure sewer system) in SewerGEMS or SewerCAD, you may have a need to model a pump for a specific area and do not have the full downstream model. In this case you will need to approximate the hydraulics of the connection point (manifold) to the downstream system. This can be done using an outfall node element (for SewerCAD and SewerGEMS, or a reservoir if modeling this in WaterCAD or WaterGEMS) to establish the boundary hydraulic grade that the upstream pump will be pumping against. Set the elevation of the outfall to the pipe elevation, set the bounndary type to user defined tailwater, and set the user defined tailwater equal to the hydraulic grade in the existing force main (pressure head plus elevation). Or if using WaterCAD or WaterGEMS to model this, set the reservoir elevation to the hydraulic grade that you will be assuming at the connection point.

    However, the elevation that you choose will not always be accurate for all times. The pressure that you are tying into may depend on how many other pumps are running in the un-modeled system, and will also be influenced by the additional flow that you are adding to that system. Meaning, you may measure a pressure of 50 psi for example at the connection point right now, but when your pump is tying in and adding additional flow, that increases the downstream headloss, which will cause the pumps in the existing system to add more head, which will increase the pressure at the connection point. You could use a rating curve as the outfall boundary type, but the rating curve would need to be determined.

    As seen further above, in a water distribution system application hydrant flow tests can be used to determine how the pressure changes as the flow changes, but in a sewer application you likely cannot simply inject a range of flow near the tie-in point to determine this (and then model it as an outfall with elevation-flow rating table). So, a conservative assumption may need to be made for the tie-in pressure (outfall elevation), perhaps based on any data that you happen to know about the system. Ideally you would be able to access a hydraulic model of the entire system, or at least a skeletonized version.

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