Product(s): WaterCAD, WaterGEMS Version(s): 10.00.00.50 Area: Calculations Problem I've entered a minor loss coefficient for an isolation valve but the calculated minor loss in the associated pipe is zero. Solution As of version 10.00.00.50, headloss resulting from a minor loss coefficient on an isolation valve is included in the "Headloss (Friction)" result field in the associated pipe. This is noted in the Description field seen at the bottom of the Property Grid when selecting the "Headloss (Minor)" or "Headloss (Friction)" property of a pipe. See Also How does the diameter of an isolation valve effect the calculated results?
↧
Wiki Page: Minor losses for Isolation Valves
↧
Wiki Page: How does the diameter of an isolation valve effect the calculated results?
Applies To Product(s): WaterCAD, WaterGEMS Version(s): 08.09.400.34+ Area: Calculations Original Author: Jesse Dringoli, Bentley Technical Support Group Problem How does the diameter of an isolation valve effect the calculated results of a WaterCAD / WaterGEMS model? Problem Number: 33406 Solution The diameter is used to determine the velocity through the valve. If no minor loss coefficient is entered for the isolation valve, the only effect this will have would be the reported velocity at the valve location (reported in the isolation valve properties.) However, if you enter a minor loss coefficient (which you should) the diameter will effect the headloss through the valve. This is because the headloss equation considers velocity and as the diameter decreases, the velocity increases. See Also Minor losses for Isolation Valves
↧
↧
Forum Post: RE: Comparison hydrographs- Civil Storm and another two models (using SCS method)
Thanks Jesse.. The answers for your points as follow. Civil Storm and Infoworks simulation starts at 00:00 time whereas HEC HMS simulation starts at 7:00. That is why we can see time difference for the peaks. Anyway for all the cases we use 10min time of concentration (small catchment). 1. yes I built the full models with Civil storm and infoworks, but comparison has been done for a particular catchment. 2. SCS unit hydrograph method was used for all the cases. 3. Yes correct Storm has been used (5 year storm) 4. I didn't try this method. Anyway I will try. 5. Model with that specific catchment is attached (Bentley Secure File Upload). Thanks
↧
Wiki Page: How do you save backup files, so they save at different times and multiple levels?
Applies To Product(s): WaterGEMS, SewerGEMS CivilStorm, StormCAD, PondPack, SewerCAD, HAMMER, WaterCAD Version(s): 08.11.XX.XX, 10.00.XX Original Author: Mark Pachlhofer, Bentley Technical Support Group Problem How do you save backup files, so they save at different times and multiple levels? Solution 1) In the CONNECT Edition software go to Tools > Options (the arrow in the lower right corner of the tools section. See screen shot below) or use the Search bar. In the V8i versions go to Tools > Options. 2) Set the backup levels to something other than the default level, which is 1, and click the "Ok" button. With each backup level added a new copy of the project will be saved every time the model file is saved. See Also Can I restore a backup file of my model project?
↧
Wiki Page: Percentage full & volume in constant area tank both report 0 for an EPS run, but the tank level (calculated) is shown to be greater than 0.
Applies To Product(s): WaterGEMS, HAMMER, WaterCAD Version(s): 08.11.XX.XX Original Author: Mark Pachlhofer, Bentley Technical Support Group Problem The percentage full and volume in a tank are both showing as 0 at the beginning and end of my EPS simulation, but the tank elevation or level (calculated) is shown to be greater than 0. Solution Check to see if your tank is set to a variable area tank. If it is change the tank type to a constant area and with an equivalent diameter.
↧
↧
Wiki Page: How can I find the total volume from a hydrograph?
Applies To Product(s): Bentley SewerGEMS, Bentley CivilStorm, Bentley PondPack, Bentley SewerCAD Version(s): 08.11.XX.XX Original Author: Mark Pachlhofer, Bentley Technical Support Group Problem How can I find the total volume from a hydrograph? Solution In the storm and sewer products there is no totalzing flow meter like in the water products, so you have to use the method below: *This example find the total volume of flow in gallons per minute. 1) Go to Analysis > Calculation Options and double click on the calculation option that has the red check mark on it. Change the output increment to 1 minute, so it generates 1 minute time steps. If you're using cfs as your flow unit change the output increment to seconds. 2) Right click on the catchment area or pond and choose "data table". Scroll down to hour 11 then left click and hold to drag your cursor down the column to highlight the flows for the time step you're analyzing. Press CTRL + C to copy the information to the clip board and paste it to Excel. Use the sum function to add up the flows. 3) Take the sum and divide by 60 to get the total volume for that time period. See Also
↧
Wiki Page: Show properties for multiple elements type (eg. manholes and conduits) in a single flextable
Applies To Product(s): SewerGEMS, CivilStorm, StormCAD, SewerCAD Version(s): 08.11.XX.XX Original Author: Mark Pachlhofer, Bentley Technical Support Group Problem Can I display properties for multiple elements types in a single flextable for the Haestad Storm and Sewer products? Solution Yes ,to get multiple element types to show in a single flextable using the table called the Network Elements flextable, which contains all the elements in the entire model file. In some products, you may need to add a new project or shared Flextable and choose the Network Elements type: To show only one or two of those element types create a selection set of elements and open the flextable based on that selection set. There are multiple ways to create a selection set, two of which are described in this wiki . After creating the selection set open the flextable based on the selection set using the steps described in option 2 here . The final step would be to customize the flextable to show the columns you need reporting for. See Also Create a selection set Filter a flextable based on a selection set or query
↧
Wiki Page: Troubleshooting unstable SewerGEMS and CivilStorm results using the implicit solver
Applies To Product(s): SewerGEMS, CivilStorm Version(s): 08.11.XX.XX, 10.XX.XX.XX Area: Modeling Original Author: Mark Pachlhofer, Bentley Technical Support Group Problem How do you troubleshoot SewerGEMS or CivilStorm results using the implicit solver? Solution If your hydraulic model provides unexpected results or high continuity error (mass balance), try the following steps: 1. Check the model for data entry problems: Use the Validate command and look at the warnings and/or errors that are reported. Fix as many as you can while keeping in mind the goal of the model is to make it resemble what you have in the field as closely as possible. When you Calculate the model, validation routines are performed that are not included during a Validate operation. Review the warnings and/or errors that are returned after calculating the model too. Examine Graphs and Profiles. Create Flow plots at splits and at pump discharge areas and look for jagged peaks in the plot. Common data problems: Conduits or Channels: I ncorrect channel or conduit slopes : Reasonable slopes are generally small and rarely negative. You can view slopes along a reach visually by using the Profiles feature. You can find unusually large or negative slopes through User Notifications and FlexTable reports. You can Color Code link elements by Slope and look for excessive values. If the model has parallel conduits connected by a flat (slope value of 0) conduit, try making that conduit Inactive. I nc orrect Channel or Conduit size : Look for unusual size changes along a reach. Color code drawing by Diameter to look for this type of discrepancy and or create numerous profiles for an even better visual of your pipe sizes. This will help you locate bottlenecks in the system that could be causing calculation problems. You will also see user notifications if the diameter decreases as you move downstream. A mix of very long and very small pipes . Eliminate or combine short pipes because their effect on routing is small. Break exceptionally long pipes into mutliple pipes that are each roughly the same length as other pipes in the network. Very low flows : If flows are less than 0.01 cfs (0.001 m3/s), depths may fall below accuracy tolerances. Consider omitting dry pipes from the model (or combine/skeletonize them out) Pumps and pressure pipes: Pumps operating at or near the shutoff point defined on the pump curve When pumps operate at or near the shutoff head point on their curve review downstream results for accuracy. In the past there have been cases where graphs of the hydraulic grade would show large jumps that were out of the range of the normal pump operating points. To resolve this adjust the pump curve by reducing the flow or head accordingly to produce a curve that operates near the point the pump is running at in the model. The new pump curve can be tested using the SewerCAD (GVF-Convex solver) because the pump calculations are done using the pressure solver, which is more stable for pump calculations than the implicit solver. Pumps using a multiple point pump curves that have large differences between flow or head values on the pump curve. Pumps that cycle on and off very quickly - check the on/off elevations and wetwell size/operating range. Make sure the pump curve is sized appropriately for the wetwell size. Use a small calculation timestep if fast pump cycling is needed. Manifolded pumps (pressure pipes combining together). This may require a small calculation timestep. The Implicit solver tends to be better than the Explicit (SWMM) solver with this. Unnecessary check valves on pressure pipes. Users commonly use the option to have a check valve on pressure pipes that are directly downstream of a pump, but this is unnecessary because pumps already have built in check valves. Keeping them can cause unnecessary difficulty for the solver. Parallel pumps - the short pipes adjacent to the pump may need to be designated as Virtual. Try toggling the "is virtual?" setting. Ponds and pond outlet structure s: Flow control structures on relatively small storage nodes (ponds, wet-wells). Consider combining ponds, modeling as manhole storage or using a very small calculation timestep. Unusually small ponds compared to their inflow. Consider modeling as a manhole with downstream conduit start control structure, or use a very small calculation timestep. Significant backwater/tailwater effects against an upstream pond outlet structure. If a backup occurs and acts as tailwater for an upstream pond outlet, this can be extremely challenging to solve. A very small calculation timestep may be necessary, the Explicit (SWMM) solver may need to be used (with a very small Routing Step). Or, consider changing the model layout or otherwise resolving the downstream backup to prevent this challenging situation. Conduit control structures : Using a start control structure tends to be more stable than a stop control structure Use a smaller calculation timestep in cases where a large change in flow can occur with a small change in head, such as when using a weir. Significant backwater/tailwater effect against a conduit control structure can be challenging to solve. A very small calculation timestep may be necessary, the Explicit (SWMM) solver may need to be used (with a very small Routing Step). Consider using an approximate pond (representing the ponded area upstream of the control) with pond outlet structure, which might work better in some situations Storm Data: Make sure the storm data entered has labels and the data entered is correct. Verify data input in the following other challenging situations Flow splits at weirs and orifices that are dry at certain points during an extended period simulation. Hydrograph rapidly changes within a short time (minutes). Very sharp flood waves - check catchment runoff hydrographs to make sure they are correct. Near-critical slopes. Significant and abrupt changes in the conduit size, shape and/or slope. Looped networks. Significant backwater conditions. System inflows vastly exceeding the system capacity resulting in mass flooding. 2. Simplify where possible Dynamic solvers tend to be complex, and little changes can sometimes make a big difference. What you should keep in mind when creating a dynamic model is to keep things as simple as possible and only model what you really need to study. In other words, if there are some conduits that can be left out because they won't have a significant effect on what you are studying or don't provide a lot of flow (near-dry) don't put them in the model or take the flow they would produce and add it to another node element as an inflow. With dynamic modeling less is better than more. If you're working with a very large model, you may have a much easier time splitting it into smaller subsections if possible. Then, work on the sections one by one. Trying to troubleshoot results in a very large model can be cumbersome and overwhelming. Examples 1) Parallel conduits with the exact same physical properties . Instead of putting both conduits in the model you might model this as one conduit with 2 barrels. 2) A pond with an outlet structure. Let's say the outlet structure was made up of a 24 inch orifice and a weir at the very berm of the pond. After going through the outlet structure the water goes into a 24 inch conduit. Assuming the water never gets up to the level of the weir what you could do to simply this situation is set the Pond Outlet Structure property for "Has control structure?" = 'No'. In this situation, this can be done because the conduit was the same size as the orifice, so the conduit will act as the controlling structure for incoming water. 3) A wet well with a sanitary load. Remove the sanitary load that is directly on the wet well and add it to a manhole upstream of the wet well or create a dummy manhole directly upstream and connect it to the wet well. Before: After: 3. Adjust the calculation options to reduce the continuity error Default values for calculation options will work for the majority of cases, but some systems need small adjustments to converge. When the calculation is moving very slowly (you can observe that the model is stuck at certain times) or the results show apparent instabilities, it is an indication that the model is experiencing difficulties in converging to a stable and robust result. Try adjusting calc options in the order below. This is an iterative process and only one option should be adjusted at a time to see whether it gives better results or worse results. If the choice provides better results see if you can adjust it again more in the same direction to provide even better results than the first choice. For example, if changing the computational distance at 50 ft provides a continuity error of 25% and adjusting to 10 feet provides a continuity error or 15% then try to adjust it further to 5 feet to see if you can reduce the continuity even more. The goal with this is to get the continuity for the model under 5% and the lower the error the more accurate your results. Initial conditions: Options include warm start or transitional start. Try both and see if one gives better results for your system. Calculation Option Suggested Range of Values Computational Distance 5 ft - 75 ft Calculation Time Step 0.005 hr - 0.025 hr NR Weighting Coefficient 0.7 - 0.990 Relaxation Weighting Coefficient 0.6 - 0.990 NR Iterations 5 - 20 LPI Coefficient 1.0 - 15.0 Most of the time you can get the continuity error under 5% using the 4 options above. If you still need to adjust things after that continue in the order below. Try an NR Weighting Coefficient value of between 0.9 and 0.99 with the default Computational Distance and Calculation Time Step. Set NR back to default and try reducing the Computational Distance value. Set Computational Distance back to default and try reducing the Calculation Time Step value. Keep the Calculation Time Step the same and repeat the above steps. Try increasing the the NR Iterations to 20. Try increasing the LPI Coefficient to a value over 5.0. You do not need to go higher than 15. Note: There is no absolute rule on whether the time step, LPI Coefficient, or the NR weighting coefficient should be changed or to what specific value; normally you should reduce the time step and increase the NR coefficient but sometimes the opposite can also help. 4. Isolate problems areas: Isolate the problem area by incrementally deleting small sections of your model and re-computing. This may help you narrow down the source data that the engine has trouble with. It may expose data entry issues or areas that are exhibiting common modeling difficulties. 5. Determine at what time step the problem occurs. Look for what is happening at that time. Is a weir beginning to overflow? Is it the first time a large pump comes on? Sometimes it's easiest to look at your user notifications for the time or locate the problem on a profile and slide the time browser bar to that location before examining the model. 6. Switch to using the Explicit (SWMM) numerical solver (Analysis > Calculation Options > Click on the active option to open the properties). If there are problems when using the SWMM engine, try changing the Routing Method from Dynamic Wave (default) to Kinematic Wave or Uniform Flow. These methods do not handle backups as accurately as dynamic wave, but they tend to be more stable. If the results are still not stable with the SWMM solver (as seen in the summary output text report), try reducing the Routing Time Step calculation option. Suggested value range: 1.0 sec - 30 sec. Smaller values tend to yield more stable results. Note: Headlosses at nodes are ignored during periods of supercritical flow. Troubleshooting unstable SewerGEMS and CivilStorm model results using the Explicit SWMM Solver See Also
↧
Wiki Page: What is the continuity error and what's a good percentage for it?
Applies To Product(s): SewerGEMS, CivilStorm Version(s): 10.00.xx.xx, 08.11.xx.xx Area: Help and Documentation Original Author: Mark Pachlhofer, Bentley Technical Support Group Problem Description What is the continuity error and what's a good percentage for it? Solution The continuity error is the total system computational continuity balance error which accounts for total inflows into the system, outflows, flow losses due to overflows, and volume changes. It's really a measure of how hydraulically stable your results are. Typically, anything under 5% continuity error is usually acceptable, but it really depends on the agency that is reviewing your model and what type of values that you need your model to adhere to. Obviously, the lower you can get your continuity error in any SewerGEMS model the more stable the model should be, but in order to really know if the results you are getting are good you should compare it to your system results in the field. Mathmatically, the continuity error is a discrepancy in mass balance, expressed in percent (or ratio if you change the units to unitless.) Continuity Error = |(Ti - To - Tf - Td)/Ti| Ti = Total Inflow Volume To = Total Outflow Volume Tf = Total Overflow volume Td = Total Volume Change For example, if the total inflow volume is 1000 gallons, total outflow is 700 gallons, total overflow is 100 gallons and total volume change is 100 gallons, the continuity error is: |(1000 - 700 - 100 - 100) / 1000| = 0.1 or 10% Basically the total inflow is 10% greater than the total outflow+overflow+change. This mass balance error is typically due to instability in the model calculations, which could be due to problems with data input or a hydraulically challenging model. In the latter case, you may need to adjust advanced calculation options to achieve better continuity error. Note that if the total outflow volume is greater than the total inflow volume, this equation is used instead: Continuity Error = |(Ti - To - Tf - Td)/To| You may also want to have a look at the help document titled "Troubleshooting DynamicWave Model Calculations" for some of the issues that can cause changes in continuity error and how to adjust the calculation options in an iterative process in order to stabilize your results. You can also find the continuity error on a per-element basis using the Hydraulic Reviewer tool . This can help pinpoint the location of issues or challenging model arrangements. See Also Troubleshooting unstable SewerGEMS and CivilStorm results using the Implicit solver How to find volume (such as overflow volume) through specific elements Using the Hydraulic Reviewer to Check Per-Element Volume and Mass Balance
↧
↧
Wiki Page: How to register DAO360.dll or a dll file
Applies To Product(s): Bentley WaterGEMS, Bentley WaterCAD, Bentley HAMMER, Bentley SewerGEMS, Bentley SewerCAD, Bentley StormCAD, Bentley CivilStorm, Bentley FlowMaster, Bentley PondPack, Bentley CulvertMaster Version(s): 08.11.xx.xx Area: Modeling Original Author: Bentley Technical Support Group The steps below will help to register the DAO360.dll file. This is sometimes needed in cases where an error is encountered when opening a Hydraulics & Hydrology product or model file, with the details of the error mentioning "engineeringlibraries". Solution Method 1 The following command can be run from a command line window or Start Menu > Run window. It is important to use correct punctuation and capitalization. After typing it in press enter. OR: In a 32 bit machine: regsvr32 "C:\ Program Files\ Common Files\Microsoft Shared\DAO\DAO360.dll" In a 64 bit machine: regsvr32 "C:\ Program Files (x86) \Common Files\Microsoft Shared\DAO\DAO360.dll" After typing the above command, press Enter and a message similar to the following will be displayed: Method 2 Browse to the dao360.dll file. (Windows XP) C:\Program Files\Common Files\Microsoft Shared\DAO\ (Windows 7) C:\Program Files (x86)\Common Files\Microsoft Shared\DAO\ Right click, choose to "open with", then browse out to and open it with the regsvr32.exe file, typically located in C:\Windows\System32\. Now try opening the program and see if the issue is resolved. Other Options If you still get the error, try the steps in this article .
↧
Wiki Page: Error when opening: "System.TypeInitializationException"
Applies To Product(s): SewerGEMS, SewerCAD, StormCAD, CivilStorm, WaterGEMS, WaterCAD, HAMMER, PondPack Version(s): 08.11.03.83 and 08.11.03.77 (for Storm and Sewer products); build 08.11.03.19, 08.11.03.17, and 08.11.03.16 (for Water products) Area: Installation Original Author: Scott Kampa, Bentley Technical Support Group Error Messages "System.TypeInitializationException" When opening the program: System.TypeInitializationException: The type initializer for 'Haestad.Domain.LibraryObjects.EngineeringLibraryService' threw an exception. Haestad.Domain.DaoInterop.DAOException (0x80040154): COMerror not documented at Haestad.Domain.DaoInterop.InteropLibrary.ThrowCOMException(_com_error* e) at Haestad.Domain.DaoInterop.DaoDatabase.CreateDatabase(String fileName, CultureInfo locale) at Haestad.Domain.LibraryObjects.JetAppSettings.OpenRegistryDatabase(String fileName) at Haestad.Domain.LibraryObjects.JetAppSettings..ctor(String filename) at Haestad.Domain.LibraryObjects.EngineeringLibraryService.OpenImpl() at Haestad.Domain.LibraryObjects.EngineeringLibraryService..cctor() When opening a file: System.TypeInitializationException: The type initializer for 'Haestad.Domain.LibraryObjects.EngineeringLibraryService' threw an exception. at Haestad.Domain.LibraryObjects.EngineeringLibraryService.set_ProjectWiseManager(ProjectWiseManager value) at Haestad.Framework.Application.ProjectManagerBase.get_ProjectWiseManager() at Haestad.Framework.Application.ProjectManagerBase.get_IsProjectWiseAvailable() at Haestad.Framework.Application.HaestadParentFormModel.get_IsProjectWiseAvailable() at Haestad.Drawing.Control.Application.GraphicalParentFormUIModelBase.Initialize() at Haestad.Drawing.Control.Forms.GraphicalDrawingParentForm.DoLazyInitialization(Boolean lazyInitialize) at Haestad.Drawing.Control.Forms.GraphicalDrawingParentForm.FileNew() at Haestad.Montana.Forms.MontanaXMParentForm.FileNew() at Haestad.Framework.Windows.Forms.Forms.WelcomeForm.buttonCreateNewProject_Click(Object sender, EventArgs e) at System.Windows.Forms.Control.OnClick(EventArgs e) at System.Windows.Forms.Button.OnClick(EventArgs e) at System.Windows.Forms.Button.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) How to Avoid Option 1: Register the DAO File The error could be occurring because of unregistered DAO. See this article for steps to register the DAO360.dll file. Option 2: Upgrade to the latest version of the program You can find the steps to upgrade to the latest version here . Option 3: Delete Engineering Libraries [[How to Delete Engineering Libraries|Delete the engineering libraries]] See Also How do I download the Water and Storm-Sewer hydraulics and hydrology products? How to register DAO360.dll or a dll file How to Delete Engineering Libraries
↧
Wiki Page: How can I direct the bypass flow?
Applies To Product(s): CivilStorm, SewerGEMS Version(s): 08.11.XX.XX Area: Layout and Data Input Original Author: Terry Foster, Bentley Technical Support Group Problem How can I direct the bypass flow? Problem ID#: 55632 Solution Lay out a second conduit and it will handle the diversion automatically. You would have multiple pipes leaving the manhole. You can put a start control structure on either of the downstream pipes if you want it to use the orifice equation or a rating curve.
↧
Wiki Page: Why is the "Bypass Target" field disabled for my catchbasins, even though bypass flows were calculated?
Applies To Product(s): StormCAD, SewerGEMS, CivilStorm Version(s): 08.XX.XX.XX Area: Modeling Original Author: Jesse Dringoli, Bentley Technical Support Group Problem Why is the "Bypass Target" field disabled for my catchbasins, even though bypass flows were calculated? How do you specify the bypass target for an inlet / catchbasin in StormCAD V8 XM and V8i? Problem ID#: 42289 Solution The bypass target is specified by drawing a gutter between the inlet and the next downstream element. For example, look at the Sample_2.stc file that is included with StormCAD, under C:\Program Files\Bentley\StormCAD8\. On the upper right side of the model, notice how there is a gutter link going from catchbasin A02-1 to B02-1. This tells the program where the bypass flow goes. Once you compute the model, the "bypass target" field in the catchbasin properties will update. In the help documentation, this is mentioned under Contents > Creating Models > Elements and Element Attributes > Link Elements. If the gutter element is omitted, then StormCAD does not know where the bypass flow was supposed to go, and therefore sends the bypass flow directly to the outfall. You will get a user notification telling you about this when it happens. See Also How can I direct the bypass flow?
↧
↧
Wiki Page: How is Initial Abstraction considered with the SCS Unit Hydrograph method?
Applies To Product(s): PondPack, SewerGEMS, CivilStorm Version(s): V8i, CONNECT Edition Environment: N\A Area: Calculations Original Author: Dan Iannicelli, Bentley Technical Support Group Problem Is the Initial Abstraction taken into account regarding the Storm Rainfall Depth versus the Runoff Depth? Problem ID#: 69525 Solution Initial Abstraction is a parameter that accounts for all losses prior to runoff and consists mainly of interception, infiltration, evaporation, and surface depression storage. In theory all Rainfall minus Initial Abstraction will generate the runoff from a specified Catchment. The formula for Initial Abstraction is utilized in the SCS method. The formula is: Ia = 0.2S where S = (1000/CN)-10 and P = Precipitation (in) In PondPack, to visualize the Initial Abstraction leaving the storm rainfall total you can use the following steps. You can compare the storm rainfall with the water runoff by viewing the Runoff Hydrograph - Unit Hydrograph Summary in the reports section of PondPack. In this Unit Hydrograph Summary report you will see Depth of the Storm Event (in.) This is the initial rainfall value. Now to find the Runoff volume (in), you can utilize the following equation. Q = ((P-0.2S)^2) / (P+0.8S) Where Q= Total Runoff volume (in) P = Total Precipitation (in) S = Potential maximum retention (in) after runoff. As you can see, the Initial Abstraction is taken into account in this Runoff formula. So the calculations take the Initial Depth of the Storm Event and calculate the Cumulative Runoff Depth which is also in the Unit Hydrograph summary report. See Also Catchment's total runoff and peak flow are different than HEC-HMS
↧
Wiki Page: Is it possible to make a child alternative into a base alternative?
Product(s): WaterGEMS, WaterCAD, SewerGEMS, SewerCAD, StormCAD, CivilStorm, PondPack Version(s): 08.11.XX.XX Area: Modeling Problem Is it possible to make a child alternative into a base alternative? Problem ID#: 64157 Solution It is not possible to do this directly. However, it is possible to merge data from a child alternative into the alternative above it in the tree. This is done using the Merge icon in the Alternatives manager. To use this, select the child alternative, and select the Merge icon. You will get a message that says: "This action will move all records from 'child alternative' into 'base alternative' and remove 'child alternative'. Are you sure you want to merge 'child alternative'." This means that the data in the current child alternative will be applied to the alternative above it. Note that it is not possible to use the Merge function when if with alternative is being used by the current scenario. To merge the alternative change the scenario. You will also want to be very careful in removing alternatives because they may be used in other scenarios as well.
↧
Wiki Page: Lag Time versus Time of Concentration
Applies To Product(s): PondPack, SewerGEMS, CivilStorm Version(s): 08.11.XX.XX Area: Modeling Original Author: Dan Iannicelli, Bentley Technical Support Group The documentation mentions an "SCS Lag" with a built in factor of 0.6. Should I enter a lag time or a time of concentration for my catchments? Explanation Lag time = 0.6 * Tc The "SCS Lag" help topic is specific to the SCS Lag Tc method, not a general comment about the Tc (Time of Concentration). In general, the hydrology calculations in PondPack, SewerGEMS and CivilStorm always work with Tc, so if you're entering a user defined Tc, you would enter the Tc, not the lag time. The "SCS Lag" and other methods refer to the optional Tc calculators, which help you establish the total Tc if you don't already have it. Basically you click the ellipsis button next to the "Tc Data Collection" field in the properties of the catchment, then click the new button in the Tc Data Collection Dialog. You'll see numerous methods such as Eagleson, Carter, TR-55 sheet flow, SCS Lag, etc. These are standard methods established over the years for calculating the total Tc based on other known parameters. You'll see that when you select "SCS Lag", you must enter the hydraulic length, slope and CN. This tool will then use the equation mentioned in the help (which automatically applies a 0.6 factor) to compute the Tc, and then populates the Time of Concentration field for your catchment with that value, and uses it in the calculations. Again, if you already know the Tc, you would select "user defined" as the method, or select "user defined" as the "Tc input type" in the properties of the catchment. See Also How is Initial Abstraction considered with the SCS Unit Hydrograph method? SCS unit hydrograph method TR-20 or TR-55 Catchment's total runoff and peak flow are different than HEC-HMS
↧
Wiki Page: Catchment's total runoff and peak flow are different than HEC-HMS
Applies To Product(s): PondPack, CivilStorm, SewerGEMS Version(s): V8i, CONNECT Edition Area: Calculations Original Author: Mark Pachlhofer, Bentley Technical Support Group Problem The total runoff depth and peak flow are different between HEC-HMS and PondPack (or CivilStorm / SewerGEMS) when using the same settings for a SCS Unit hydrograph method catchment. Solution You should be able to get almost identical runoff from a single catchment/subbasin when comparing between PondPack/CivilStorm/SewerGEMS and HEC-HMS. Double check the data entry especially the units (e.g. HEC-HMS uses square miles as the area for catchments/basins while PondPack defaults to acres), since that is often a source of errors. In HEC-HMS your subbasin should have no canopy method, no surface method, and no baseflow method. Your loss method should be SCS Curve Number and your Transform Method should be SCS Unit Hydrograph. On the Loss tab be careful with setting an impervious area since that can change the effective curve number used in the calculations. If you do use a value greater than zero here make sure you do the same in PondPack / CivilStorm / SewerGEMS. Also, make sure that the "Initial Abstraction" in HEC-HMS is left blank (not zero), so that it is automatically calculated as 0.2 times the "potential retention", as that is what the SCS Unit Hydrograph method implementation in PondPack, CivilStorm and SewerGEMS will always do. Other differences to note are that HEC-HMS uses “lag time” whereas PondPack uses Time of Concentration. These are not the same thing. Lag time = 0.6 * Tc. HEC-HMS uses the HEC-1 unit hydrograph simulation method, whereas PondPack (by default) uses a hybrid approach of HEC-1 and TR-20. In order to match up the results in PondPack, go to Tools > Options > Project tab and change the Unit Hydrograph simulation option to “HEC-1 method”. HEC-HMS results seem to use an increment equal to the increment that the precipitation was entered, so it’s important to use that in PondPack/CivilStorm/SewerGEMS to get identical results. This could be important to note because sometimes the 'true peak' of the runoff hydrograph can occur between timesteps. For example if you use an output increment of 1 minute in PPK, you might get a peak that’s higher if it occurred between the 5 minute increments. This means that PondPack/CivilStorm/SewerGEMS provides more flexibility and accuracy in such cases. See Also SCS unit hydrograph method TR-20 or TR-55 Lag time Versus time of concentration How is Initial Abstraction considered with the SCS Unit Hydrograph method?
↧
↧
Forum Post: RE: Comparison hydrographs- Civil Storm and another two models (using SCS method)
Hi Dinusha, Thanks for including the additional information. The difference you're seeing is likely due to the Initial Abstraction. To achieve results comparable to CivilStorm, delete the value in the IA field in HEC-HMS so that it uses the same method as CivilStorm. I'm not sure where this is defined in Infoworks, but it may be in the "Unit Hydrograph Definition". See the below article from our wiki for more details: Catchment's total runoff and peak flow are different than HEC-HMS
↧
Haestad Calendar
Upcoming Training, Events and scheduled release dates for Bentley's Haestad products.
↧
Forum Post: CivilStorm model will not open after compacting database
I have a CivilStorm project which runs fine if I don't use the Compact Database feature. If I use the compact database tool, I get the message "ArgumentException:AddingDuplicate" and I can no longer open the model. I am running CivilStorm Select Series 5 (08.11.05.84 64bit). Any thoughts on what is creating this issue?
↧