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Simple Pond Routing of External Hydrograph 1

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RWF7437

Civil/Environmental
Dec 22, 2002
1,560
I have an external hydrograph. I don't know the drainage area, the rainfall or the CN....and don't care. I also have a pond which is 8 feet deep and contains 340,000 cf when full. It has an orifice ( 24-inch dia @El. 0.00) and a 20 foot wide by 2 foot hich broadcrested weir at El. 6.00. I have entered this data into a HydroCad model.

Is it possible to simply route this hydrograph through this pond ? I have created a text file called LACOEX.hce but can find no way to "import" it into my model?

This is ( for me ) a very common problem and I need to find a simple way to do this simple task. I can do it using SMADA but it seems obscure in HydroCad. SMADA also has some "bugs" which yield incorrect results.
 
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! Based on HydroCAD sample external hydrograph file LinkTest.hce
! File format Copyright (c) 2004 HydroCAD Software Solutions LLC
!
! Note: This sample file will be updated whenever a HydroCAD update is installed!
! If you want to customize this file, make a copy under a new file name.
! Saved as LACoEX.hce
! The following items are recognized in this file:
! FileUnits - English or Metric
! Comment - To appear in reports
! [hydrograph] - Marks the start of a hydrograph section
! Name - Name of the hydrograph
! Event - Name of the rainfall event, if any
! Area - Contributing runoff area (SF or m²)
! t0 - The starting time of the hydrograph (seconds)
! dt - The time interval between flow ordinates (seconds)
! Flow - Flow values (CFS or m³/sec)
! (one or more flow values per line, separated by spaces and/or commas)
!
! Note that times are given in seconds (not hours) but may
! be readily converted by in-line multiplication, as shown below.
!
! The [hydrograph] marker allows each file to contain multiple hydrographs,
! such as the inflow or primary and secondary discharges of a pond.
!
! The "Event" parameter allows the file to contain multiple hydrographs for
! different rainfall events, while using the same hydrograph name. If "Event"
! is present, HydroCAD will automatically select the hydrograph that matches the
! project's current rainfall event name. If "Event" is not specified, HydroCAD
! will use the first hydrograph with the specified hydrograph name, regardless
! of any event that my be selected in the project.
!
FileUnits=English
Comment=Los Angeles County Example Hydrograph

[hydrograph]
Name=Inflow 1
t0=0
dt=.166667*3600
Flow=0 50 100 150 200 220 220 190 150 110 90 80
Flow=70 60 50 40 30 20 10 5 0

 
The way to import it is through a Link, and the "Import..." option. But, I've never gotten that to work.

I always use a Link, and the "Enter hydrographs manually" option. A lot of typing, but just set the time step, then have an Admin person sit down at your machine and enter, like a database.

Engineering is the practice of the art of science - Steve
 
"The way to import it is through a Link, and the "Import..." option. But, I've never gotten that to work."

If it doesn't work, what good is it ?

I am the "Admin person" sitting at my machine.

Thanks for you reply anyway.
 
"If it doesn't work, what good is it ?"

None, that I can ascertain. That is why I use the "Manual" option.

"I am the "Admin person" sitting at my machine."

I usually am, too. I usually enter my own regardless. From having tried a couple of times to create the .hce-deal, I think it is actually easier, and far less typing, than making an .hce.

"Thanks for you reply anyway."

You are very welcome.

Engineering is the practice of the art of science - Steve
 
"I usually enter my own regardless. From having tried a couple of times to create the .hce-deal, I think it is actually easier, and far less typing, than making an .hce."

So, why not fix the program to allow you to manually enter the hydrograph and then save it as an .hce text file ? Too simple ?
 
There are several ways you can use a link to specify a predefiend hydrograph. All work exactly as advertised:

1) With a "Manual Link", you can enter the hydrograph points by hand. The values will then be saved as part of the project file. This is the quickest option when you don't have too many hydrograph ordinates.

2) A variation of option (1): Right-click the manual link hydrograph table and use the "Load From File" option. After selecting Load From File, you can click Help for details on the supported file options.

3) Use a File Link to import the hydrograph from a .HCE file. Click the browse button to select the .HCE file. This option allows you to maintain the hydrograph data in a separate .HCE file. For details see the LinkTest.hce file in the HydroCAD Projects folder. This file format is also used to automatically interconnect sections of a larger project.

It sounds like you've already created the .HCE file, so all you need to do is create a link and select the "Import from file" option. If there are any problems reading the file, HydroCAD will provide a specific error message. An HCE file can even be used to import multi-event hydrograph data as discussed at
For further details, click Help on the applicable screen.
 
For Iha's benefit:

I finally got HydroCad to read my external hydrograph and route it through a detention basin. The "trick" is that when you seek to import the hydrograph you also have to go to "settings" and tell HydroCad that the rainfall is at least 0.04 inches. This is apparently the default minimum value for the rainfall. I don't know why. I don't understand why, if it is the default, it is not already set at 0.04 inches. It also doesn't make much sense since you could have flow into a basin without there being any rainfall. For example, you could have a variable speed pump pumping water into a basin thus producing a hydrograph without any rain falling.

Unfortunately, HydroCad does not allow you to export any of its reports to other software such as Word or Excel. You cannot even copy and paste them. This makes it impossible to easily incorporate the reports into your other work and leaves one stuck with the report format HydroCad produces. The graphics cannot similarly be edited.

good luck
 
Each HydroCAD project requires valid rainfall information to use for any subcatchments. In your case, there may be no subcatchments, but valid rainfall values are still required. There is no "trick" involved. HydroCAD will simply tell you that the rainfall data is missing. Just enter the values and you're all set. In your case, you may want to set the rainfall values to those used to generate the pre-defined hydrograph. This will make the reports more complete.

There are many ways you can export HydroCAD results and reports:

1) Click the "Export" button on any report window. The list of available file formats will vary depending on the exact report. (Graphical, tabular, etc.)

2) With HydroCAD 7.1 (and later) you can right-click any report and select "Copy to Clipboard".

3) The Settings|Export screen provides several options for spreadsheet generation. These settings will automatically generate spreadsheets for the entire project, and automatically updates them whenever you make changes. Using the spreadsheet as a database, you can generate essentially any type of report you choose.

For other export and printing options please see and
 
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