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How do I route a TR-55 hydrograph through a network?

	Product(s):	PondPack
	Version(s):	CONNECT Edition, V8i, V10
	Area:	General

Problem

How can I route a TR-55 hydrograph through a network?

Solution

PondPack CONNECT Edition and PondPack V8i

1) Go to Analysis > Calculators > TR-55 Tabular Hydrograph

2) Create a new TR-55 hydrograph using the new icon. Fill in the information on the tabs and check the box for "store hydrograph", then use the compute arrow to compute and store the hydrograph.

3) In the properties of your catchment, choose "user defined hydrograph" and select the stored hydrograph from the "hydrograph" dropdown.

Older PondPack versions (V10)

NOTE: It is much easier and more precise (than the TR-55 method) to use the SCS unit hydrograph subarea option to calculate runoff hydrographs and route them through simple or complex networks. To route a TR-55 hydrograph through a network, follow these steps:

1) Create a TR-55 datasheet and save the hydrograph data to a hydrograph file.

2) To do this, click on Options and select Store in Hydrograph. Fill out the appropriate data.

3) Close out of the TR-55 datasheet. Create a hydrograph queue node and in the hydrograph node, specify the hydrographs for each of the storm(s) you are using.

4) Fill out the remaining information as necessary (i.e. pond data, etc) Calculate the network.

SewerGEMS, SewerCAD and CivilStorm

Although some versions of these products may mention TR-55 in the Help documentation, that information was incorrectly copied from the PondPack help documentation. SewerGEMS, SewerCAD and CivilStorm currently do not have the same TR-55 Calculator tools that PondPack has. If you have access to PondPack CONNECT Edition you can follow the steps above to calculate a hydrograph, then copy and paste the table of time and flow to a user defined hydrograph assigned to a catchment in SewerGEMS, SewerCAD or CivilStorm.

Note that TR-55 was a simplified procedure that was used when engineers didn't have computers that could properly crunch the numbers for them. It was simplified from TR-20. TR-20 is typically preferred in modeling software and is the basis of the SCS Unit Hydrograph method available in SewerGEMS, SewerCAD, CivilStorm and PondPack.