Channel Design Considering Storage

[Gunns]

How do I model a concrete channel in HydroCAD so I can account for a channel slope and storage.

 

[psmart]

A normal reach routing (using the default Storage-Indication procedure) will simulate the storage effects of the channel. There is nothing special you need to do. For details please see the HydroCAD Owner's Manual and

http://www.hydrocad.net/reach.htm

HydroCAD-8 also adds the Muskingum-Cunge Routing procedure (as used in the current Win-TR20 software) which provides a complete kinematic routing. Again, please see the manual for details. But please note that this is a very complex routing procedure, and should be used only when necessary. Otherwise, stay with the default routing procedure.

 

[Gunns]

That is true but it does not account for tailwater

 

[psmart]

HydroCAD is a H&H program with the ability to handle pond-to-pond tailwater. The "pond" can be any level pool controlled by specific outlet devices.

Tailwater cability in a channel generaly requires a full water surface profile with specialized software such as HEC-RAS. See the previous link for details.

Perhaps if you explained exactly what you were trying to model I could be more helpful...

 

[Gunns]

I am modeling a concrete channel with a culvert. The channel has a 1:1 side slope with a max depth of 3.45ft, 0.3% slope and a 5.5ft base. The culvert empties into another concrete channel section to a pond with culvert.

 

[psmart]

Do you mean you are using a culvert to model the concrete channel? Although this may provide the tailwater-sensitive routing you're looking for, the culvert equations will not model the reach storage as you originally requested. You need to choose one or the other. See the Owner's Manual for details on the operation of each node.

Remember that the primary purpose of a HydroCAD model is hydrograph generation and runoff. Aspects of the drainage system that don't effect the hydrograph can often be omitted from the model. Please see

http://www.hydrocad.net/howto.htm

 

[Gunns]

No, I am modeling a concrete channel which flows to a culvert which connects the channell to the next section of channel. So I originally did a pond with culvert but couldn't account for the slope of the channel with storage. So then I switched to a reach and pond w/culvert with no storage (This way I get a flooding message).

 

[psmart]

If the channel discharge is being controlled by the culvert, such that the water in the channel forms a level pool, then you could include the channel storage as part of the pond/culvert node. To define the channel slope you will need to use the custom storage option. This lets you enter cummulative stage-storage data or stage-area data (based on contour lines.)

 

[Gunns]

Ok, great.

thanks

 

[ckidd]

This should be a simple question but I do not see the statement in the owner's manual when placing a horizontal cylinder storage that is at a slope what is the invert of the storage, the inlet elevation or the oulet elevation?

 

[psmart]

ckidd:

I've answered your question in a new thread so others can find it!