×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

modeling pipe into a pond

modeling pipe into a pond

modeling pipe into a pond

(OP)
Okay, trying to get familiar with pond routing again.  I have a detention pond with an outlet structure.  The inlet is a storm sewer pipe system.  I have used Landdesktop to design the storm sewer and have a flow from the last segment of pipe.  How do I model this into my pond?  I can't seem to figure out how to enter the flow.

RE: modeling pipe into a pond

sprtsnut5,

I do not know the model requirements in your location.  However, it is comon for storm sewers to be sized using the rational method and ponds to be routed using SCS methodologies.  While there are those with magic formulas to make a correlation...its really apples and oranges.

On a typical project, I will layout my sewer network (without sizing or design yet), I will establish SCS subcatchments that flow to appropriate ponds (larger than 1 per inlet...may even be 1 per pond), I then do the pond design.  NOW, I have a tailwater elevation for doing the sewer network design.

The shorter answer:  I would create a Subcatchment in Hydrocad and use SCS to establish pond inflow.

RE: modeling pipe into a pond

(OP)
This is geeting there... I'm just trying not to have to recreate one or the other, since Hydrocad doesn't model the pipe system.  By the way, we do everything with Modified Rational.  Any other options out there?

RE: modeling pipe into a pond

You can use a link to introduce the pre-existing hydrograph into your HydroCAD model.  For details see www.hydrocad.net/link.htm

As TerryScan suggested, generating the runoff in HydroCAD should also be considered.  This will make it much easier to run multiple storms and make other changes.  Otherwise you'll have to reload the link with a different Hydrograph each time.
 

Peter Smart
HydroCAD Software
www.hydrocad.net
 

RE: modeling pipe into a pond

" By the way, we do everything with Modified Rational.  Any other options out there? "

Yes, there are very many other options "out there"; almost all of them better than "Modified Rational".

There are at least two versions of the modified rational method. Do you mean the one which produces a fictional trapezoidal hydrograph, or do you mean the one developed by Los Angeles County which produces a more realistic hydrograph for an assumed rainfall pattern ?

You can also use the NRCS ( SCS) method, the Santa Barbara Urban Hydrograph method, the Clark Unit hydrograph method, the Snyder Hydrograph method or any of their many local variations.

By far the best method would be one which, unlike these, has been calibrated !

Whichever method you choose, or are required to use, expect errors of estimate of +/- 30% to 100%.

good luck

  

RE: modeling pipe into a pond

Since you're using HydroCAD, I would definitely recommmend the SCS/NRCS method over Rational method.  Although HydroCAD can do both, SCS/NRCS is actually a lot easier to use, and it's much better for any volume sensitive calculations, such as pond routing.

For details on the SCS/NRCS method see www.hydrocad.net/runoff.htm

If you must use Rational method please read www.hydrocad.net/rational.htm
 

Peter Smart
HydroCAD Software
www.hydrocad.net
 

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close