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!
  • Students Click Here

*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


Raising the inside floor of a Catch Basin 2"

Raising the inside floor of a Catch Basin 2"

Raising the inside floor of a Catch Basin 2"

Hello - this may be very trivial but I have a project in construction where we need to raise the outflow pipe going into an existing 36" precast catch basin (re-routing site storm around a new structure and in order to make up the delta in slope within the system, we are reducing the "drop" within this particular existing catch basin. In order to avoid 2" of standing storm water at the bottom, I was thinking the contractors could grout the bottom up to the invert of the new outflow pipe. Will this work for this application? Is there an industry standard? This is privately-maintained storm drain on a college campus. The District has bare bones construction standards/specifications.

Any help would be appreciated! Thanks!

RE: Raising the inside floor of a Catch Basin 2"

Most standard catch basin designs i've seen include a sump below the outflowing pipe so there is always stormwater standing in the basin. Our standard detail is 24" sump. This gives you a reservoir for sand, gravel, heavy debris, etc... so that routine maintenance can be done by periodically cleaning basin sumps alone... instead of cleaning basins AND the lines between them. Have you considered being 'OK' with the small amount of standing water?

If this was a sanitary sewer manhole (instead of a stormwater catch basin), i would say grout it up.

RE: Raising the inside floor of a Catch Basin 2"

Normally you will need to have a drop or sump of 2-in or more between storm drain inflow and outflow, but in your case i think it should be ok.
This should work fine.

RE: Raising the inside floor of a Catch Basin 2"

Make sure to check your regulations and design criteria for the agency that will approve the design.

RE: Raising the inside floor of a Catch Basin 2"

Where I'm at it's standard to use flowable fill when abandoning structures but lightweight concrete for this type of application. We had to raise the bottom of a manhole 3 ft once and used lightweight concrete. But yes, like the others said with this small of an invert change just leave the sump as is.

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


eBook - Manufacturing the Cars of Tomorrow
In this ebook, we'll explore how additive manufacturing is going to transform the way cars are made. This includes commentary from thought leaders such as Ford's CTO, Ken Washington, Customer case studies of ways 3D printing is being used today, and a variety of part examples where 3D printing is already impacting how automobiles are made. Download Now
White Paper - Smart Manufacturing for Semiconductor
New technologies and approaches present great opportunities for semiconductor manufacturers to achieve high levels of innovation, yield and improvement. This white paper explores some of these cutting-edge technologies and how they can be applied effectively in the semiconductor industry. Read about how Smart Manufacturing is transforming the semiconductor industry. Download Now
White Paper - Analysis and Simulation in Aircraft Structure Certification
Organizations using simulation and analysis tools effectively see the benefits in their ability to achieve certification faster and with drastically less total cost than those who do not maximize these tools. Read this White Paper to learn about how digital tools such as analysis and simulation help in aircraft structure certification. 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