SURCHARGE NETWORK

Hello,

Surcharging is allowed in StormCAD, though if the hydraulic grade is above the ground elevation (i.e., if there is flooding), storage cannot be computed (see this link for information: communities.bentley.com/.../11166.why-is-the-hgl-reset-to-rim-elevation-for-flooded-structures).

We may need some additional information on the optimization that you are trying to do. If you can provide some additional information, that will be useful.

Regards,
Scott

hello, thank you very much for your answer, well i still have some question, i will be grateful if you can answer me.
what i am trying to do is to make the road flooded so i can make my system work as a surcharge one and by this situation i can optimize my network and use smaller diameters.
how i can use the stormCAD to solve this? is it possible?

Hello Daniel,

As mentioned by Dr. Tom already in his reply, you can use StormCAD for design of such surcharged network, but why would you do that? Why would you want your network to surcharge by using small diameter.

When the elements are surcharged, you will see a notification about that, or you can see that in the pipe properties.
Or you can color code the elements based on field - Is ever surcharged? using element symbology

Hello sushma,

Thank you for your answer as well for Dr.tom's answer but i know all this you have mentioned, my problem is how stormCAD can define the surcharge network? will it give me the spread of the flow flooded on the road?
now i am going to explain a lot about the problem i am facing:
i have to design a stormwater network for a 100yr flow using a 10yr flow system, that's mean the difference between the 10 yr and 100 yr flow will be flooded on the road and this will make the 10yr flow system work as surcharged flow.i have to know the spread of this flow to know how to convey it.
one of my solution is to convey this flow with the roads till the low point where i can put a tank to take all the difference flow between 100 and 10 yr. and the overflow of the 10 yr flow will be conveying in a small pipe in the tank at an elevation higher than the level of (the flow we have talked about) so by this solution the system will work in the peak time before the tank in 10 yr flow and after the tank it will work for the 100 yr flow.

StormCAD can calculate depth or flow and surcharging in pipes, inlets and manholes. It can tell you gutter depth and spread. It does not calculate 2-D overland flow because that would require a huge amount of very precise data that most systems don't have.

If you need to perform dynamic calculations such as the time it takes to fill or train a tank, you are better off using CivilStorm or SewerGEMS.

Daniel,

We have a wiki article that explains the difference between the StormCAD solver (GVF Rational engine) and the CivilStorm solver (Implicit or SWMM dynamic engine) that will help explain when to use each solver for the results that you're looking to achieve.

Regards,

Mark

Hi Daniel,

Just to confirm - are you referring to surcharging or flooding? As Tom and others pointed out, StormCAD can accurately calculate a *surcharged* pipe, where the HGL is above the top of the pipe (the pipe is flowing full). However, when the HGL rises above the rim/ground elevation of a structure such as a catchbasin and the structure *floods* , StormCAD does not calculate the overflow and resets the HGL to the rim elevation (see link in Scott Kampa's first reply). This means that water will not overflow into the street from a flooded catchbasin, and the inlet capture calculations will continue to assume no tailwater conditions (no influence from the flooded structure).

So, I would agree with the suggestion of CivilStorm, which can handle flooding and overflow, including into the above-surface gutter system.

Hi Daniel,

Just to confirm - are you referring to surcharging or flooding? As Tom and others pointed out, StormCAD can accurately calculate a *surcharged* pipe, where the HGL is above the top of the pipe (the pipe is flowing full). However, when the HGL rises above the rim/ground elevation of a structure such as a catchbasin and the structure *floods* , StormCAD does not calculate the overflow and resets the HGL to the rim elevation (see link in Scott Kampa's first reply). This means that water will not overflow into the street from a flooded catchbasin, and the inlet capture calculations will continue to assume no tailwater conditions (no influence from the flooded structure).

So, I would agree with the suggestion of CivilStorm, which can handle flooding and overflow, including into the above-surface gutter system.