Storm Cad gutter

Hello Nasim,

Which product are you using? SewerGEMS? Maybe if you shared a snapshot of your system we can get an understanding of the type of system you are trying to model.

The gutter element captures the excess overflow from your catch-basin  and carries is downstream.

Typically your catch-basin is used to capture the runoff from your catchments. If however the runoff or inflow is more than the capacity of the inlet (catch-basin) the excess overflow is diverted to the gutter which carries it downstream.

The gutter element cross section (trapezoidal, irregular etc.) needs to be defined at the catch-basin.

I am sharing a few articles which can help you;

Modeling catch basin overflow into gutter

Why does the gutter need to be defined in both the catch basin and gutter element?

Hope this helps.

thank you so much for concidering my question. based on my knowledge, A catch basin is defined by user in order to carry related catchment flow so... how are we having excess flow in the first place? does catch basin diameter have effect on this matter?

In StormCAD, there is a surface gutter network and a below-surface pipe network. Catchbasins represent the above-surface inlet as well as the below-surface vertical vault. Above-surface runoff that approaches the catchbasin inlet (for example attached catchments) and some or all of that flow is captured by the inlet, and enters the sub-surface pipe network. For inlets on-grade, some of the flow to the inlet may not be captured and will bypass the inlet. This bypass flow will travel down the downstream gutter link element and as Yashodhan mentioned, the gutter element connectivity will determine the next inlet that the gutter bypass flow will approach. Meaning, the flow in that gutter will travel to the next downstream connected catchbasin and approach its inlet location. Here's an illustration to help:

If you are new to StormCAD, there are some helpful resources here: Learning Resource Guide for New Users of Bentley StormCAD

In StormCAD, there is a surface gutter network and a below-surface pipe network. Catchbasins represent the above-surface inlet as well as the below-surface vertical vault. Above-surface runoff that approaches the catchbasin inlet (for example attached catchments) and some or all of that flow is captured by the inlet, and enters the sub-surface pipe network. For inlets on-grade, some of the flow to the inlet may not be captured and will bypass the inlet. This bypass flow will travel down the downstream gutter link element and as Yashodhan mentioned, the gutter element connectivity will determine the next inlet that the gutter bypass flow will approach. Meaning, the flow in that gutter will travel to the next downstream connected catchbasin and approach its inlet location. Here's an illustration to help:

If you are new to StormCAD, there are some helpful resources here: Learning Resource Guide for New Users of Bentley StormCAD

thank you so much. your answer helped A lot.