Maximum Inlet Capacity at Manholes?

[Carlos U]

Hi there,

I have a question related to how StormNET models inflow at catchbasins/manholes.

In XP-SWMM there is a field in the node's hydraulics layer called "Maximum Inlet Capacity" which allows you to determine the maximum allowable inflow rate at each node. Is there something like that in StormNET? Is there a way to model the maximum allowable rate without using a rating curve?

Thank you in advance,

Carlos

[Chris Maeder]

Yes, StormNET supports a maximum allowable inflow rate for inlets. Select the inlet and display the Inlets dialog. Then, from the Inlet Manufacturer drop down list, select Maximum Capture Cutoff. You can then define the maximum cutoff flow rate for the inlet.

[Carlos U]

Thank you for your response.

Then, in that case, do you need to specify an additional node/link such as a traplow or spillway in order to store the remaining volume (since a ponded area can't be defined) or would the stored volume at the inlet be reported in the output anyway?

Specifially, I am trying to model an area whose contributing catchment areas are to be controlled to a certain release rate before getting into the minor system. So my idea was to divert the Subbasin flow to an inlet specifying a maximum cutoff flow, which would then be connected (via a direct pipe or an outlet) to the receiving manhole in the minor system. Is this the right approach?

[Chris Maeder]

Depending upon how complex you want to model this device, you may want to take a different approach. If the key item is to model the storage at this location, I recommend that you create a storage node (i.e., detention pond) and then regulate the flow out of the storage node with an outlet structure.