Stormwater Management Model (SWMM) Information for watershed water quality, hydrology and hydraulics modelers (Note this Blog is not associated with the EPA). You will find Blog Posts and Twitter Embeds on the Subjects of SWMM5, InfoSWMM, InfoSewer, SWMMLive, InfoSWMM SUSTAIN, SWMM4 and SWMM in general.
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InfoSWMM (d/D v. Surcharge d/D)
Subject: InfoSWMM (d/Dv. Surcharged/D)
What is the difference between the output variables d/D and Surcharged/D in InfoSWMM and H2OMap SWMM
The d/D is calculated as link capacity based on the midpoint depth of water in the link orLink depth/ Link Maximum Depth
Since the depth in the link is restricted to the Maximum Depth the d/D value is always between 0 and 1
The Surcharged d/D is calculated from the end node depths at each end of the link
The two node depths are averaged and the value of Surcharged/D is the Average Node Depth / Link Maximum Depth,
The value of Surcharged/D varies from 0 to a large number depending on the maximum depths of the nodes and the possible surcharge depth of the nodes
The value of d/D is based on the middle of the link and the value of Surcharged/D is based on the average of the node depths at the end of the link. They may be and often are different. However, if you have a Surcharged/D greater than 1 it will indicate at least one end of the link is surcharged. A Surcharged/D may be greater than 1 with a d/Dless than 1 due to the ends of the node being surcharged and not surcharged.
· A Surcharged d/D indicates that at least one end of the link is Full, but · A d/D value less than 1 does not preclude that one end may be Surcharged.
Figure 1. Plot of d/D and Surcharged d/D in InfoSWMM.
Soffit Level (pipe technology)The top point of the inside open section of a pipe or box conduit. The soffit is the highest point of the internal surface of a pipe or culvert at any cross-section. The soffit is also referred to as the pipe obvert. So it is not quite the Crown of the Pipe. Here is an image I found that hopefully explains it better.
Engine Error NumberDescription ERROR 101: memory allocation error. ERROR 103: cannot solve KW equations for Link ERROR 105: cannot open ODE solver. ERROR 107: cannot compute a valid time step. ERROR 108: ambiguous outlet ID name for Subcatchment
New InfoSWMM linked 2D Link and 3D Node graphics help you understand one of the most critical outputs in any Stormwater, Combined Sewershed or Sanitary Sewershed Network Model the value and timing of how full the pipes and nodes are over time and how this changes during Wet Weather Flow (Runoff or Infiltration Inflow).These new graphs are included in InfoSWMM v 14.6 and InfoSWMM SA V2 (InfoSWMM SA is not an Esri Extension in ArcMap but uses Arc Engine for GIS processing power) has many new graphical and map display tools that help answer the following modeling questions in a easy to understand group of linked Time Track Graph, 2D Graphs and 2D Thumbnails. If you are modeling a Stormwater Network and need to know the d/D or depth over maximum depth over time and at the peak of the Runoff event you can view linked graphs as shown in Figure 1.If you are modeling a Sanitary Network and need to find the d/D for Rainfall Induced Infiltration and Inflow (RDII) you can see the RDII fl…