🌧️ Rules for NRCS Unit Hydrographs in InfoSWMM 📈

Subject: 🌧️ Rules for NRCS Unit Hydrographs in InfoSWMM 📈

When applying NRCS (Natural Resources Conservation Service) Unit Hydrographs for hydrological modeling in InfoSWMM adhere to the following rules or guidelines to ensure accurate hydrological simulations:

1. Curve Number (CN) Source 🗂️: Obtain the Curve Number (CN) from the NRCS_CN column in the Subcatchment Table, representing runoff potential based on soil type, land use, and treatment practices.

2. Time of Concentration (TC) ⏱️: The Time of Concentration, critical for hydrograph development, is sourced from the TC column within the Subcatchment Table.

3. Infiltration Model Selection 💧: Select the Infiltration Model according to the CN Infiltration Model Column in the Subcatchment Database Table to ensure consistency in infiltration calculations.

4. CN Consistency Across Tables 🔄: The CN value in the Soil Database Table must match the CN in the Subcatchment Database Table for uniform hydrological parameters.

5. Depression Storage and Initial Abstraction 🕳️➡️💧: If Depression Storage is zero in the Subcatchment Database Table, Initial Abstraction (IA) in inches will be internally calculated using the formula $��=0.2\times (1000\mathrm{/}��-10)$.

6. Initial Abstraction Calculation ✏️: Clearly state that Initial Abstraction in US units is $��=0.2\times (1000\mathrm{/}��-10)$, indicating the use of American measurement standards.

By following these emoji-highlighted guidelines 📝, hydrological modeling using NRCS Unit Hydrographs within InfoSWMM will be precise and reliable, leading to better water management outcomes. 💦🏙️

How to Export all of your Data to a Shapefile Using InfoSWMM

Subject:  How to Export all of your Data to a Shapefile Using InfoSWMM

You can do this easily by using three steps which are shown in Figure 1, Figure 2 and Figure 3.

Figure 1.  Export Manager Tool

Figure 2.  Link and Node Export Options

Figure 3. Parameter options for Export to the Shapefile

How to use the Flow Splitter in InfoSewer for Dendritic Networks

Subject:  How to use the Flow Splitter in InfoSewer for Dendritic Networks

InfoSewer, which is an extension in Arc Map, does need to have slit split defined where gravity mains merge together to determine the amount of flow in each of the downstream conduits (Figure 1).   The options for the flow splitterin each of the downstream links are:

1.       Automatic Allocation
2.       Fixed Flow Percentage
3.       Variable Flow Percentage and
4.       Inflow-Outflow Curve 

At an outfall where the invert of the outfall pipe is raised compared to the inverts of the incoming and outgoing pipes a flow split of Variable Flow Percentage or Inflow/Outflow curve may work better (Figure 2). 

Figure 1. Options for Performing a Flow Split in InfoSewer

Figure 2.  The Effect of the flow split can be used to model complex situations in a dendritic model with outfalls.

A SWMM 5 Model made from the Art of Jack Yerka

Subject:   A SWMM 5 Model made from the Art of Jack Yerka

The attached example SWMM 5 model has small rectangular conduits with a constant inflow based on a background image from Jack Yerka.

How to Save Node and Link Summary Tables in H2OMAP SWMM to Shapefiles

How to Save Node and Link Summary Tables in H2OMAP SWMM to Shapefiles

The export manager of H2OMAP SWMM is very flexible, you can export shape, MIF and CSV files but you have to do some copy and pasting to allow the program to export ALL of the node and pipe summary tables.  The export manager will export any node or pipe information in the DB hydraulic and information tables.  If you copy and paste, for example, the output pipe summary table to the Pipe information tables (Figure 1) then you can use the Export Manager (Figure 2) to save the shape file with tables(Figure 4) and view the shape file in Arc Map (Figure 4).  The TOC properties in Arc Map can be used to show the maximum d over D or maximum Q over Qfull values in Arc Map using this VBScript.

Function FindLabel ( [DOVEMAXD] )

  FindLabel = "" & FormatNumber([DOVEMAXD],2) & ""

End Function

Figure 1.  Copy and Paste the Pipe Summary information from the Output Tables to the Pipe Information  Tables.

Figure 2.  Select a link Shapefile using the Export Manager

Figure 3.  Save the Link Information and other data to a shape file.

Figure 4.  The created shapefile added to Arc Map and displayed using the Layer Properties of Arc Map

How to Use the Output Relate in Excel using H2OMAP SWMM

How to Use the Output Relate in Excel using H2OMAP SWMM

You have to perform the following steps:

1.       Make an Output Relate (using the Operations Tab of the H2OMAP SWMM Browser) which will be the same as the Pipe Summary Table in the Output Report Manager
2.      Run the model to make the Output Relate and then update the Relate (Figure 1)
3.      Using Windows Explorer navigate to the HSDB folder of your H2MAP SWMM project
4.      Continue to the Relate Subfolder and open up the Relate DBD file in Excel (Figure 2)
5.      You cannot SAVE this file but you can save is as a new Excel File

Figure 1.  Output Relate in H2OMAP SWMM to use the Pipe Summary Table

Figure 2.   How to Use the Output Relate in Excel

Advanced Labeling in InfoSWMM or H2OMAP SWMM to show MM or IN on a HGL Plot

Advanced Labeling in InfoSWMM or H2OMAP SWMM to show MM or IN on a HGL Plot

Here is how to get the maximum depth shown in millimeters or inches on a HGL Plot in InfoSWMM or H2OMAP SWMM– use the OTHER LINK Dimensions option.  You need to run the model again to have your new diameter shown on the HGL plot.  We use the output file to make the HGL plot and without a new model run the maximum depth will not be shown in either InfoSWMM or H2OMAP SWMM. 

Keys:

Use Other Units instead of feet or meters, and

Use the Advanced Labeling in InfoSWMM or H2OMAP SWMM

How to Use Two Control Curves in SWMM 5 to Simulate a Head Difference Rule

Subject:  How to Use Two Control Curves in SWMM 5 to Simulate a Head Difference Rule

The SWMM 5 control rules for Real Time Control (RTC) do not allow the rule to be governed by the head across the orifice but does allow rules based on the depth, head and inflow at any node.  If you have an Orifice in which you want the Orifice to be open when the head difference across the Orifice is either less than or greater than zero then and closed when the head difference is close to zero then you can use two Orifices (Figure 1) and two rules (Figure 2) to control the orifice setting for Orifice1 and Orifice2.  In attached file the two rules have the settings set to two control curves.  Orifice1 will start open and close gradually as the depth at Node UPNode increases, Orifice2 will start closed and gradually open when depth in Node DNode increases.  Possible variations are to control Orifice1 based on the DNode and node UPNode to control Orifice2.

RULE Orifice1

IF  NODE UPNode  Depth >= 0

THEN ORIFICE ORIFICE1 SETTING = Curve RuleOrf1

PRIORITY 10

RULE Orifice2

IF  NODE DNode  Depth >= 0

THEN ORIFICE ORIFICE2 SETTING = Curve RuleOrf2

PRIORITY 10

Figure 1.  Two Orifice Solution

Figure 2. Two Orifice solution to have control over the Orifice(s) at both the upstream and downstream nodes. 

Advanced Labeling in InfoSWMM or H2OMAP SWMM to show MM or IN on a HGL Plot

Advanced Labeling in InfoSWMM or H2OMAP SWMM to show MM or IN on a HGL Plot

Here is how to get the maximum depth shown in millimeters or inches on a HGL Plot in InfoSWMM or H2OMAP SWMM– use the OTHER LINK Dimensions option.  You need to run the model again to have your new diameter shown on the HGL plot.  We use the output file to make the HGL plot and without a new model run the maximum depth will not be shown in either InfoSWMM or H2OMAP SWMM.  

Keys:

Use Other Units instead of feet or meters, and

Use the Advanced Labeling in InfoSWMM or H2OMAP SWMM

The SWMM 4 Dynamic Wave Solution

The SWMM 4 Dynamic Wave Solution

The attached PDF file is a copy of Appendix C of the SWMM 4 manual explaining the three St Venant solutions in SWMM 4 / Extran 4.  The current SWMM 5 solution in its dynamic wave solution is an adaptive time step iterative solution of the ISOL Zero solution in SWMM 4.

The SWMM 4 Dynamic Wave Solution for ISOL=0

The SWMM 4 Dynamic Wave Solution for ISOL=0

The attached PDF file is a copy of the Extran 3 solution in the  SWMM 4 manual explaining the ISOL=0 solution in SWMM 4 / Extran 4.  The current SWMM 5 solution in its dynamic wave solution is an adaptive time step iterative solution of the ISOL=0 solution in SWMM 4.

Continuous Simulation using SWMM 5 LID and Groundwater Features in a Linked 1D/2D Network using InfoSWMM 2D for a 50 Year Period

Continuous Simulation using SWMM 5 LID and Groundwater Features in a Linked 1D/2D Network using InfoSWMM 2D for a 50 Year Period

A poster at the recent ECI conference on the Past, Present and Future of Watershed modeling.

How to Create an InfoSWMM model from CSV Files

How to Create an InfoSWMM model from CSV Files

An InfoSWMM model can be newly created from a CSV file but it helps to have a background map or shapefile to initialize the Arc Map project.  BEFORE initializing yourInfoSWMM map Add a data layer using the Arc Map command Add Data.   Create a new InfoSWMM project using the same spatial reference as your added shapefile (Figure 1).  Import the CSV files (Figure 2) and define the imported variables (Figure 3) followed by an Update Map from DB (Figure 4) which will draw your imported nodes and links on the Arc Map screen.  The updated Map will have the same coordinates as the background shapefile (Figure 5).  It is important to have the proper spatial reference for your imported data in Arc Map.

Figure 1.  Import a background shape file and initialize your InfoSWMM map to the coordinates of the shapefile.

Figure 2.  Import a CSV file for both pipes and nodes using the Import Manager of InfoSWMM

Figure 3.  Set up the Field Mapping between the CSV parameters and the Node and Link Parameters of InfosWMM.

Figure 4.  Update the Map from the DB tables you just imported using the command Force All Network.

Figure 5.  The imported model has the same coordinates as the original imported shapefile.

InfoSewer Minimum Travel Time Sensitivity

InfoSewer Minimum Travel Time Sensitivity

The three Run manager parameters, Maximum Number of Segments, Minimum Travel Distance and the Minimum Travel Time in InfoSewer and H2OMAP Sewer affect the shape and flow attenuation of the flow in a link.  The effect of decreasing the Minimum Travel Time is to reduce the peak flow and spread out the flow as the number of segments increases(Figure 1).  The larger the Minimum Travel Time, which has the effect of decreasing the number of segments in a link up the limit of the parameter Maximum Number of segments, the smaller the peak and the more attenuation of the flow in InfoSewer.

There is three ways to control attenuation in InfoSewer: (1) use the flow attenuation option, (2) increase the Maximum Number of Segments per link and (3) decrease the Minimum travel distance.    You can also use all three parameters to make more segments per link for long links and only a few segments for short links.

Figure 1.  Effect of the Minimum Travel Time in InfoSewer and H2OMAP Sewer

How to Create an InfoSWMM model from CSV Files, Alternate Method

How to Create an InfoSWMM model from CSV Files, Alternate Method

An InfoSWMM model can be newly created from a CSV file but it helps to have an idea of the maximum extents before you initialize the Arc Map project.  Use the ArcGIS default and Edit the extents of your future imported network (Figure 1).  Import the CSV files (Figure 2) and define the imported variables (Figure 3) followed by an Update Map from DB (Figure 4) which will draw your imported nodes and links on the Arc Map screen.  The updated Map should be within the extents of your defined spatial reference (Figure 5).  It is important to have the proper spatial reference for your imported data in Arc Map.  If you do not have the proper extents then when you update the Map from DB you will have a warning message "The coordinates or measures are out of bounds". 

Figure 1.  Import a background shape file and initialize your InfoSWMM map to the coordinates of the shapefile.

Figure 2.  Import a CSV file for both pipes and nodes using the Import Manager of InfoSWMM

Figure 3.  Set up the Field Mapping between the CSV parameters and the Node and Link Parameters of InfosWMM.

Figure 4.  Update the Map from the DB tables you just imported using the command Force All Network.

Figure 5.  The imported model has the same coordinates as the original imported shapefile.

The Structure of InfoSWMM in Arc Map

The Structure of InfoSWMM in Arc Map

Siphon Modeling in InfoSewer and Arc Map Atrribute Display

Siphon Modeling in InfoSewer and Arc Map Atrribute Display

Here is at typical view of  a siphon in InfoSewer, the rising links have a d/D of 1 and the dropping links typically have a d/D value less than 1.  The q/Q for the rising links is based on the slope and the dropping links typically have a q/Q less than 1 as the full flow is high due to the steep slopes.  You can show both the d/D and q/Q values in an Arc Map Display by using the following code.  I find it easier to first plot one variable using the InfoSewer Map Display followed by editing the TOC Properties for Pipes to show more than one variable at a time in the Label properties.

Function FindLabel ([D_OVER_D],  [Q_OVER_Q] )

If IsNull([D_OVER_D]) then Exit Function

FindLabel ="" &  FormatNumber([D_OVER_D],3) & "  d/D "  & "" &  FormatNumber([Q_OVER_Q],3) & " q/Q"

End Function

InfoSewer By Discharge Control for a PUMP

InfoSewer By Discharge Control for a PUMP

You can control the pumps in InfoSewer and H2OMap Sewer by using a Pump Control which will control the pump based on:

1.       Volume
2.      Level
3.      Discharge
4.      Inflow
5.      Time

If you use a By Discharge control the pump speed of the pump is increased or decreased to pump the incoming Wet Well flow based on the pump rules and the geometry of the Wet Well (Figure 1).

Figure 1.  By Discharge Control for  PUMP in InfoSewer and H2OMAP Sewer will change the Pump Speed of the pump to follow the Base Pump Flow Rules.

SWMM 4 and SWMM 5 St. Venant Solutions Contrasted

SWMM 4 and SWMM 5 St. Venant Solutions Contrasted

1. Compute at time t+delta t the values of dQ/dt for the Links and dH/dt for the Nodes from the properties at time t

2 Iterate at least 2 times until either all nodes and links are converged or a maximum of 8 iterations are reached

3. Use the values of Q and H at time t+delta t for the new time step

The SWMM5 Solution for Flow and Depth at each time step.  The new depth and new flow is always based on the old depth and old flow and normally converges fast as the flow is gradually varied.   The solution is iterative and implicitly uses the new depth and flow at each iteration.

The SWMM4 Solution for Flow and Depth is solved Explicitly at each time step.  The new depth and new flow is always based on the old depth and old flow and and a half and full time step during the time step.

InfoSewer Maximum Number of Segments Sensitivity

InfoSewer Maximum Number of Segments Sensitivity

The three Run manager parameters, Maximum Number of Segments, Minimum Travel Distance and the Minimum Travel Distance in InfoSewer and H2OMAP Sewer affect the shape and flow attenuation of the flow in a link.  The effect of decreasing the Minimum Travel Distance is to reduce the peak flow and spread out the flow as the number of segments increases(Figure 1).  The smaller the minimum travel distance, which has the effect of increasing the number ofsegments in a link up the limit of the parameter Maximum Number of segments, the smaller the peak and the more attenuation of the flow in InfoSewer.

There is three ways to control attenuation in InfoSewer: (1) use the flow attenuation option, (2) increase the Maximum Number of Segments per link and (3) decrease the Minimum travel distance.    You can also use all three parameters to make more segments per link for long links and only a few segments for short links.

Figure 1.  Effect of the Minimum Travel Distance in InfoSewer and H2OMAP Sewer