Aquifers in SWMM 5

Subject:   Aquifers in SWMM 5

Groundwater in SWMM 5 is modeled as two zones: (1) Saturated and (2) Unstaturated.  The data for the Groundwater Simulation consists of physical data in an Aquifer and elevation and flow coefficient and exponent data in the GroundwaterData.  The Aquifer data object can be applied to multiple Subcatchments but each Subcatchment has its own set of Groundwaterdata.  For example, in this model all of the Subcatchments share the same Aquifer data but each Subcatchment has different elevation and flow data – the labels on the basin are the groundwater elevations.

InfoSWMM and H2OMap SWMM Pump Summary Table

Subject:   InfoSWMM and H2OMap SWMM Pump Summary Table

The Pump Summary Table in Report Manager tells you how often the pumps turn on (Start-Up Count), the percent of the simulation time it was used (Percent Utilized) and the maximum, minimum and average flow for the pumps.

You can also see flows in the downstream links from the pumps in the force mains along with the pumps.

 

If you use the Mixed Graph Control you see the Pump flows and Link Flows on the same Graph

You can control the replay of the HGL Plot by altering the stepping time in Graph Settings

How to Use Domain Manager in InfoSWMM to Reduce the Output File Size

Subject:   How to Use Domain Manager in InfoSWMM to Reduce the Output File Size

If you want to save the output at a small report time step (2 seconds in this case) and you have a long simulation or large model then the reading of the graphicalo results may not be as speedy as you want.  You can save ONLY the DOMAIN to the output binary file however to make this smaller and faster to react.

Step 1.  Define your Reporting Time Step and Your Routing Time Step.  In this case we are routing at 1 second but saving the DOMAIN results every 2 seconds.

  

Step 2.  Clear your existing DOMAIN and Create a DOMAIN based on the area you are most interested in during the simulation.

Step 3.  Use the Advanced Tab in Run Manager and select Domain as the Output Scope – this will save only the Domain to the output binary file.

  

Step 4.  Run the simulation using Run Manager and then look at the output.  You are restricted to 8800 graph points but the number of points in the Report Table is unlimited.

Step 5. You can use the Data Plot Option (right mouse click) to see a subset of the larger than 8800 data points. 

 

InfoSWMM Report Manager and Field Statistics

Subject:  InfoSWMM Report Manager and Field Statistics

You can also use the mixed graph feature to plot the pump flow and the downstream flows on the same graph.  If you click on the Report command then you can also use aField Statistics command to see the Statistics for each Link and Pump.   The right mouse button for the Report also allows you to make a scatter plot and graph the flows in theforcemains versus the flows in the pumps.  

Dry Weather Flow in InfoSWMM and H2OMap SWMM

Dry Weather Flow in InfoSWMM and H2OMap SWMM

Dry weather flow can be added to any node in H2OMAP SWMM.  The dry weather flow is computed as the average flow * the monthly pattern * the daily pattern * hourly pattern * the weekend daily pattern to give the Dry Weather Flow at any time step (Figure 1).   Since the four types of patterns (Figure 2) are all multiplied together then for Saturday and Sunday the hourly pattern and the weekend hourly pattern will both be used.   This will have the effect of overestimating the flow if the multipliers are greater than 1 and underestimating theflow if the multipliers are less than one.  You should enter the  Pattern X for the Weekend Hourly Pattern in H2OMAP SWMM  where

X  = Weekend Hourly Pattern / Hourly Pattern

So that when the pattern X is multiplied by the Hourly Pattern the program will use the intended Weekend Pattern.

Figure 1.  How Dry Weather Flow is Computed in H2OMAP SWMM

Figure 2.  The Four Types of Time Patterns in H2OMAP SWMM, InfoSWMM and SWMM 5 

How to Make a Small Model out of a Large Model in H2OMAP Sewer and InfoSewer

Subject:  How to Make a Small Model out of a Large Model in H2OMAP Sewer

The process is easy if you use Domain and Facilities.  

Step 1.  Use the Trace Upstream Network Command in Utilities to find the upstream network from your node of interest.  The upstream network is saved to a Domain.

Step 2.  Use the Facility Manager to 1^st deactivate the whole network and then 2^nd to add the Domain to your Facility or the nodes and links that you will simulate

You now have a smaller network to examine in Detail.  You may have to make a temporary Outfall node to run the model if there are no Outfalls in the model.

SWMM 5 QA and Application Manuals on the EPA Web Site

Subject:   SWMM 5 QA and Application Manuals on the EPA Web Site

The EPA Web Site has three manuals that you can download at http://www.epa.gov/nrmrl/wswrd/wq/models/swmm/#Downloads

1.   SWMM Applications Manual
2.   SWMM 5 Quality Assurance Report
3.   SWMM 5 Users Manual

Infiltration Data in SWMM 5

Subject:  Infiltration Data in SWMM 5

If you are using Non linear Reservoir Modeling in SWMM 5 there are

1.   Five parameters for Horton Infiltration,
2.   Three parameters for Green-Ampt and
3.   Two parameters for CN infiltration, one parameter (conductivity) has been deprecated by the EPA in SWMM 5.   The Drying Time is used to regenerate the Infiltration Rate for continuous simulation.  Only two parameters are now used for CN infiltration:  The CN value itself and the drying time.

Aquifer and Groundwater Objects in SWMM 5

Subject:   Aquifer and Groundwater Objects in SWMM 5

There are two types of data objects in SWMM 5 to describe the Groundwater flow component.  There is a Groundwater data object associated with a Subcatchment that describes flow equations, the interaction between the Subcatchment infiltration and the Groundwater component and an Aquifer data object that describes the characteristics of the Aquifer that may span one or more Subcatchments.  The Groundwater data is specific to one Subcatchment but the Aquifer may

 

SWMM 5 Culvert Data from FHWA, HDS No. 5, Hydraulic Design of Highway Culverts, 1985

Subject:  SWMM 5 Culvert Data from FHWA, HDS No. 5, Hydraulic Design of Highway Culverts, 1985

If you use the culvert option in later versions of SWMM 5 then when the inlet control equation flow is less than the computed St Venant flow then the FHWA equations will be used for the current iteration in the SWMM 5 Dynamic Wave Solution.

Three Hidden Secrets to Speeding up your SWMM 5, H2OMAP SWMM or InfoSWMM Model

  

Minimum Time Step               Average Time Step        Maximum Time Step

Minimum Time Step (sec)             0.984

Average Time Step (sec)              9.071

Maximum Time Step (sec)            30.000

Percent in Steady State (%)          0.000

Average Iterations per Time Step  4.821

Use a maximum time that will lower your average iterations per time step to speed up the simulation,decrease the maximum time step to lower the number of iterations, use equivalent conduit lengthening to increase the minimum time step, the model is fastest if the minimum and maximum time steps are not too small or large compared to the average time step.  Adjust the stopping tolerance and the number of iterations if you can to speed up your model You can also decrease the number of iterations or the stopping tolerance to speed up the model or improve the continuity error of themodel.   If you are doing a continuous simulation then you can have a reduced graphical output data set to speedup the simulation

  

If you have a duo or quad core computer another option to speed up the simulations is to use 1, 2, 3 or 4 cores for the simulation 

Elevation Interpolation from a Contour in H2OMAP SWMM

Subject:  Elevation Interpolation from a Contour in H2OMAP SWMM

The node invert elevation or the node maximum depth can be interpolated if you use the Elevation Interpolation Tool inH2OMAP SWMM.

Steps	Action
1.   Make a Contour Plot of the Node Invert Elevations.
2.   The Created Contours are now a layer inH2OMAP SWMM.
3.   Recreate the Invert Elevation from the Contourby using the Value Field and Interpolate Field.
4.   You can  also estimate the Maximum Depth of the Node from the Contour and the known Node Invert Elevation.

How to see what you have in the various scenarios of InfoSWMM

Subject:  How to see what you have in the various scenarios of InfoSWMM

How to see what you have in the various scenarios – a tool I use a lot is Scenario Explorer which shows you how to see thevarious datasets associated with a data set along with the relationship between the Base and Various Child Scenarios.

 

SWMM 5 Inlet Control Culvert Equations

Subject:   SWMM 5 Inlet Control Culvert Equations

The newer option for SWMM 5 culverts uses three culvert classifications and associated equations to compute the inletcontrolled flow into a culvert using the FHWA (1985) equations.  The culvert code in the culvert.c code of SWMM 5 uses:

1.   Two Equations for Unsubmerged culvert flow,
2.   One Equation for the Transition flow, and
3.   One Equation for Submerged flow.

How Does the Green Ampt Initial Moisture Defiict Work in InfoSWMM and SWMM 5?

Subject:   How Does the Green Ampt Initial Moisture Defiict Work in InfoSWMM and SWMM 5?

This graph shows the values of the internal SWMM 5 parameters for Green Ampt Infiltration for the pervious area of a Subcatchment during a simulation.  The parameters are:

·         Soil Moisture = IMD Max – (FUMax – FU)/Upper Soil Zone Depth
·         FU or current moisture content of the upper zone of the of the soil
·         FUMax which is the saturated moisture content of the upper zone in feet and stays constant during the simulation
·         IMD Max is the user defined Initial soil moisture deficit and is a fraction

Figure 1.  How Soil Moisture changes over time.

Figure 2.  Soil Moisture and IMD are related – the Soil Moisture has a maximum of IMDMax.

High and Low Estimates of InfoSWMM/ICM Subcatchment Dimension for SWMM Hydrology

High and Low Estimates of InfoSWMM/ICM Subcatchment Dimension for SWMM Hydrology

These are the estimates for both SWMM 5, InfoSWMM and ICM SWMM Hydrology, the low estimate is 0.2*SQRT(Area in Feet) and the High Estimate is 5*SQRT(Area in Feet), Figure 1.  You can use higher or lower numbers to calibrate to monitored data but these are just guidelines using the InfoSWMM Subcatchment Manager Width Tool (Figure 2).

Table 1.  High and Low Estimates of the ICM Subcatchment Dimension for SWMM Hydrology or the SWMM 5 Subcatchment Width.

Subcatchment Area  (Acres)	Low Estimate  Width (Feet), W = 0.2*SQRT(Area)	High Estimate  Width (Feet), W =5*SQRT(Area)
1	41.74	1,043.55
5	93.34	2,333.45
10	132	3,300.00
25	208.71	5,217.76
50	295.16	7,379.02
100	417.42	10,435.52
200	590.32	14,758.05
300	722.99	18,074.84
400	834.84	20,871.03
500	933.38	23,334.52
600	1022.47	25,561.69
700	1104.39	27,609.78
800	1180.64	29,516.10
900	1252.26	31,306.55
1,000	1320	33,000.00
5,000	2951.61	73,790.24
10,000	4174.21	104,355.16
50,000	9333.81	233,345.24
100,000	13200	330,000.00

Figure 1  InfoSWMM Subcatchment Manager Width Estimator.

How do V-notch weirs work in SWMM 5?

How do V-notch weirs work in SWMM 5?

Hi Keith, As you change the Length which is actually the Top Width you change the area and hydraulic radius of the Weir. 

The height of a V-Notch weir is the Height Value in the SWMM 5 Weir Property Dialog (Figure 1) 

The Length in the Dialog for a V-Notch is the Top Width of Triangular Shaped V-Notch Weir. 

The slope of the sides of the V-Notch Weir is Square Root (1 + Top Width / Height / 2 * Top Width / Height / 2)

The full area is the Height * Height * Side Slope

The hydraulic radius is the Height / ( 2 * Height * Side Slope)

The two values Height and Length for a SWMM 5 V-Notch Weir determines the area, hydraulic radius and side slope of the weir.

Figure 1.   Parameters for a V-Notch Weir in SWMM 5

How to Import Subcatchments from GIS into InfoSWMM

How to Import Subcatchments from GIS into InfoSWMM

Step 1:  Add your shapefile using  the Add Data command.

Step 2:  Your imported shape file has no subcatchment data before we initialize the project.

Step 3:  Add your subcatchment data using the GIS Exchange Cluster Import

Step 4:  Now you have the Subcatchments in the DB Tables and can now calculate the area.

=====================================

Step 1:  Add your shapefile using  the Add Data command.

Step 2:  Your imported shape file has no subcatchment data

Step 3:  Add your subcatchment data using the GIS Exchange Cluster Import

  

Step 4:  Now you have the Subcatchments in the DB Tables and can now calculate the area.

We still have to enter 1/10000 to get the right units for subcatchment area using the Auto Area Calculation under Tools preferences.  You first import the shape file and then you turn on Auto Area Calculation, enter a value for the Area Scaling Factor and then use the tool Utilities, Update DB from Map, All Subcatchment to get the Subcatchment Area in hectares.