Steady State Flow Analysis in InfoSWMM using an External Flow Time Series

Subject:  Steady State Flow Analysis in InfoSWMM using an External Flow Time Series

This can be easily created using a few steps in InfoSWMM.  The flow ramp is in the Routing Interface File.  The advantage is that you are able to have different ramps for the various nodes using this method.

Step 1:  In Run Manager Set up the Process Models Options to use just the External Inflow and NOT the Dry Weather Flow

Step 2.  Create the External Inflows File (see the help file for the format)

SWMM5 Interface File

300  - reporting time step in sec

1    - number of constituents as listed below:

FLOW CFS

2    - number of nodes as listed below:

36

24

Node             Year Mon Day Hr  Min Sec FLOW     

36               2002 01  01  00  00  00  0.000000 

24               2002 01  01  00  00  00  0.000000 

36               2002 01  01  01  00  00  1000.000000 

24               2002 01  01  01  00  00  1000.000000 

36               2002 01  02  01  00  00  1000.000000 

24               2002 01  02  01  00  00  1000.000000   

This file loads two manholes with a ramped inflow up to 1000 cfs to again drown out the wet wells and cause the pumps to have a steady flow.

Step 3.  Use the Tab File command and use the created External Inflows File

Step 4.  Run the simulation and see if the pump flows are constant.

InfoSWMM and Arc GIS for Surcharge and Flooded Time

Subject:  InfoSWMM and Arc GIS Layer Properties for Surcharge and Flooded Time

An important advantage of using InfoSWMM is the ability to use all of the Arc GIS layer and programming tools.  For example, you can graph the model results for the flooded and surcharged time in a node using a Bar/Column plot to show the surcharge time in the node and the flooded time in the node.  A flooded node is always considered to be surcharged but a surcharged node does not always flood.  The surcharge level is any water surface elevation above the highest connecting crown elevation but the flooded time is a water surface elevation at or exceeded the rim elevation of the node.

InfoSWMM and Arc GIS Layer Properties for Surcharge and Flooded Time

InfoSWMM and Arc GIS for Create Graphs Using Network Data and Model Results

Subject: InfoSWMM and Arc GIS for Create Graphs Using Network Data and Model Results

An important advantage of using InfoSWMM is the ability to use all of the Arc GIS layer and programming tools.  For example, you can graph the model results in Bar,  Pie, Scatter, Bubble or other types of Graphs once the model data and model result layers are Joined together.  The image below shows a thematic mapping for Node Flooding, Conduit Force Main Type and a Pie and Bar Chart of Node Flooding Time and the Q Full in the links, respectively.

World Wide Visitor Coverage of WWW.SWMM2000.COM

Note:  For the 1^st time in 4 years we have had a visitor from Central Asia.  This now means we have had visitors from all Google defined Geographic Regions on Earth even though we still have not had visitors from every country at www.swmm2000.com  The statistics below exclude the 58 percent visitors from North America but overall we have had on September 3rd, 2011 (1st column) compared to August 3, 2013 (2nd column)

1.   40,190 Visitors to 78,840 Visitors in 2013(Cumulative)
2.   22 Continental Regions to 23 Regions
3.   157 Countries  to 179 Countries
4.   5951 Cities to 6235 Cities
5.   100,180 Pageviews in 2011 to 193,142 Pageviews in  2013(Cumulative)
6.   86 Languages to 106 Languages

Statistics from 2013 

Statistics from 2011

InfoSWMM 2D Layer Properties and Mesh ID

Subject:   InfoSWMM 2D Layer Properties and Mesh ID

You can use the Layer Properties for layers in the Table of Contents to see the Mesh ID and other simulation data for the 2D mesh in InfoSWMM 2D.  The Mesh ID can be seen using the Labels/Label Expression command and if you use an expression you can see the results data as well on the mesh.  The Mesh ID is used as the label as well in the 2D Output modeling report.  The Net Inflow and Net Outflow is by Mesh ID.  In this example, the flow comes out of Node 80408 to Mesh ID 131 and enters the 1D network again at Mesh ID 848.

Detention Pond Infiltration and Evaporation Losses in SWMM 5

Subject:  Detention Pond Infiltration and Evaporation Losses 

You can also add a storage pond infiltration and surface evaporation losses to the pond.  The surface evaporation is added to theinfiltration (computed from the green ampt parameters); a storage volume summary listing the average and maximum volume and the percent loss from the combined infiltration and evaporation from the ponds.  The pond infiltration loss during a time step is basd on the areal weighed average depth, the Green Ampt infiltration and the Area of the pond.

Detention Basin Basics in SWMM 5

Subject:  Detention Basin Basics in SWMM 5

What are the basic elements of a detention pond in SWMM 5?  They are common in our backyards and cities and just require a few basic elements to model.  Here is a model in SWMM 5.0.022 that even has a fountain in the real pond – which we not model for now.   The components of the model are:

1.   An inlet to the pond with a simple time series – a subcatchment can be added to it in a more complicated model but for now we will just have a triangular time series,

2.   A pipe to simulate the flow into the pond from the inlet,

3.   A Storage Node to simulate the Pond that consists of a tabular area curve to estimate the depth and area relationship,

4.   A Storage Node to simulate the Outlet Box of the Pond

5.   Two Small Rectangular Orifices to simulate the low flow outflow from the pond at an elevation less than the weir

6.   A large rectangular orifice to simulate the normal inflow to the Box

7.   A rectangular weir to simulate the flow into the box when the pond water surface elevation is above the box

8.   The outlet of the Box is a circular link with a Free outfall as the downstream boundary condition

9.   The flow graph in the image shows the flow into the box starts from the two small orifices, next from the large orifice and finally from the top of the box or the weir.

How the State InfoSewer solution solves for the link flow and node heads

Note: State InfoSewer solution solves for the link flow and node heads

Here is an example of how the Steady State InfoSewer solution solves for the link flow and node heads or depths:

•         1^ST Flow is computed in each link and d and d/D is calculated based on pipe flow and manhole loading data and not the adjusted data from the 2^nd pass.

•         2^nd InfoSewer adjusts the link depth based on the manhole head and lists the adjusted depth in the browser and the Report Table after the manhole depths are calculated from downstream to upstream in the network.

•         Result: The HGL graph shows the link d and d/D based on pipe flow not the adjusted depth so you are looking at the results of the 1^st pass in the links and the 2^nd Pass in the Nodes in a HGL Plot  for a Steady State Simulation.

Here is one example of this sequence of events: The downstream head at the outfall causes a backwater condition in all of the links.  The d/D and q/Q is based on the manhole loading flow in the 1st pass and indicates the pipe is NOT full. However, in the 2nd Pass where the manhole depths are calculated from downstream to upstream the effect of the downstream boundary condition is felt.  The head shows that there is a full downstream boundary condition which is reflected in the condition of backwater and in the adjusted depth value.  The links are now full and the full depth is reflected in the value of the adjusted depth and the graphical presentation.

How to interpret this result:

1.   Based on the manhole loading to the network the pipes are NOT full which is indicated by the value of d/D and q/Q, however

2.   Based on the head calculations which account for downstream boundary conditions the pipes are full due to the backwater effect.  The backwater condition is reflected in the value of the adjusted depth – the adjusted depth shows the pipe to be full.

Figure 1.  Backwater is caused by the downstream boundary condition and shows full pipes but d/D is less than 1 based on the 1^st Pass Link Flow Values.

Figure 2. InfoSewer solves for the flows in the links in the 1^st pass and the heads at the nodes in the 2^nd pass for the Steady State solution.

Figure 3.  Pipe Summary Table Shows the Pipe Adjustments based on 2^nd Pass Head calculations and the d/D and q/Q values from the 1^st Pass Link Flow Calculations.

Figure 4:  Two Pass Solution for InfoSewer (1) Flow and (2) Head

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 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.

Additional Features in InfoSWMM and InfoSWMM SA

Subject:   Additional Features in InfoSWMM and InfoSWMM SA

The additional features supply the tools for your modeling or modelling:

1.   Dry Flow Allocation for your Sanitary or Combined Sewer Model
2.   Subcatchment Manager to estimate the impervious, slope, width and area of your Subcatchments,
3.   RDII Analyst to estimate the Infiltration/Inflow into your Sanitary Network,
4.   Calibrator to help calibrate the model data to monitored data
5.   Designer to design new links to prevent flooded or surcharge,
6.   InfoSWMM 2D to link your 1D network to a 2D network
7.   CapPlan for Capacity Analysis and Capital Planning,
8.   Pond Design for Stormwater Ponds
9. Import from InfoSewer and Import/Export from SWMM5
10. Hydraulic Engines for InfoMaster Sewer

Contrasting Add On Features for InfoSWMM and H2OMap SWMM

InfoSWMM	H2OMAP SWMM
Calibator	Calibator
Conduit Storage Synthesizer	Conduit Storage Synthesizer
Designer	Designer
DWF Allocator	DWF Allocator
InfoSWMM 2D	n/a
InfoSWMM CapPlan	InfoSWMM CapPlan
NetView to KML	NetView to KML
Pond Design	Pond Design
RDII Analyst	RDII Analyst
Risk Assesment Manager	n/a
Subcatchment Manager	n/a
InfoSWMM SFEM	n/a
An Engine for InfoMaster Sewer	An Engine for InfoMaster Sewer
Imports InfoSewer, SWMM 5, H2OMAP SWMM, HEC-RAS Geometry	Imports H2OMap Sewer, SWMM 5, InfoSWMM, HEC-RAS Geometry

Variables for Controlling the Continuity Error in InfoSWMM and H2OMAP SWMM compared to SWMM 5

Subject:  Variables for Controlling the Continuity Error in InfoSWMM and H2OMAP SWMM compared to SWMM 5

Time step is always a key parameter in SWMM 5 as it is the main parameter for a user to adjust in case of a significant continuity error.   InfoSWMM has additional flexibility and allows the user to control the number of Picard iterations and the Node continuity stopping tolerance.   SWMM 5.0.022 has the number of iterations fixed at 8 and the stopping tolerance fixed at 0.005 feet.   The stopping tolerance is important because it controls the number of iterations during a time step.  For example, if all of the Nodes have a current and former iteration depth difference (absolute) less than 0.005 feet then the time step is deemed converged and the node and link flow computations are stopped for that time step.  In SWMM 5 since the stopping tolerance is fixed then your main option is to reduce the time step.  In InfoSWMM you can also decrease the stopping tolerance, increase the number of iterations or decrease the time step.  In most models it is best to alter all three parameters for the fastest model.  For example, a slightly smaller maximum time step or a smaller variable time step adjustment factor, more iterations and a smaller tolerance will normally work better than just lowering the time step.

Iterations and Stopping Tolerances

SWMM 5 Clocktime RTC Rules for Pumps, Weirs and Orifices

Subject:  SWMM 5 Clocktime RTC Rules for Pumps, Weirs and Orifices

You can use the Control or RTC rules in SWMM 5 to adjust the settings of the weirs, pumps and orifices based on the clock time each day of your simulation.  Here is an example that will adjust orifice height every ½ hour for 7 orifices at one time using two sets of rules.

RULE R1a 

; Half hour setting

IF SIMULATION CLOCKTIME = 0:30:00 

OR SIMULATION CLOCKTIME = 1:30:00  

OR SIMULATION CLOCKTIME = 2:30:00 

OR SIMULATION CLOCKTIME = 3:30:00 

OR SIMULATION CLOCKTIME = 4:30:00 

OR SIMULATION CLOCKTIME = 5:30:00 

OR SIMULATION CLOCKTIME = 6:30:00 

OR SIMULATION CLOCKTIME = 7:30:00 

OR SIMULATION CLOCKTIME = 8:30:00 

OR SIMULATION CLOCKTIME = 9:30:00 

OR SIMULATION CLOCKTIME = 10:30:00

OR SIMULATION CLOCKTIME = 11:30:00

OR SIMULATION CLOCKTIME = 12:30:00 

OR SIMULATION CLOCKTIME = 13:30:00  

OR SIMULATION CLOCKTIME = 14:30:00 

OR SIMULATION CLOCKTIME = 15:30:00 

OR SIMULATION CLOCKTIME = 16:30:00  

OR SIMULATION CLOCKTIME = 17:30:00 

OR SIMULATION CLOCKTIME = 18:30:00 

OR SIMULATION CLOCKTIME = 19:30:00 

OR SIMULATION CLOCKTIME = 20:30:00 

OR SIMULATION CLOCKTIME = 21:30:00 

OR SIMULATION CLOCKTIME = 22:30:00

OR SIMULATION CLOCKTIME = 23:30:00

THEN ORIFICE R1 SETTING = 0.90

AND  ORIFICE R2 SETTING = 0.90

AND  ORIFICE R3 SETTING = 0.90

AND  ORIFICE R4 SETTING = 0.90

AND  ORIFICE R5 SETTING = 0.90

AND  ORIFICE R6 SETTING = 0.90

AND  ORIFICE R7 SETTING = 0.90

RULE R1b

; hour setting

IF SIMULATION CLOCKTIME = 0:00:00

OR SIMULATION CLOCKTIME = 1:00:00

OR SIMULATION CLOCKTIME = 2:00:00

OR SIMULATION CLOCKTIME = 3:00:00

OR SIMULATION CLOCKTIME = 4:00:00

OR SIMULATION CLOCKTIME = 5:00:00

OR SIMULATION CLOCKTIME = 6:00:00

OR SIMULATION CLOCKTIME = 7:00:00

OR SIMULATION CLOCKTIME = 8:00:00

OR SIMULATION CLOCKTIME = 9:00:00

OR SIMULATION CLOCKTIME = 10:00:00

OR SIMULATION CLOCKTIME = 11:00:00

OR SIMULATION CLOCKTIME = 12:00:00 

OR SIMULATION CLOCKTIME = 13:00:00

OR SIMULATION CLOCKTIME = 14:00:00 

OR SIMULATION CLOCKTIME = 15:00:00

OR SIMULATION CLOCKTIME = 16:00:00

OR SIMULATION CLOCKTIME = 17:00:00

OR SIMULATION CLOCKTIME = 18:00:00 

OR SIMULATION CLOCKTIME = 19:00:00 

OR SIMULATION CLOCKTIME = 20:00:00 

OR SIMULATION CLOCKTIME = 21:00:00 

OR SIMULATION CLOCKTIME = 22:00:00 

OR SIMULATION CLOCKTIME = 23:00:00

THEN ORIFICE R1 SETTING = 0.5

AND  ORIFICE R2 SETTING = 0.5

AND  ORIFICE R3 SETTING = 0.5

AND  ORIFICE R4 SETTING = 0.5

AND  ORIFICE R5 SETTING = 0.5

AND  ORIFICE R6 SETTING = 0.5

AND  ORIFICE R7 SETTING = 0.5

Reading the Output of Older SWMM 5 versions in Newer SWMM 5 Versions

Subject:   Reading the Output of Older SWMM 5 versions in Newer SWMM 5 Versions

It is very easy to read the output graphs and output text file from older versions of SWMM 5 in newer versions of SWMM 5 as long as the rules are followed:

1.   You need to have the RPT file for the InputFileName or InputFileName.RPT

2.   You need to have the OUT file for the InputFileName or InputFileName.OUT

3.   The File Size for InputFileName.RPT is greater than 0

4.   The Run Status for InputFileName.OUT is true based on the tests in CheckRunStatus

a.       // Starting from end of file, read byte offsets of file's sections

b.       // Read # time periods, error code & file signature

c.       // Read file signature & version number from start of file

d.       // Check if run was completed

e.       // Check if results were saved for 1 or more time periods

f.        // Check if correct version was used

g.       // Check if error messages were generated

Figure 1.   The RPT File or OUT File is not saved unless you 1^st save the Current Simulation Results.

Figure 2.   The binary output file of SWMM 5.0.013 in SWMM 5.0.022

How to see the effect of the Pump Setting in the RTC Rules of InfoSWMM and H20MAP SWMM

Subject:  How to see the effect of the Pump Setting in the RTC Rules of InfoSWMM and H20MAP SWMM

Step 1.   Pump Startup and Shutoff Depth

Depths to turn the Pump On and turn the Pump Off.  In this example, the pump will be off when the Wet Well Depth is less than 2 feet, the Pump will be off between a Wet Well Depth between 2 and 5.75 feet if the Pump is currently Off and the Pump will be On between a Wet Well Depth between 5.75 and 2 feet.

Step 2.   RTC Rule for the Pump Setting when the Wet Well Depth is less than 6.25 feet.  We need to add the AND statement so that the setting is only reset when the Pump is On.   You do not want the pump setting to be reset when the pump should be off.

Result 1:  The Pump Speed Ratio tells you the Pump Setting

Result 2:  RTC Control Rules in the RPT File if you click on Show Control Actions

Result 3:   The depth at the Wet Well and the Flow in the Pump

Result 4:  A mixed graph of the Wet Well Depth and Pump Flow shows the effect of the RTC.

Result 5:  The RTC Rule can also been seen flow to the Pump Curve.