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SWMM 5 Water Quality Example Files

SWMM 5 Water Quality Example Files

File Name Description
RUNOFF3_SW5.INP STEVEN''S AVENUE DRAINAGE DISTRICT LANCASTER PA
RUNOFF20_SW5.INP Runoff Example # 20 - PCSWMM 3.2 EXERCISE 5
RUNOFF21_SW5.INP SUSPENDED SOLIDS AND BOD POLLUTOGRAPH SIMULATION
RUNOFF22_SW5.INP RUNOFF EXAMPLE # 22 - SIMULATION OF EROSION
RUNOFF23_SW5.INP A wide parabolic channel between 301 and 401
RUNOFF31_SW5.INP PCSWMM 3.2 EXERCISE 5 - Runoff example 31
RUNOFF41_SW5.INP Runoff example 41 - Input of constant groundwater quality
RUNOFF42_SW5.INP Precipitation quality only
RUNOFF43_SW5.INP BROWARD COUNTY Multi FAMILY SITE - Runoff example # 43
RUNOFF44_SW5.INP HDR STORM USGS STORM # 3 May 5 1977
RUNOFF45_SW5.INP BROWARD COUNTY Multi FAMILY SITE
RUNOFF46_SW5.INP BROWARD COUNTY Multi FAMILY SITE
RUNOFF47_SW5.INP BROWARD COUNTY Multi FAMILY SITE - Runoff example # 47

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SWMM 5 Interface Guide Tips for C Compilers

SWMM 5 Interface Guide Tips

SWMM 5 has a Interfacing guide on http://www.epa.gov/nrmrl/wswrd/wq/models/swmm/#Downloads for creating a VB, Delphi or command line C program to both run and printout some of the output file results from SWMM 5. The readme file is self explanatory in the file http://www.epa.gov/nrmrl/wswrd/wq/models/swmm/swmm5_iface.zip but here are a few tips for those of you who want to compile the InterFaceGuide C code in a Executable file for Windows.
1. The first step is to make a new console program in Visual Studio

2. The second step is to add the files swmm5.h, swmm5_iface.h, swmm5_iface.c, test.c to the project header and source files.
3. Next add the file swmm5.lib as an additional dependency along with the directory name.
4. If you want to save the .out and .rpt files then you must comment out the remove statements at the end of test.c

5. You need to make a batch file to both run and save the input and output files from SWMM 5,
6. The file swmm5.dll must be in the same directory as the created interface executable file,
7. It will help you see the intermediate output if you add a pause statement in the batch file to hold the fprintf statements on the screen for you to view.

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Transect data processing in SWMM

Hello,

My model includes a canal and I am using a transect to represent the canal. One of the typical sections is shown in the  figure. I uses the actual elevation data for the transect cross section and hence some coordinate values are negative.

1. The profile view does not show the negative portion. Is there any way I can see the full depth profile view? will there be any problem in SWMM internal calculation if I use negative value ( as shown in the figure).

2. From the transect sections, does SWMM automatically calculate the slope ( using the lowest coordinates) or it uses the section only to calculate area and wetted perimeter. I am asking this because if it considers lowest coordinates than there will be problem from double counting if I input slope through offsets.

3. I will use stage data at outfall. what is the datum SWMM considers for stage data depths given?

Thank you in anticipation.

Regards

Shams

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SWMM 5 Precipitation Options


Subject:  SWMM 5 Precipitation Options

You can have design storms, monitored storms of any length of the time from minutes to centuries, use intensity, volume or cumulative precipitation, use both rainfall and snowfall in the same rain gage depending on temperature, use both time series or external files for the rain gage and have unlimited rain gages with the limitation of one rain gage per subcatchment . 


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Subject:  Force Main Friction Loss in InfoSWMM and the Transition from Partial to Full Flow

[as the full pipe friction loss method (see Figure 1 for the internal definition of full flow).   A function called ForceMain in InfoSWMM whose purpose is to compute the Darcy-Weisbach friction factor for a force main using the Swamee and Jain approximation to the Colebrook-White equation .  No matter which method you use for full flow the  program will use Manning’s equation to calculate the loss in the link when the link is not full (see Figure 2 for the equations used for calculating the friction loss – variable dq1 in the St Venant equation for InfoSWMM).   The regions for the different friction loss equations are shown in Figure 3.     

There is no slot in InfoSWMM for the full pipe flow as a surcharged node in InfoSWMM uses this point iteration equation (Figure 4):

 

dY/dt = dQ / The sum of the Connecting Link values of  dQ/dH

 

where Y is the depth in the node, dt is the time step, H is the head across the link (downstream – upstream), dQ is the net inflow into the node and dQ/dH is the derivative with respect to H of the link  St Venant equation.  If you are trying to calibrate the surcharged node depth, the main calibration variables are the time step and the link  roughness:

 

1.   Mannings’s N

2.   Hazen-Williams or

3.   Darcy-Weisbach

 

The link roughness is part of the term dq1 in the St Venant solution and the other loss terms are included in the term dq5.  You can adjust the roughness of the surcharged link  to affect the node surcharge depth.   The point iteration continues until the sum of the flow in the node is zero – basically the new depth in the node either increases or decreases the friction loss in the force main so that net flow at the node is zero.  This is why it is important to use the right time step to ensure that the net flow is zero when the pumps turn on and off.

  

Figure 1.  How the full pipe condition is defined in InfoSWMM - both ends have to be full

Figure 2:  Friction equations used in SWMM 5 for a Force Main. 

 

Figure 3:  Regions of Friction loss equations in SWMM 5.


Figure 4.  The Node Surcharge Equation is a function of the net inflow and the sum of the term dQ/dH in all connecting links. Generally, as you increase the roughness the value of dQ/dH increases and the denominator of the term dY/dt = dQ/dQdH increases.

You can model Force Mains in SWMM 5 using either Darcy Weisbach or Hazen Williams as the full pipe friction loss method (see Figure 1 for the internal defintion of full flow).   No matter which method you use for full flow the  program will use Manning’s equation to calculate the loss in the link when the link is not full (see Figure 2 for the equations used for calculating the friction loss – variable dq1 in SWMM 5).  Force Main Friction Loss in SWMM 5.

Figure 1.  How the full pipe condition is defined in SWMM 5

 

Figure 2:  Friction equations used in SWMM 5 for a Force Main.

Figure 3:  Regions of Friction loss equations in SWMM 5.

 

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Example Groundwater Model in SWMM 5

Subject:   Example Groundwater Model in SWMM 5 

The attached model shows three ways in which the groundwater model of the SWMM 5 subcatchments interact with the node depths of the hydraulic network.  The hydraulic network interaction can be either: 

1.       At a fixed water surface elevation,

2.       At a time varying water surface elevation based on the inflow and geometry of the node and

3.       At a threshold node water surface elevation. 

GW_INTERACTION.inp Download this file

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Subject:   Example FM SWMM 5 model with and without Surcharge Depth

 

You need to use the surcharge depth for a Force Main in SWMM 5 to allow the engine to find the right point on the pump curve and pump up the rising main.  If you do not use a surcharge depth then the flow MAY be very small in the rising main due to a small head difference.  Of course the flow in the force main depends on the pump curve you have entered but having the right downstream head of depth for the link matter as well.  The attached model was created in SWMM 5.0.022 

 

fm_storage.inp Download this file

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Subject:  The Pump summary table of SWMM5.0.022 and the Percent Time off Columns

The pump summary table at the end of the SWMM 5 report file has two columns for the time off the pump curve BUT the two columns are only informative if the pump is a type 4 pump.  If the pump type is 1, 2 or 3 then the low column is always 0 and when the volume, depth or head is either below the lowest point in the point curve or above the highest point in the pump curve the pump summary table lists the time off either low or high in the High column.

xMin is  the 1st point in the pump curve for either volume, depth, head or depth, respectively for pump1, pump2, pump3 and pump4 type pumps

xMax is the last point in the pump curve for either volume, depth, head or depth, respectively for pump1, pump2, pump3 and pump4 type pumps

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Dual Drainage in SWMM 5

Subject:  Dual Drainage in SWMM 5

 

The purpose of the Dual Drainage tool in InfoSWMM is to create a major or street drainage network on top of an existing pipe or what is called the minor network in  dual drainage.  The created major network has a node (sometimes called the inlet node) on top of the existing minor network node connected by two  OUTLET links.  One outlet link takes the flow from the street and  passes it to the minor network node, the second outlet link  takes the surcharged minor network flow and passes it to the major network or street – the direction of flow is important (Figure 1).  The general purpose of the Captured OUTLET is to  use a head or depth equation to separate the street incoming  flow into captured flow and bypass flow

 

Figure 1.  Dual Drainage in General

Figure 2.  How it looks in SWMM 5 with node, outlet and conduit elements.

 

Dual Drainage in SWMM 5

Subject:  Dual Drainage in SWMM 5

The purpose of the Dual Drainage tool in InfoSWMM is to create a major or street drainage network on top of an existing pipe or what is called the minor network in  dual drainage.  The created major network has a node (sometimes called the inlet node) on top of the existing minor network node connected by two  OUTLET links.  One outlet link takes the flow from the street and  passes it to the minor network node, the second outlet link  takes the surcharged minor network flow and passes it to the major network or street – the direction of flow is important (Figure 1).  The general purpose of the Captured OUTLET is to  use a head or depth equation to separate the street incoming  flow into captured flow and bypass flow

Figure 1.  Dual Drainage in General

Figure 2.  How it looks in SWMM 5 with node, outlet and conduit elements.

 

Topic:  Example Dual Drainage SWMM 5 model

 

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Subject:   How to Make a Smaller Model out of a Large Model in InfoSWMM

InfoSWMM and H2OMAP SWMM will export only those ACTIVE elements to SWMM 5 as defined by the Facility Manager. 

You can use the feature to make smaller SWMM 5 models and then reimport the exported smaller SWMM 5 model back into a H2OMAP SWMM or InfoSWMM scenario.

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Maximum Surcharge Height Over Crown Explanation

Note:   Maximum Surcharge Height Over Crown Explanation 

Here is an example of how the Maximum Surcharge Height over the Node Crown is calculated.     Consider a manhole with an invert of 10 feet,  one incoming pipe (Pipe A), one outgoing pipe (Pipe B), both pipes with a diameter of 2 feet, but the invert  of Pipe A is 10 feet and the invert of Pipe B is 11 feet.  What is the Maximum Surcharge height if the HGL at the node is 17 feet?     

HGL at Node ---- 17 feet

                                                                                                           Maximum Surcharge Height Over Crown is 4 feet

                                                                                                           Node Crown --- 13 feet Pipe B Crown --- 13 feet

Pipe A Crown --- 12 feet

Pipe B Invert --- 11 feet

Pipe A Invert --- 1o feet MH Invert --- 10 feet

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

 

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Subject:   The Importance of Viewing Results at the Proper Time Scale
 
In SWMM 5 when you are simulating rapidly changing flow – such as pump flows – it is important to  remember that you are only seeing the results of the simulation at your selected report time step.  Here is an example model with the same number of pump starts for all three simulations (318), the same  average time step during the simulation (10 seconds) but different report time steps.  The conception of the pump starts is totally different visually depending on the selected report time steps.  You should always compare the starts using the pump graphs and the pump summary table.    The percent utilized and the number of pump start ups tells you  the mean pump start length or in this case 153 seconds or 45.1 percent of 30 hours divided by 318 pump starts.
 
 

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Subject:   An Example of the Importance of the Term DQ4 in the SWMM 5 St Venant Solution

The four terms are are used in the new flow for a time step of Qnew:

Qnew = (Qold – dq2 + dq3 + dq4) / ( 1 + dq1)

when the force main or gravity main is full dq3 and dq4 are zero and  Qnew = (Qold – dq2) / ( 1 + dq1)

The dq4 term in dynamic.c uses the area upstream (a1) and area downstream (a2), the midpoint velocity, the sigma factor (a function of the link Froude number), the link length and the time step or

dq4 = Time Step * Velocity * Velocity * (a2 – a1) / Link Length * Sigma

where Sigma is a function of the Froude Number and the Keep, Dampen and Ignore Inertial Term Options.  Keep sets Sigma to 1 always and Dampen set Sigma based on the Froude number, Ignore sets Sigma to 0 all  of the time during the simulation.

The value of dq4 increases when there is a significant difference in the cross sectional  area of the downstream end of the link and the upstream end of the link.  In this  example, the downstream storage node causes a backflow in the link (Figure 1).   The flow may look unstable in the link  flow time series but the change in flow is simply due to the water sloshing back and forth.  There is no continuity error as the term dq4 keeps the water in the link  in balance (Figure 2).

Gickr
Figure 1.  GIF of Water Surface Showing the effect of the term dq4
2012-02-05_2159
Figure 2.  Time Series of Flow - the Link has Mass Balance due to the term dq4

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Subject:  Use the SWMM 5 Scatter Graph to show the Pump Curve used during the Simulation

 

You can use a scatter graph to show the relationship between the pump during the simulation and the Storage Depth.   If the pump is on the curve based on the pump summary table then the scatter graph should  look like the pump curve.  The pump summary table in the  SWMM 5 RPT also shows you the time off the pump curve low and high.

 

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Thanks to Plants, We Will Never Find a Planet Like Earth


Earth's flora is responsible for the glaciers and rivers that have created this planet's distinctive landscape

Perhaps even more surprisingly, vascular plants formed the kinds of rivers we see around us today, according to another article by Martin Gibling of Dalhousie University in Nova Scotia and Neil Davies of the University of Ghent in Belgium, who analyzed sediment deposition going back hundreds of millions of years. Before the era of plants, water ran over Earth's landmasses in broad sheets, with no defined courses. Only when enough vegetation grew to break down rock into minerals and mud, and then hold that mud in place, did river banks form and begin to channel the water. The channeling led to periodic flooding that deposited sediment over broad areas, building up rich soil. The soil allowed trees to take root. Their woody debris fell into the rivers, creating logjams that rapidly created new channels and caused even more flooding, setting up a feedback loop that eventually supported forests and fertile plains.

 

"Sedimentary rocks, before plants, contained almost no mud," explains Gibling, a professor of Earth science at Dalhousie. "But after plants developed, the mud content increased dramatically. Muddy landscapes expanded greatly. A new kind of eco-space was created that wasn't there before."

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Subject:  How to Import the SWMM 5 Report File as a Layer in InfoSWMM

 The idea of this blog of note is to show how one may extract information from the SWMM 5 or InfoSWMM RPT file and import the Excel  File as a feature in InfoSWMM.  This blog has an example Excel file to illustrate the linkage. The steps are: 

Step 1:  Copy the whole row  from Conduit Summary from the InfoSWMM Browser

Step 2:  Add the two columns length and  slope from the Link Summary Table and the InfoSWMM Browser

Step 3:  You need a few calculations based on the table values from SWMM 5 to estimate the CFL  time steps in the .

Step 4:   Add the Excel Spreadsheet as a layer in InfoSWMM – the Named Range should be added to insure valid numbers and not Nulls after the join

Step 5:  You can now plot the CFL Time Step for the Links using the Layer Properties command in Arc Map

 

Step 1:  Copy the whole row  from Conduit Summary

 

 

 

Step 2:  Add the two columns length and  slope from the Link Summary Table

 

 

 

Step 3:  You need a few calculations based on the table values from SWMM 5 to estimate the CFL  time steps.

 

The CFL Step      = Length / (Full  Velocity + (Gravity * Full Depth)^0.5)

Full Velocity        = Full Flow / Full  Area

 

You also need to create a Name A Range for you data so that the data does not show up as Nulls

 

 

 

 

Step 4:  Add the Excel Spreadsheet as a layer in InfoSWMM – the Named Range should be added

 

 

 

 

Step 4:  Join the Excel  Table to the InfoSWMM Conduit Feature Layer

 

 

 

Step 5:  You can now plot the CFL Time Step for the Links using the Layer Properties command in Arc Map 

 

 

 

 

 

swmm5_summary_table.xlsx Download this file

How to Import the SWMM 5 Report File as a Layer in infoSWMM.docx Download this file

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Subject:   How to Approximate a Timer in the RTC Rules of SWMM 5

 

SWMM 5 does not have a explicit timer in its Real Time Control (RTC) rules but you can approximate it by using a Control Curve as in the attached example model.  The Control Curve will modify the setting of the Weir by the Inflow to the Storage node.  You can have normal weir flow settings based on the invert elevation of the weir and the Surface node water surface elevation but in addition you can control the weir setting by:

 

1.   Closing the weir when the inflow is low,

2.   Closing the weir by staggered Storage node depth,

3.   Opening the weir gradually when the inflow increases

4.   Closing the weir by a combination of Node Depth IF statements and Control Curve rules

 

For example, you can have the Weir Setting controlled the Node Depth,  Link Inflow and Node Inflow  simultaneously approximately with the depth and the inflow parameters closing the weir by proxy instead of by time since the closing.

 

Image004

gate_timer.INP Download this file

How to Approximate a Timer in the RTC Rules of SWMM 5.docx Download this file

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Philadelphia and Green Infrastructure

Category: Water
Posted on: January 18, 2012 4:14 PM, by
 Liz Borkowski


Philadelphia and Green Infrastructure


Aging US water infrastructure has meant more leaks, flooded basements, and massive sinkholes in cities across the US. Fixing the water and sewer systems in need of repair will take billions of dollars, and it's hard to find that kind of money in the budget these days.

Saqib Rahim reports for ClimateWire on Philadelphia's decision to use "green infrastructure" rather than building a larger pipe system to handle the water that's dumped on the city during severe storms. The combination of more intense storms and more paved area is a problem: Impervious surfaces like roads, sidewalks, and parking lots can't absorb rainfall, so it ends up in the city's stormwater collection system -- which, in many older cities, is combined with the sewage system. When these combined systems are overwhelmed by heavy rainfall, the result is often that a rainfall-and-sewage mixture gets discharged into a local waterway. (Read more about this problem here.) Rahim explains Philadelphia's solution to this problem:

Instead of building an even larger pipe system to address the issue, [Water Department Commissioner Howard] Neukrug pitched the most aggressive "green infrastructure" plan in the country. Through increased vegetation, rain barrels, sponge-like roads and other measures, the city would try to absorb more water where it fell. The ground would filter out pollutants, reduce strain on the pipelines and make the city a more attractive place.

Neukrug tells Rahim that the green infrastructure solution will cost Philadelphia $2 billion, compared to $8 billion to $10 billion for larger underground tunnels. But the part of the city's plan that's currently causing a controversy is what water customers will pay. They'll now be charged not just for the water they use, but for their contributions to stormwater problems -- that is, sites with a lot of impervious surfaces will pay more.

The average household will see an average bill rise from approximately $60 to around $63.50, Rahim reports. For some large businesses, though, costs could rise significantly over the next few years -- and 100 of these businesses have hired a lobbyist and met with the Water Department to oppose implementation of the new billing practices.

I can understand why these businesses are upset. When they invest and plan for their businesses' futures, they assume the rules will stay the same. Their extensive impervious surfaces are causing problems for public health, but they might not have realized that their decisions about what to pave were raising costs for the city's residents (and everyone else affected when its sewage ended up in local waterways).

Changing the rules isn't ideal, but it's the best solution if the current rules create incentives for behavior that harms public health. If this country had never changed the rules to make businesses start bearing more of the cost for problems they cause the general public (externalities, in economic language), we'd still have rivers so polluted that they catch fire. Governments can ease the pain by providing grants or low-interest loans to help businesses and individuals invest in greener setups -- and, Rahim reports, Philadelphia is offering loans to businesses that want to green their facilities. Increases in bills will also be capped at 10% or $100 per month.

Such an approach could also be used to address other public health issues like CO2 emissions -- but so far, opposition to a carbon tax has been stronger than support. In the meantime, I'll be watching Philadelphia's effort and hoping it succeeds with a green solution to water infrastructure challenges.

Source:  http://scienceblogs.com/thepumphandle/2012/01/changing_the_rules_in_the_midd.php#more

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Flow Dividers in SWMM 5 Dynamic Routing

Note:  Flow Dividers in SWMM 5 Dynamic Routing

You can  have flow dividers in SWMM 5 dynamic routing by using Storage Nodes for the dividers, OUTLET links for the downstream links and minimizing downstream HGL effects. The needed components are:

1.   A Storage Node for the divider node as a OUTLET Link does not have a Surface Area,

2.   Two or More OUTLET Links as the downstream diversion and cutoff links,

3.   Two or More Rating Curves to divide the flow up based on either depth or head,

4.   Pumps, Outfalls or Steep Sloped Links Downstream of the diversion and cutoff links to minimize downstream HGL  effects

Image002

dividers_in_dynamic_wave.inp Download this file


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