Steady State Flow Analysis in InfoSWMM using a Ramp DWF - Method 1

Subject:  Steady State Flow Analysis in InfoSWMM using a Ramp DWF

Steady State Flow Analysis in InfoSWMM using a Ramp DWF by dickinsonre Subject:  Steady State Flow Analysis in InfoSWMM using a Ramp DWF  This can be easily created using a few steps in InfoSWMM.   Step 1:  Using Scenario Explorer make a cloned Child Scenario and a cloned DWF Set which will be later modified.   Step 2:  Using DB Manager and the BlockEdit tool and increase the mean DWF by a factor of 10, 100 or 1000 to drown out all Wet Wells and cause the pumps to turn on and stay turned on during the simulation in the newly created DWF Set.    Step 3.  Run the batch manager and create two output files – Normal and Steady State for comparison.   Step 4.  You can now compare the two scenario's using Output Manager and the Compare Graph tool.  The Ramped Model should have constant flows in both links and pumps.  It was not necessary to change any of the patterns. Step 5.  The model is still  in balance – the excess DWF Inflow ends up as flooded flow and is listed as Internal Outflow. via Blogger http://www.swmm5.net/2013/08/steady-state-flow-analysis-in-infoswmm_3.html

SWMM 5 Fixed Surface Water Depth Boundary Condition

Subject:  SWMM 5 Fixed Surface Water Depth Boundary Condition

A large difference between SWMM 5 and SWMM 4 is how the Groundwater Aquifer interacts with the drainage network.  In SWMM 4 since the hydrology was simulated in the Runoff Block, the results saved to an interface file and the hydraulics were simulated in the Extran Block it was not possible to have a time step to time step interaction between the Aquifer and the Open Channels.  SWMM 5 has integrated hydrology and hydraulics so it is possible to use either a Fixed Surface Water Depth for each Subcatchment or the Receiving Nodes Node Depth Invert Elevation – the Aquifer Bottom Elevation.  The groundwater thus flows either to a fixed boundary condition as in SWMM 4 or to a time varying boundary condition.

SWMM 5 Threshold Groundwater Elevation

Subject:  SWMM 5 Threshold Groundwater Elevation

A large difference between SWMM 5 and SWMM 4 is how the Groundwater Aquifer interacts with the drainage network.  In SWMM 4 since the hydrology was simulated in the Runoff Block, the results saved to an interface file and the hydraulics were simulated in the Extran Block it was not possible to have a time step to time step interaction between the Aquifer and the Open Channels.  SWMM 5 has integrated hydrology and hydraulics so it is possible to use either a fixed Threshold Groundwater Elevation for each Subcatchment or the Receiving Nodes Invert Elevation.

Aquifers in SWMM 5

Subject:   Aquifers in SWMM 5

Aquifers in SWMM 5 by dickinsonre 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. via Blogger http://www.swmm5.net/2013/08/aquifers-in-swmm-5.html

3 Types of Manholes in SWMM 5 and InfoSWMM

Subject:   3 Types of Manholes in SWMM 5 and InfoSWMM

There are three types of interior manholes in SWMM 5 and InfoSWMM as regards water surface elevations above the Node Rim Elevation:

1^st Excess Water leaves the Node as flooded water if the water surface elevation equals the Rim Elevation (Figure 1 and Gravity Mains),

2^nd Excess Water is  stored in the manhole as pressurized depth if the Node Surcharge Depth is used (Figure 2 and Force Mains)

3^rd Excess Water is stored above the Node Rim Elevation (Surface Ponding and Figure 3)

  

Figure 1.  The default node in SWMM 5 and InfoSWMM has just the Manhole Invert Elevation, the program calculated elevation of the highest connected link and the Node Maximum Depth or Rim Elevation.  If the Water Surface Elevation exceeds the Rim Elevation then any excess flow is lost as flooded flow.

  

Figure 2.  A force main or pressure in SWMM 5 and InfoSWMM has the Manhole Invert Elevation, the program calculated elevation of the highest connected link, the Node Maximum Depth or Rim Elevation and the Node Surcharge Depth.  If the Water Surface Elevation exceeds the Surcharge Elevation then any excess flow is lost as flooded flow but this allows more the links to have more pressure and hence more flow.

  

Figure 3.  The flooded Node option in SWMM 5 and InfoSWMM has just the Manhole Invert Elevation, the program calculated elevation of the highest connected link, the Node Maximum Depth or Rim Elevation and Node Ponding.  If the Water Surface Elevation exceeds the Rim Elevation then any excess flow is NOT lost but stored in the ponded area.  The depth of the ponded area is a function of the ponding area and the excess inflow.  If the water surface elevation goes below the Rim Elevation then the ponded volume flows back into the network.

 

InfoSWMM and Arc GIS Layer Properties for Force Mains and Gravity Mains

Subject:  InfoSWMM and Arc GIS Layer Properties for Force Mains and Gravity Mains

An important advantage of using InfoSWMM is the ability to use all of the Arc GIS layer and programming tools.  For example, you can use the layer properties in the Table of Contents to color and create symbols for the force mains and gravity mains in InfoSWMM.  The Force Main variable (which is a Yes/No parameter) is selected as the field value in the Symbology Tab of Layer Properties which allows you to color and size the link based on the Force Main property of is you do a Layer Join the link property and simulation results.

InfoSWMM Note About Pump Wet Wells

Subject:  Wet Well Maximum depths and Pump Start and Pump Off Depths

  The Wet Well has

·         An invert elevation and

·         A Maximum Depth

The Pumps have

·         Pump On Depth

·         Pump Off Depth

·         Pump Head – Discharge Curve or

·         RTC Rules

The Links have a

·         Invert Elevation into the Wet Well and

·         Invert Elevation into the Downstream Force Main

·         Crown Elevation

Figure 1. Wet Well  Maximum Depth

InfoSWMM or SWMM 5 Basic Runoff and Other Wet Weather Processes

Note:   InfoSWMM  or SWMM 5 Basic Runoff and Other Wet Weather Processes

Figure 1:  Possible Sources of Input flow and Output Losses or Outflow

Figure 2:  Variables and Pathways on a Subcatchment Surface

Figure 3:  Subcatchment Pathways for Rainfall in SWMM 5

Detention Pond Infiltration and Evaporation Losses

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 the infiltration (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.

infiltration_detetention_pond.inp Download this file

Detention Pond Infiltration and Evaporation Losses in SWMM 5 by dickinsonre 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. via Blogger http://www.swmm5.net/2013/08/detention-pond-infiltration-and.html

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.

http://api.ning.com/files/ZtT72Lr8bEOi83U3XrtN9x2vsbK-V--dbjfMZOFEzO4M22pEDeFsuOE5GdQV8Z354OTHNEpjEZwvHPXYyhvbRqPHSxM4DUjv/detetention_pond.INP

InfoSewer Link and Head Calculations for Steady Flow

Note: Steady 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

How the State InfoSewer solution solves for the link flow and node heads by dickinsonre 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: •         1ST 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 2nd pass. •         2nd 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 1st pass in the links and the 2nd 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 1st Pass Link Flow Values. Figure 2. InfoSewer solves for the flows in the links in the 1st pass and the heads at the nodes in the 2nd pass for the Steady State solution. Figure 3.  Pipe Summary Table Shows the Pipe Adjustments based on 2nd Pass Head calculations and the d/D and q/Q values from the 1st Pass Link Flow Calculations. Figure 4:  Two Pass Solution for InfoSewer (1) Flow and (2) Head via Blogger http://www.swmm5.net/2013/08/how-state-infosewer-solution-solves-for.html dic

How to Understand the OUT directory in InfoSWMM and InfoSWMM SA

Note:  How to Understand the OUT directory in InfoSWMM and H2OMAP SWMM

This is how you understand the files in the .OUT directory:

.OUT                         OUT directory of the InfoSWMM project
Scenario                    Location of all Scenario Output Files
Base                         The Base Scenario in this case
JOB                           The temporary output file for inp, out and txt files during the simulation –
                                this  should be cleaned out and copied at the end of the simulation

HYDQUA Header.html   is the left side of the browser page
HYDQUA.html             is the text output file from SWMM 5
HYDQUA.inp               SWMM 5 “like” input file for InfoSWMM
HYDQUA.out               Binary Output File
hydqua.rpt.lid.txt         LID Text Output File
hydqua.rpt.txt             InfoSWMM Text Output   Comprehensive Storm Water Management Model: based on EPA-SWMM 5.0.022

If you have an data abort in some of the older InfoSWMM models the txt and inp files are still in the JOB directory and NOT the BASE directory.  They can still be viewed in the JOB directory using the Notepad icons and searching for the files.

HYDQUA.html,  HYDQUA Header.html and hydqua.rpt.txt together in the browser.

InfoSewer - Minimum Travel Distance

Note:   The minimum travel distance in an InfoSewer or H2OMap Sewer model can be related to the mean link length in the Pipe DB Table.  Here is a table of the Mass balance check for one network versus the minimum travel distance in feet for the default values of network accuracy, minimum time length and maximum number of segments at a report time step of 1 hour.   As you can see making the Minimum Travel equal to the mode of the length histogram yields the best results even for the default model parameters.

Minimum Travel Distance	Mass Balance Check:	Label
1	10.50	(%)
5	3.25	(%)
10	6.25	(%)
20	17.34	(%)
25	7.05	(%)
30	1.38	(%)
40	1.07	(%)
50	1.07	(%)
55	1.05	(%)
58	3.87	(%)
60	3.34	(%)
75	0.55	(%)
80	3.09	(%)
90	11.60	(%)
100	17.20	(%)
200	17.34	(%)
1000	17.34	(%)

InfoSWMM Solution Options in Windows 7

Note:  InfoSWMM Solution Options in Windows 7

1.   32 bit or 64 bit solution engine based on SWMM 5.0.022 selected using the Tools/Preferences/Operation Settings command
2.   Number of dynamic solution threads for parallel processing selected using the Run Manager,
3.   Single or batch runs selected using the Run Manager, and
4.   DLL or the Simulation Task Manager using the Tools/Preferences/Operation Settings command.

You have control over the type of engine, the number of threads, the number of runs and whether the run is started right now or scheduled to run later or in batch mode (Figure 1).

InfoSWMM 11 (for ArcGIS 9, 10) and H20MAP SWMM v10 Updated for the new SWMM 5.0.022 Engine

------------------------------------------------------
EPA SWMM 5 Build 5.0.022 (04/21/11)
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Engine Updates
1. The following fixes and updates were made to the LID module of the code (lid.c):
a. The Drain Delay time for a Rain Barrel LID is now correctly converted internally from hours to seconds.
b. The meaning of the Conductivity property of an LID's Storage layer has been changed. It is now defined as the saturated hydraulic conductivity of the native soil below the layer instead of the conductivity of the layer
itself.
c. Storage layers are now optional for Bio-Retention Cells and Permeable Pavement LIDs by allowing the layer height to be zero. One should still enter a non-zero conductivity for the layer if infiltration into native soil is allowed.
d. If the top width of the overland flow surface for an LID is zero then any excess water above the surface storage depth simply spills out instantaneously.
e. The calculation of infiltration in a Vegetative Swale was corrected so that a swale with vertical sides will produce the same results as a fully pervious subcatchment with the same dimensions, roughness, and slope.
f. The water initially stored in all LID units is now reported in the Status Report's Runoff Continuity table.
g. Error messages are now generated if the surface layer vegetation volume fraction is less than 1, if the area of all LIDs in a subcatchment is greater than the total area or if the total capture area of all LIDs is greater than the subcatchment's total impervious area.
2. Missing values for accumulation periods within an NWS rain file are now processed correctly. See rain.c.
3. A new error message (318) is now generated if a user-prepared rainfall file has its dates out of sequence.
4. Evaporation during wet time periods was including rainfall and run-on as moisture available for evaporation when it should only be the current ponded depth. See subcatch.c.
5. Curve Number infiltration was modified to use only direct precipitation, not including runon or internally routed flow, to compute an infiltration rate. See infil.h, infil.c, subcatch.c and lid.c.
6. A new error message (110) is now generated if the ground elevation of a subcatchment is less than the initial water table elevation of its groundwater aquifer. See gwater.c, err.h, and err.c.
7. A check was added to the tailwater term of the groundwater flow equation to insure that the term is zero when no tailwater depth exists. See gwater.c.
8. Checks were added to the solution of the governing groundwater mass balance equations to catch conditions where the lower zone depth is greater than the total depth or when the upper zone moisture content is greater than the porosity. See gwater.c.
9. A divide by zero error no longer occurs when computing the hydraulic radius of an empty Filled Circular pipe whose filled depth is zero. A similar error for the hydraulic radius of an empty trapezoidal channel whose bottom width was zero was also eliminated. See xsect.c.
10. The critical or normal depth adjustment made for a conduit is no longer allowed to set the depth to zero -- some small depth level is always maintained. See dynwave.c.
11. The Pump Summary Report was expanded to include number of start-ups, minimum flow, and time off both the low and high ends of the pump curve. See objects.h, link.c, stats.c, and statsrpt.c.
12. When the setting of an orifice or weir was changed to 0 (to completely block flow) the flow depth in the element wasn't being set to 0. This was only a reporting error and had no effect on the flow routing calculations. See link.c.
13. The Node Surcharge Summary in the Status Report did not report a ponded node as being surcharged. This was only a reporting error and had no effect on the flow routing calculations. See stats.c.