SWMM 5 Inlet Control Culvert Equations

Subject:   SWMM 5 Inlet Control Culvert Equations

SWMM 5 Inlet Control Culvert Equations by dickinsonre 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. via Blogger http://www.swmm5.net/2013/08/swmm-5-inlet-control-culvert-equations.html

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

SWMM 5 Culvert Data from FHWA, HDS No. 5, Hydraulic Design of Highway Culverts, 1985 by dickinsonre 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. via Blogger http://www.swmm5.net/2013/08/swmm-5-culvert-data-from-fhwa-hds-no-5.html

Understanding Your Model Output in H2oMAP SWMM and InfoSWMM

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

Three Hidden Secrets to Speeding up your SWMM 5, H2OMAP SWMM or InfoSWMM Model by dickinsonre    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  via Blogger http://www.swmm5.net/2013/08/three-hidden-secrets-to-speeding-up.html

Elevation Interpolation from a Contour in H2OMAP SWMM

Subject:  Elevation Interpolation from a Contour in H2OMAP SWMM

Elevation Interpolation from a Contour in H2OMAP SWMM by dickinsonre 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.  via Blogger http://www.swmm5.net/2013/08/elevation-interpolation-from-contour-in.html

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 of InfoSWMM by dickinsonre 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.   via Blogger http://www.swmm5.net/2013/08/how-to-see-what-you-have-in-various.html

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.

Variable Time Step in SWMM 5

v  The goal of the link lengthening in SWMM 5 it to meet the CFL time step condition for the full link depth and full link velocity at the chosen lengthening time step.  If the link does not meet the CFL condition then this means the time step needed is smaller than your selected lengthening time step.  SWMM 5 will make an hydraulically equivalent longer link with a smaller roughness but the same full flow velocity as the shorter link.

v  If you are running a simulation in which all of the pipes are exactly full – no surcharge in any pipe – and the variable time step then there would be no need for SWMM 5 to use anything other than the minimum of the routing or lengthening time step.  However, since most real networks have a mixture of partial flow, surcharged flow and pressure flow, the actual time step depth, velocity/Froude Number is different than the assumed full depth and full flow velocity.  For example, the depth can be higher at one end of the pipe and the velocity higher than full flow velocity due to the water surface slope being higher than the bed slope.  The only way SWMM 5 can now satisfy the CFL time step condition since the modified length is fixed is to lower the variable time step.

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

Reading the Output of Older SWMM 5 versions in Newer SWMM 5 Versions by dickinsonre 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 1st save the Current Simulation Results. Figure 2.   The binary output file of SWMM 5.0.013 in SWMM 5.0.022 via Blogger http://www.swmm5.net/2013/08/reading-output-of-older-swmm-5-versions.html

All Possible Culverts Example Model in SWMM5

Note:  Attached is an example SWMM 5 model that has all 57 culvert types possible in SWMM 5 in one model.  The culverts are 57 small individual networks consisting of an inflow node, an upstream open channel, upstream node for the culvert, culvert link with culvert code, downstream node of the culvert, downstream open channel and finally an outfall node.  The culvert code and the shape of the culvert determine which FHWA equation is used to determine the flow INTO the Culvert during the simulation:

 1.   The flow from the St Venant Equation or
2.   The flow from the FHWA equation
 The minimum flow is used by the program. 

all_culverts.inp Download this file

All Possible Culverts Example Model in SWMM5 by dickinsonre Note:  Attached is an example SWMM 5 model that has all 57 culvert types possible in SWMM 5 in one model.  The culverts are 57 small individual networks consisting of an inflow node, an upstream open channel, upstream node for the culvert, culvert link with culvert code, downstream node of the culvert, downstream open channel and finally an outfall node.  The culvert code and the shape of the culvert determine which FHWA equation is used to determine the flow INTO the Culvert during the simulation: 1.   The flow from the St Venant Equation or 2.   The flow from the FHWA equation The minimum flow is used by the program.  via Blogger http://www.swmm5.net/2013/08/all-possible-culverts-example-model-in.html

How Dry Weather Flow is Used in InfoSWMM at a Node

Note:   How Dry Weather Flow is Used in InfoSWMM at a Node

How Dry Weather Flow is Used in InfoSWMM at a Node by dickinsonre Note:   How Dry Weather Flow is Used in InfoSWMM at a Node  There are four components to the Dry Weather Flow (DWF) in InfoSWMM:  1.       The mean flow in user units at the node, 2.      The DWF Allocation Code – if you are using the DWF Allocator 3.      The Pattern for Weekday, Weekend etc for the mean flow.  The data is entered or entered for you in the Node Inflow Icon or the Operations Tab of the Attribute Browser  Node Inflow Icon and Associated Data  Operation Tab Patterns  You can also make global changes to your DWF using the Node DWF DB Table Under Extended Element Modeling Data   via Blogger http://www.swmm5.net/2013/08/how-dry-weather-flow-is-used-in.html

SWMM5 Weir Rules, Head Calculations and Weir HGL Plots

Note:  SWMM5 Weir Rules and Head Calculations

This note attempts to explain both how the head upstream and the head downstream of a weir in SWMM 5 is calculated compared to the weir crest elevation and also to explain how the weir is presented in the HGL plot of SWMm 5.  There has been confusion in the past concering how the weir is shown compared to the actual weir calculations.  The node head is calculated obviously at both ends of the weir but the head over the weir is always based on H1-Crest or H2-Crest (Figure 1) and hence the weir should look flat – to the weir the downstream head is important but NOT the downstream node invert so the weir really is flat and should look flat in the HGL Profile across the weir (Figure 2).    The crest elevation is always relative to the upstream node invert elevation NOT the downstream node invert elevaation

Figure 1.  How the Head across a Weir is calculated in SWMM 5

Figure 2.   HGL Profile across a Weir in SWMM 5.0.022.  The black line should be shown flat.

Weir and Orifice Flow Equations for a Weir in SWMM 5 by dickinsonre Note:  Weir and Orifice Flow Equations for a Weir in SWMM 5 If you use a weir in SWMM 5 then two flow equations are used 1.       The weir uses the weir flow equation when the head at the weir is between the invert elevation of the weir and the crown of the weir and 2.      An orifice equation when the head is above the weir crown or the weir is submerged. via Blogger http://www.swmm5.net/2013/08/weir-and-orifice-flow-equations-for.html

Time Step Approximation based on Link Lengths

Note:  A rough approximation of the time step you need for an InfoSWMM or H2OMAP SWMM model can be found by finding the mean link length using the field statistics tool for the length in the Conduit DB Table and then estimating the time step from the mean length, mean full depth velocity and mean full depth wave celerity.

The time step actually used during the simulation is related to this velocity and the safety adjustment factor.  The larger the safety adjustment factor the larger the mean time step listed in the Routing Time Step Suggestion.

Stream Names in the USA

Stream Names in the USA from http://derekwatkins.wordpress.com/2011/07/25/generic-stream-terms/

Generic place names (or toponyms) such as Cumberland Gap or Mount Rainier provide general categorical descriptions of a geographic feature, in contrast to specific toponyms, which provide a unique identifier: Lake Huron. This map taps into the place names contained in the USGS National Hydrography Dataset to show how the generic names of streams vary across the lower 48. Creeksand rivers are symbolized in gray due to their ubiquity (although the etymology behind the American use of creek is interesting), while bright colors symbolize other popular toponyms.

Lite-Brite aesthetic notwithstanding, I like this map because it illustrates the range of cultural and environmental factors that affect how we label and interact with the world. Lime green bayous follow historical French settlement patterns along the Gulf Coast and up Louisiana streams. The distribution of the Dutch-derived term kill (dark blue) in New York echoes the colonial settlement of “New Netherland” (as well as furnishing half of a specific toponym to the Catskill Mountains). Similarly, the spanish-derived terms rio, arroyo, and cañada (orange hues) trace the early advances of conquistadors into present-day northern New Mexico, an area that still retains some unique cultural traits. Washes in the southwest reflect the intermittent rainfall of the region, while streams named swamps (desaturated green) along the Atlantic seaboard highlight where the coastal plain meets the Appalachian Piedmont at the fall line.