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

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.

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

The Importance of Viewing Results at the Proper Time Scale

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.

The Importance of Viewing Results at the Proper Time Scale in SWMM5 and InfoSWMM Models by dickinsonre 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. via Blogger http://www.swmm5.net/2013/08/the-importance-of-viewing-results-at.html

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

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

An Example of the Importance of the Term DQ4 in the SWMM 5 St Venant Solution by dickinsonre 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.   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 not continuity error as the term dq4 keeps the water in the link  in balance. via Blogger http://www.swmm5.net/2013/08/an-example-of-importance-of-term-dq4-in.html

ArcToolBox GIF in InfoSewer and InfoSWMM

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

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

Use the SWMM 5 Scatter Graph to show the Pump Curve used during the Simulation by dickinsonre 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.   via Blogger http://www.swmm5.net/2013/08/use-swmm-5-scatter-graph-to-show-pump.html

From SciAM - Why Plants are important to River Formation

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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How to Import the SWMM 5 Report File as a Layer in infoSWMM

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

How to Import the SWMM 5 Report File as a Layer in infoSWMM by dickinsonre 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 Rangeshould 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

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

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

How to Approximate a Timer in the RTC Rules of SWMM 5 by dickinsonre 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. via Blogger http://www.swmm5.net/2013/08/how-to-approximate-timer-in-rtc-rules.html

gate_timer.INP Download this file

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

Philadelphia and Green Infrastructure

Changing the rules in the middle of the game: Philadelphia's 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

Example SWMM 5 Model for Activated Sludge

Note:   Example SWMM 5 Model for Activated Sludge

Example SWMM 5 Model for Activated Slude by dickinsonre Note:   Example SWMM 5 Model for Activated Sludge Here is one example of how to model an activated sludge tank.  The image is Wikipedia (http://en.wikipedia.org/wiki/Activated_sludge)  and is the watermark background in the SWMM 5 GUI.  There is 100 lps inflow, 20 percent recycle and 10 percent sludge drawoff.   You can adjust the amount of recycle and sludge altering the pump type 2 flows or if you want to increase the inflows – add more flow in the RawWater inflow node. via Blogger http://www.swmm5.net/2013/08/example-swmm-5-model-for-activated-slude.html

Three Flow Divider Link Example in SWMM 5

Subject:  Three Flow Divider Link Example in SWMM 5

Three Flow Divider Link Example in SWMM 5 by dickinsonre Subject:  Three Flow Divider Link Example in SWMM 5  You can have more than 2 downstream OUTLET Type links in the SWMM 5 dynamic wave solution.  Each link, Under5, Over5 and ReturnFlow is an OUTLET Link with a rating curve depth/flow table.  Depending on the depth in the storage node DIVIDER, the flow is computed from the table for links Under5, Over5 and Return Flow.    via Blogger http://www.swmm5.net/2013/08/three-flow-divider-link-example-in-swmm.html

Output Statstics Manager to find negative flows in InfoSWMM

Subject:  Output Statstics Manager to find negative flows in InfoSWMM

Output Statstics Manager to find negative flows in InfoSWMM by dickinsonre ubject:  Output Statstics Manager to find negative flows in InfoSWMM Output Statstics Manager to find negative flows with these parameters: 1.       Pipe Features 2.       Use a Domain with your force mains 3.       Select Flow 4.       Event Dependent 5.       Total – NOT Mean or Peak to  find the negative and positive flows 6.       Large NEGATIVE Flow Threshold 7.       Large NEGATIVE Volume Threshold 8.       Zero for Interevent Time to pick up all values 9.       You will get a table that shows you the minimun flows, and a histogram of the flows   via Blogger http://www.swmm5.net/2013/08/output-statstics-manager-to-find.html

  

Flow Dividers in SWMM 5 Dynamic Routing

Note:  Flow Dividers in SWMM 5 Dynamic Routing

Flow Dividers in SWMM 5 Dynamic Routing by dickinsonre 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 via Blogger http://www.swmm5.net/2013/08/flow-dividers-in-swmm-5-dynamic-routing.html

Keep and Dampen options and their effect on the four main terms of the St Venant equation

Note:  The Keep and Dampen options and their effect on the four main terms of the St Venant equation. 

The Keep and Dampen options and their effect on the four main terms of the St Venant equation in SWMM5 by dickinsonre Note:  The Keep and Dampen options and their effect on the four main terms of the St Venant equation.  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 dq3 term in dynamic.c uses the current midpoint area (a function of the midpoint depth), the sigma factor and the midpoint velocity. dq3 = 2 * Velocity * ( Amid(current iteration) – Amid (last time step) * Sigma dq1 = Time Step * RoughFactor / Rwtd^1.333 * |Velocity| The weighted area (Awtd) is used in the dq2 term of the St. Venant equation: dq2 = Time Step * Awtd * (Head Downstream – Head Upstream) / Link Length or dq2 = Time Step * Awtd * (Head Downstream – Head Upstream) / Link Length Normally, dq1 (Friction Loss / Maroon in the Graph) balances dq2 (Water Surface Slope Term or Green in the Graph) but often for links with a large difference between upstream and  downstream depths dq4 (Red in the Graph) can have a significant value.  If dq4 or dq3 are important then the depth of water to increases to pass the same flow using the Keep option over the Ignore.   If you have a link with a Froude number near or over 1.0 (Supercritical) then using Keep or Dampen  for the Options may result in depth differences.   The effect of Keep is to increase the "loss" terms in the St VenantEquation.   The effect of Dampen and Ignore is to decrease the sum of the "loss" terms in the St. Venant Solution and lower the simulated depth. via Blogger http://www.swmm5.net/2013/08/the-keep-and-dampen-options-and-their.html