Using the Link Geometry to Divide the Flow

You can use the geometry of the connecting pipes to divide the flow instead of flow divider in the dynamic wave solution of SWMM 5. You can try to do the same using an Outlet link but the method of using two outlets is sometimes very unstable and requires a small time step just to lower the continuity error. I used two flat rectangular links with the same maximum depth and but different width values (Figure 1). The flow was split based on the value of Q full for the link (which you can see in the text output file (Figure 2).

Figure 1. Link Geometry



Figure 2. Flow Division from a inflow of 10 mgd



Figure 3. SWMM 5.0.016 Cross section geometry for the two rectangular links.

Suggestion for Entering Population DWF Data at a Node

I (and a few others) think a welcome change to the DWF dialog in SWMM 5 would be the addition of another scale factor to modify the average flow field. The purpose of the scale factor would be to allow the users to enter the DWF contributing population * the various DWF patterns * the scale factor (in units of cfs/person or l/s/person) in the Inflows dialog. Some users of SWMM 5 prefer to use population directly in the GUI rather than doing this calculation externally and entering either the flow in cfs or l/s. An example of why this would be useful is a future conditions model in which the population either increases or decreases in the catchment.

New Warning Messages in SWMM 5.0.014 to 5.0.016

These warning and error messages were added in SWMM 5.0.0.14 to 5.0.016 to trap questionable raingage, link and node data. Correcting these errors does make a better model . The list shown below has the major new warnings and errors and help on interpreting the messages.

WARNING 01: wet weather time step reduced to recording interval for Rain Gage

Explanation: The user selected hydrology time step is automatically reduced by the engine to match the rain gage interval. The smallest rainfall interval among all of the gages will be used during the simulation.

WARNING 02: maximum depth increased for Node

Explanation: The rim elevation of a node has to be at least equal to the crown elevation of the highest connecting link to the node. The maximum depth of the node is increased to match the highest crown elevation.

WARNING 03: negative offset ignored for Link

Explanation: Negative Offsets are set to offsets of 0.0

WARNING 04: minimum elevation drop used for Conduit

Explanation: If the elevation across the link length is less than 0.001 feet then the elevation drop is set to 0.001 feet (internal units).

WARNING 05: minimum slope used for Conduit

Explanation: If the link slope is less than the user defined minimum slope then the engine will set the slope of the link to the minimum slope.

WARNING 06: dry weather time step increased to the wet weather time step

Explanation: The Dry hydrology time step cannot be less than the wet weather hydrology time step.

WARNING 07: routing time step reduced to the wet weather time step

Explanation: Routing step set to the wet hydrology time step.

ERROR 112: elevation drop exceeds length for Conduit

Explanation: The drop across the conduit cannot exceed the conduit length. It indicates short conduits that likely have improper offset elevations or incorrectly estimated lengths based on the large offsets of the conduit.

ERROR 134: Node has illegal DUMMY link connections.

Explanation: This means either the model has more than one Ideal Pump connecting the same upstream and downstream nodes or a dummy link with more than one link exiting its upstream node.

ERROR 151: a Unit Hydrograph in set has invalid time base.

Explanation: The value of T*K or the Time Base for a RDII Unit Hydrograph has a value less than the rain gage interval. The fundamental time unit for Unit Hydrographs is the rain gage time interval.

ERROR 157: inconsistent rainfall format for Rain Gage

Explanation: Two or more gages using the same time series have different rainfall types in the rain gage definition. For example, intensity and volume.

ERROR 159: inconsistent time interval for Rain Gage

Explanation: The rain gage user defined rainfall interval does not match the actual rainfall time series.

ERROR 173: Time Series has its data out of sequence

Explanation: A time series has either the same time value for consecutive intervals or the time values are out of numerical order.

Peeling Back Pavement to Expose Watery Havens

Source: http://www.nytimes.com/2009/07/17/world/asia/17daylight.html?_r=1&partner=rss&emc=rss

Image via Wikipedia

Peeling Back Pavement to Expose Watery Havens
By ANDREW C. REVKIN
SEOUL, South Korea — For half a century, a dark tunnel of crumbling concrete encased more than three miles of a placid stream bisecting this bustling city.

The waterway had been a centerpiece of Seoul since a king of the Choson Dynasty selected the new capital 600 years ago, enticed by the graceful meandering of the stream and its 23 tributaries. But in the industrial era after the Korean War, the stream, by then a rank open sewer, was entombed by pavement and forgotten beneath a lacework of elevated expressways as the city’s population swelled toward 10 million.

Today, after a $384 million recovery project, the stream, called Cheonggyecheon, is liberated from its dank sheath and burbles between reedy banks. Picnickers cool their bare feet in its filtered water, and carp swim in its tranquil pools.

The restoration of the Cheonggyecheon is part of an expanding environmental effort in cities around the world to “daylight” rivers and streams by peeling back pavement that was built to bolster commerce and serve automobile traffic decades ago.

In New York State, a long-stalled revival effort for Yonkers’s ailing downtown core that could break ground this fall includes a plan to re-expose 1,900 feet of the Saw Mill River, which currently runs through a giant flume that was laid beneath city streets in the 1920s.

Cities from Singapore to San Antonio have been resuscitating rivers and turning storm drains into streams. In Los Angeles, residents’ groups and some elected officials are looking anew at buried or concrete-lined creeks as assets instead of inconveniences, inspired partly by Seoul’s example.

By building green corridors around the exposed waters, cities hope to attract affluent and educated workers and residents who appreciate the feel of a natural environment in an urban setting.

Environmentalists point out other benefits. Open watercourses handle flooding rains better than buried sewers do, a big consideration as global warming leads to heavier downpours. The streams also tend to cool areas overheated by sun-baked asphalt and to nourish greenery that lures wildlife as well as pedestrians.

Some political opponents have derided Seoul’s remade stream as a costly folly, given that nearly all of the water flowing between its banks on a typical day is pumped there artificially from the Han River through seven miles of pipe.

But four years after the stream was uncovered, city officials say, the environmental benefits can now be quantified. Data show that the ecosystem along the Cheonggyecheon (pronounced chung-gye-chun) has been greatly enriched, with the number of fish species increasing to 25 from 4. Bird species have multiplied to 36 from 6, and insect species to 192 from 15.

The recovery project, which removed three miles of elevated highway as well, also substantially cut air pollution from cars along the corridor and reduced air temperatures. Small-particle air pollution along the corridor dropped to 48 micrograms per cubic meter from 74, and summer temperatures are now often five degrees cooler than those of nearby areas, according to data cited by city officials.

And even with the loss of some vehicle lanes, traffic speeds have picked up because of related transportation changes like expanded bus service, restrictions on cars and higher parking fees.

“We’ve basically gone from a car-oriented city to a human-oriented city,” said Lee In-keun, Seoul’s assistant mayor for infrastructure, who has been invited to places as distant as Los Angeles to describe the project to other urban planners.

Some 90,000 pedestrians visit the stream banks on an average day.

What is more, a new analysis by researchers at the University of California, Berkeley, found that replacing a highway in Seoul with a walkable greenway caused nearby homes to sell at a premium after years of going for bargain prices by comparison with outlying properties.

Efforts to recover urban waterways are nonetheless fraught with challenges, like convincing local business owners wedded to existing streetscapes that economic benefits can come from a green makeover.

Yet today the visitors to the Cheonggyecheon’s banks include merchants from some of the thousands of nearby shops who were among the project’s biggest opponents early on.

On a recent evening, picnickers along the waterway included Yeon Yeong-san, 63, who runs a sporting apparel shop with his wife, Lee Geum-hwa, 56, in the adjacent Pyeonghwa Market.

Mr. Yeon said his family moved to downtown Seoul in the late 1940s, and he has been running the business for four decades. He said parking was now harder for his customers. But “because of less traffic, we have better air and nature,” he said.

He and his wife walk along the stream every day, he added. “We did not think about exercising here when the stream was buried underground,” Mr. Yeon said.

The project has yielded political dividends for Lee Myung-bak, a former leader of construction companies at the giant Hyundai Corporation. He was elected Seoul’s mayor in 2002 largely around his push to remove old roads — some of which he had helped build — and to revive the stream. Today he is South Korea’s president.

Even strong critics of the president tend to laud his approach to the Cheonggyecheon revival, which involved hundreds of meetings with businesses and residents over two years.

A recent newspaper column that criticized the president over a police raid on squatters ended with the words “Please come back, Cheonggyecheon Lee Myung-bak!” — a reference to the nickname he earned during the campaign to revive the stream.

The role of Seoul’s environmental renewal in Mr. Lee’s political ascent is not lost on Mayor Philip A. Amicone of Yonkers, a city of 200,000 where entrenched poverty had slowed a revival project. Once the river restoration was added to the plan, he said, he found new support for redevelopment.

Yonkers has gained $34 million from New York State and enthusiastic support from environmental groups for the river restoration, which is part of a proposed $1.5 billion development that includes a minor-league ballpark. The river portion is expected to cost $42 million over all.

A longtime supporter was George E. Pataki, who helped line up state money in his last year as governor, Mayor Amicone said. “Every time he’d visit, he’d say, ‘You’ve got to open up that river,’ ” he added.

Part of the plan would expose an arc of the river and line it with paths and restaurant patios that would wrap around a shopping complex and the ballpark. Another open stretch would become a “wetland park” on what is now a parking lot.

Mr. Amicone, who has a background as a civil engineer, said the example of Seoul’s success had helped build support in Yonkers. In an interview, he recalled the enthusiasm with which Mr. Lee, then Seoul’s mayor, toured Yonkers in 2006 and discussed the cities’ parallel river projects with him.

“Whether it’s a city of millions or 200,000, the concept is identical,” Mr. Amicone said. “These are no longer sewers, but aesthetically pleasing assets that enhance development.”

Jean Chung contributed reporting.

Surcharge Level in SWMM 5

How does the surcharge depth work in SWMM 5?



The surcharge depth from the node attribute table is added to the maximum full depth in the routine dynwave.c as an upper bound check for the new iteration depth of yNew.



    // --- determine max. non-flooded depth

    yMax = Node[i].fullDepth;

    if ( canPond == FALSE ) yMax += Node[i].surDepth;







If the new depth yNew is greater then yMax then the program will calculate either the amount of flooding from the node or the ponded depth and volume.  If the node cannot pond (canPond is False) then the amount of overflow is the excess flow in the node and the new depth yNew is set to yMax.







    if ( canPond == FALSE )

    {

        Node[i].overflow = (Node[i].oldVolume + dV - Node[i].fullVolume) / dt;

        Node[i].newVolume = Node[i].fullVolume;

        yNew = yMax;

    }

    else

    {

        Node[i].newVolume = Node[i].fullVolume + (yNew-yMax)*Node[i].pondedArea;

        Node[i].overflow = (Node[i].newVolume - Node[i].fullVolume) / dt;

    }

        if ( Node[i].overflow < FUDGE ) Node[i].overflow = 0.0;

    return yNew;



As an example, if the node floods then the depth will go above the manhole rim elevation as the following image shows.



If the ponded area of the node is zero then any excess flow is lost as overflow and the depth only stays at the rim elevation.

Q full vs Q dynamic vs Q normal

1. It gets more flow than qFull because the water in the pipe has more than just the bed slope to push it - it also has the water surface slope.
There is about a 5 meter head pushing the water out if you the bed slope to the water surface slope - see the HGL Plot.

2. The Q dynamic or St. Venant flow uses ALL of the information you have about the condition in the link (see the next image) so the flow is greater than Qfull and Q normal flow. The information includes the hydraulic radius and cross sectional areas for upstream, midpoint and the downstream ends of the links.

Future Rainfall

Published: April 2009

Outlook: Extreme

As the planet warms, look for more floods where it’s already wet and deeper drought where water is scarce.

By Elizabth Kolbert

The world's first empire, known as Akkad, was founded some 4,300 years ago, between the Tigris and the Euphrates Rivers. The empire was ruled from a city—also known as Akkad—that is believed to have lain just south of modern-day Baghdad, and its influence extended north into what is now Syria, west into Anatolia, and east into Iran. The Akkadians were well organized and well armed and, as a result, also wealthy: Texts from the time testify to the riches, from rare woods to precious metals, that poured into the capital from faraway lands.

Then, about a century after it was founded, the Akkad empire suddenly collapsed. During one three-year period four men in succession briefly claimed to be emperor. "Who was king? Who was not king?" a register known as the Sumerian King List asks.

For many years, scholars blamed the empire's fall on politics. But about a decade ago, climate scientists examining records from lake bottoms and the ocean floor discovered that right around the time that the empire disintegrated, rainfall in the region dropped dramatically. It is now believed that Akkad's collapse was caused by a devastating drought. Other civilizations whose demise has recently been linked to shifts in rainfall include the Old Kingdom of Egypt, which fell right around the same time as Akkad; the Tiwanacu civilization, which thrived near Lake Titicaca, in the Andes, for more than a millennium before its fields were abandoned around A.D. 1100; and the Classic Maya civilization, which collapsed at the height of its development, around A.D. 800.

The rainfall changes that devastated these early civilizations long predate industrialization; they were triggered by naturally occurring climate shifts whose causes remain uncertain. By contrast, climate change brought about by increasing greenhouse gas concentrations is our own doing. It, too, will influence precipitation patterns, in ways that, though not always easy to predict, could prove equally damaging.

Warm air holds more water vapor—itself a greenhouse gas—so a hotter world is a world where the atmosphere contains more moisture. (For every degree Celsius that air temperatures increase, a given amount of air near the surface holds roughly 7 percent more water vapor.) This will not necessarily translate into more rain—in fact, most scientists believe that total precipitation will increase only modestly—but it is likely to translate into changes in where the rain falls. It will amplify the basic dynamics that govern rainfall: In certain parts of the world, moist air tends to rise, and in others, the moisture tends to drop out as rain and snow.

"The basic argument would be that the transfers of water are going to get bigger," explains Isaac Held, a scientist at the National Oceanic and Atmospheric Administration's Geophysical Fluid Dynamics Laboratory at Princeton University. Climate models generally agree that over the coming century, the polar and subpolar regions will receive more precipitation, and the subtropics—the area between the tropical and temperate zones—will receive less. On a regional scale, the models disagree about some trends. But there is a consensus that the Mediterranean Basin will become more arid. So, too, will Mexico, the southwestern United States, South Africa, and southern Australia. Canada and northern Europe, for their part, will grow damper.

A good general rule of thumb, Held says, is that "wet areas are going to get wetter, and dry areas drier." Since higher temperatures lead to increased evaporation, even areas that continue to receive the same amount of overall precipitation will become more prone to drought. This poses a particular risk for regions that already subsist on minimal rainfall or that depend on rain-fed agriculture.

"If you look at Africa, only about 6 percent of its cropland is irrigated," notes Sandra Postel, an expert on freshwater resources and director of the Global Water Policy Project. "So it's a very vulnerable region."

Meanwhile, when rain does come, it will likely arrive in more intense bursts, increasing the risk of flooding—even in areas that are drying out. A recent report by the United Nations' Intergovernmental Panel on Climate Change (IPCC) notes that "heavy precipitation events are projected to become more frequent" and that an increase in such events is probably already contributing to disaster. In the single dec­ade between 1996 and 2005 there were twice as many inland flood catastrophes as in the three decades between 1950 and 1980.

"It happens not just spatially, but also in time," says Brian Soden, a professor of marine and atmospheric science at the University of Miami. "And so the dry periods become drier, and the wet periods become wetter."

Quantifying the effects of global warming on rainfall patterns is challenging. Rain is what scientists call a "noisy" phenomenon, meaning that there is a great deal of natural variability from year to year. Experts say that it may not be until the middle of this century that some long-term changes in precipitation emerge from the background clatter of year-to-year fluctuations. But others are already discernible. Between 1925 and 1999, the area between 40 and 70 degrees north latitude grew rainier, while the area between zero and 30 degrees north grew drier. In keeping with this broad trend, northern Europe seems to be growing wetter, while the southern part of the continent grows more arid. The Spanish Environment Ministry has estimated that, owing to the combined effects of climate change and poor land-use practices, fully a third of the country is at risk of desertification. Meanwhile, the island of Cyprus has become so parched that in the summer of 2008, with its reservoir levels at just 7 percent, it was forced to start shipping in water from Greece.

"I worry," says Cyprus's environment commissioner, Charalambos Theopemptou. "The IPCC is talking about a 20 or 30 percent reduction of rainfall in this area, which means that the problem is here to stay. And this combined with higher temperatures—I think it is going to make life very hard in the whole of the Mediterranean."

Other problems could follow from changes not so much in the amount of precipitation as in the type. It is estimated that more than a billion people—about a sixth of the world's population—live in regions whose water supply depends, at least in part, on runoff from glaciers or seasonal snowmelt. As the world warms, more precipitation will fall as rain and less as snow, so this storage system may break down. The Peruvian city of Cusco, for instance, relies in part on runoff from the glaciers of the Quelccaya ice cap to provide water in summer. In recent years, as the glaciers have receded owing to rising temperatures, Cusco has periodically had to resort to water rationing.

Several recent reports, including a National Intelligence Assessment prepared for American policymakers in 2008, predict that over the next few decades, climate change will emerge as a significant source of political instability. (It was no coincidence, perhaps, that the drought-parched Akkad empire was governed in the end by a flurry of teetering monarchies.) Water shortages in particular are likely to create or exacerbate international tensions. "In some areas of the Middle East, tensions over water already exist," notes a study prepared by a panel of retired U.S. military officials. Rising temperatures may already be swelling the ranks of international refugees—"Climate change is today one of the main drivers of forced displacement," the United Nations High Commissioner for Refugees, António Guterres, has said—and contributing to armed clashes. Some experts see a connection between the fighting in Darfur, which has claimed an estimated 300,000 lives, and changes in rainfall in the region, bringing nomadic herders into conflict with farmers.

Will the rainfall changes of the future affect societies as severely as some of the changes of the past? The American Southwest, to look at one example, has historically been prone to droughts severe enough to wipe out—or at least disperse—local populations. (It is believed that one such megadrought at the end of the 13th century contributed to the demise of the Anasazi civilization, centered in what currently is the Four Corners.) Nowadays, of course, water-management techniques are a good deal more sophisticated than they once were, and the Southwest is supported by what Richard Seager, an expert on the climatic history of the region, calls "plumbing on a continental scale." Just how vulnerable is it to the aridity likely to result from global warming?

"We do not know, because we have not been at this point before," Seager observes. "But as man changes the climate, we may be about to find out." 

© 2009 National Geographic Society. All rights reserved.

Additional SWMM 3,4 Converter Information

Step 1: Open up or run the converter

Step 2: Define your text editor if you want to use the Edit Button

Step 3: Define the programs ini file if you want to use it multiple times

Step 4: Click on Select to convert either a Runoff, Runoff and Transport or Runoff and Extran

Step 5: Click on Convert to convert the two selected files

Step 6: File Converted Message will tell you that the file9s) were converted correctly.

Step 7: Please make sure to check the log file to confirm that everything was converted successfully.

SWMM5 Advanced Calibration File Formats

SWMM 5 Calibration Files

Steps for making calibration files from the SWMM 5.



Step 1.  Run the model and graph at least one Object class such as Nodes, Links or Subcatchments







Step 2:  Use the Command Copy To to bring up the Saving Selection Dialog







Step 3.  Select the type of Calibration File you want based on the Selection List







Step 4:  Go to the Calibration Data Selection Menu







Step 5:  Select the correct type of Calibration Data









Step 6:  Click on the Edit Button and paste the data you saved to the clipboard into the Text Box







Step 7: Graph with the Calibration Data





Step 8: Graph with the Calibration Data in Date/Time Format







Step 9: Graph with the Calibration Data in Date/Time Format







 

International Conference on Stormwater and Urban Water Systems Modeling

International Conference on Stormwater Urban Water Systems Modeling

Thursday and Friday February 19-20, 2009

http://www.computationalhydraulics.com/Training/Conferences/program.html

SWMM 5 Variable Time Step

Topic:  The Variable time step and the Adjustment Factor.  The adjustment factor lowers the internal time step used in the model.  In the example model the lowering of the Adjustment factor from 75 percent to 25 percent lowers the minimum simulation time step from 20 second to 3 seconds.  The inflow and outflow of the model stays the same, what changes is the computed internal time step based on the Courant CFL condition.



At each time step the minimum CFL time step is calculated based on the length of the link (delta x), the ending velocity at the last time step in the link (V) and the ending link depth at the last time step (D).

SWMM 5 Complexity Index

SWMM 5 Complexity Index

The complexity index for SWMM 5 compares a model to the first Extran example in Extran 3, which would be network #1 in this expanded SWMM 5 network. The baseline network has 22 objects and an 8 hour simulation duration. It took 5 minutes to run this network on a IBM AT in 1988.  The purpose of the complexity index is to supply a means of comparison for a present day model.   The complexity equation compares the number of objects in the new model to the number of objects in the baseline model and also factors in any increase in simulation duration.







The complexity index adds up the of raingages, subcatchments, junctions, outfalls, dividers, storages, conduits, pumps, orifices, weirs, outlets, control curves, diversion curves, pump curves, rating curves, shape curves, storage curves, tidal curves, time series, patterns, transects, hydrographs, aquifers, controls, climate objects and snowpacks objects. The complexity index is then multiplied by the number of pollutants for all subcatchments, junctions, outfalls, dividers, storages, conduits, pumps, orifices, weirs and outlets and it also includes the number of landuses times the number of subcatchment objects.



The complexity index is compared to the network #1 by dividing the calculated complexity index by the base line 22 objects and dividing the duration of the new network by the 8 hour duration of the baseline network. The network shown above has a complexity index of 5.2 and runs in less than 1 second on a Intel Dual Core Processor.

The complexity index was 88.5 for sake of comparison for the model USER4.INP in the zip file DATA.ZIP in epaswmm5_qa.zip on the EPA SWMM 5 QA/QC suite of files.   The complexity index was 7.4 for the model USER1.INP in the zip file DATA.ZIP.  The complexity index was 55 for the model USER2.INP in the zip file DATA.ZIP. The complexity index was20.1 for the model USER3.INP in the zip file DATA.ZIP.  The complexity index was 18.5 for the model USER5.INP in the zip file DATA.ZIP.

SWMM 5 Pond Infiltration

You can model the pond infiltration indirectly by using either:

1. a Pump Type 4 (the classic SWMM 4 solution to this matter), in which the Pump simulates the pond depth - infiltration rate function,

2. alter the SWMM 5 Evap Factor for a pond so that you have seasonal or monthly variation in your infiltration loss simulated as an increase in Pan Evaporation or

3. You can use the newer SWMM 5 Outlet structure and use either a functional or tabular relationship to simulate the infiltration loss as a function of pond depth.

If you search the CHI Knowledge database you can also find some suggestions from Mike Gregory (and others) about modeling infiltration loss from a pond. I would recommend items 2 and 3 because "An outlet curve in SWMM 5 has the same functionality as a SWMM 4 Depth related pump ( Flow versus Depth) but it has the great advantage of being explicitly designed to have multiple functions; does not have the appearance of being an ad hoc solution (as a pump simulating infiltration would be to the casual viewer) and has many wonderful other features (added by Lewis Rossman) that you would not get with a strict pump link."

SWMM 5 Variable Time Step

SWMM 5 Variable Time Step

In the SWMM 5 Simulation Options/Dynamic Wave Options is the Variable Time Step Frame which contains the Adjustment Factor Percentage. The Adjustment Factor is a multiplication factor on the CFL condition.

The effiect of changing the Adjustment factor can be seen in the following graph. As the value of the adjustment factor changes from 75 to 50 to 25 the time step used in the program decreases because the time step gets further away from the CFL time step condition.

SWMM5 Normal Flow

Option "Define Supercritical Flow By" does inside the SWMM 5 engine. The options are called Slope, Froude and Bothin the GUI and in the engine of SWMM 5. A few other variable definitions you need to know to understand this explanation are: (1) Y1 for the upstream link depth, (2) Y2 for the downstream link depth, (3) Q for the flow in the link, (4)Qfull for the full Manning's equation flow or normal flow for the link based on the bed slope, (5) Froude1 and Froude2 for the Froude Number respectively of the upstream and downstream ends of the link, (6) n for Manning's roughness, (7) Yfull for the maximum depth of the link and (8) Qnormal for the Normal Flow equation flow based on the upstream area of the link (A1) and the upstream hydraulic radius (R1).



In the SWMM 5 engine these options are used after the dynamic wave equation flow is estimated using the St. Venant equation. The option that you choose is only active for those links that have a flow greater than 0, links with negative flow use the dynamic wave equation flow exclusively. It the flow is positive and the link is an open channel and full then the minimum of the dynamic wave flow or Qfull is used as the new flow in the link. If the flow is positive and the depth at the upstream end of the link or Y1 is less than Yfull then the engine will compare Qnormal to Q using the routines in Check Normal Flow.



If the link gets to the Check Normal Flow routines then it uses the following logic:

• If the Slope or Both option is used or either the upstream node or the downstream node of the link is an outfall AND Y1 is less than Y2 then the minimum of Q from the dynamic wave equation or Q from the Normal Flow equation is used as the current iteration flow in link, or


• If the Froude or Both option AND either the upstream Froude Number or the downstream Froude number is greater than 1 then the minimum of Q from the dynamic wave equation or Q from the Normal Flow equation is used as the current iteration flow in link. This condition is never used if either of the connecting nodes of the link are outfalls.

How does this work in the actual flow that SWMM 5 estimates for a link? Consider this example in which the link flow in blue is plotted with the Qnormal flow in red and the Q dynamic wave equation flow in purple:



Qnormal is







Qnormal is only calculated when the link is not full so in the plot a Qnormal of 0 means that the pipe was full. At other times the flow in the link was equal to Qnormal as the minimum of the dynamic equation flow or the Qnormal flow is used at each iteration in the solution process. The flow is normally bounded by the Qnormal flow in SWMM 5.0.013. Your choice of the options Slope, Froude andBoth really only impact the conditions under which this comparison is true. If you use Froude or Both then Supercritical flow at either end of the link will trigger this comparison will be the dynamic wave equation flow and the Froude number at each end of the link.

Smaller Storms Drop Larger Overall Rainfall In Hurricane Season

Smaller Storms Drop Larger Overall Rainfall In Hurricane Season

ScienceDaily (Dec. 11, 2007) — Researchers have found that when residents of the U.S. southeastern states look skyward for rain to alleviate a long-term drought, they should be hoping for a tropical storm over a hurricane for more reasons than one. According to a new study using NASA satellite data, smaller tropical storms do more to alleviate droughts than hurricanes do over the course of a season by bringing greater cumulative rainfall.

A new study that provides insight into what kind of storms are best at tackling drought in the southeastern United States. The study focuses on a decade of first-ever daily rainfall measurements by a NASA satellite carrying a weather radar in space. The study's authors believe the same insights can be applied by meteorologists and public officials to other regions where daily satellite rainfall data and storm tracking data are available.

In the wake of Hurricane Katrina, meteorologist Marshall Shepherd, an associate professor of geography and atmospheric sciences at the University of Georgia, Athens, and colleagues delved into the ongoing debate about whether global warming is leading to an increase in rainfall intensity. The researchers wanted to determine how much rainfall each type of cyclone, from tropical depressions to category five hurricanes, contributes to overall rainfall. They focused the study on the Southeast in the hope that results could be harnessed to improve drought relief information for the region. Their findings were published today in the American Geophysical Union's Geophysical Research Letters.

"As much of the Southeast experiences record drought, our findings indicate that weak tropical systems could significantly contribute to rainfall totals that can bring relief to the region," said Shepherd, lead author of the NASA-funded study. "These types of storms are significant rain producers. The larger hurricanes aren't frequent enough to produce most of the actual rain during the season and therefore are not the primary storm type that relieves drought in the region."

Shepherd created a new measurement method as an efficient way to get a real sense for how much rainfall each type of storm contributes in a given year around the coastal regions of the southeastern U.S. To do so, he had to distinguish an average rainfall day from an extreme rainfall day. Though data from NASA's Tropical Rainfall Measuring Mission (TRMM) satellite could offer daily rainfall amounts, the data could not be used to set apart whether rainfall was average or extreme for any given day.

Shepherd and his team modeled their metric on the "cooling degree day" that energy companies use to relate daily temperature to energy needs for air conditioning. A cooling degree day is found by subtracting 65 degrees from the average daily temperature. Values larger than zero give some indication whether a day was abnormally warm. Shepherd used daily rainfall data from TRMM to determine 28.9 as the base value of average daily rainfall at one of the world's wettest locations, Maui's Mount Wailea in Hawaii.

In the same way as the cooling degree day, the "millimeter day" metric is calculated by subtracting 28.9 millimeters from the average daily rainfall in each of four ocean basins along coastal areas scattered across the south near Houston and New Orleans, east of Miami and south of North Carolina. Values greater than zero indicate a so-called "wet millimeter day" of extreme rainfall.

Using daily rainfall data from the TRMM satellite from 1998-2006, Shepherd's team compared the amount of rain that fell in the basins on extreme rainfall days with the location of tropical storms from the National Hurricane Center's storm tracking database to determine how many extreme rainfall days were associated with a particular type of tropical storm.

The team found that the most extreme rainfall days occurred in September and October, two of the busiest months of the Atlantic hurricane season. They also found that though major hurricanes produced the heaviest rainfall on any given day, the smaller tropical storms and depressions collectively produced the most rainfall over the entire season. Over half of the rainfall during the hurricane season attributed to cyclones of any type came from weaker tropical depressions and storms, compared to 27 percent from category 3-5 hurricanes.

TRMM has transformed the way researchers like Shepherd measure rainfall by providing day-to-day information that did not exist before the satellite's 1997 launch. "Though we've had monthly rainfall data available since 1979 from other sources, it's the daily rainfall data that allows us to see that tropical storm days contributed most significantly to cumulative rainfall for the season due to how frequently that kind of storm occurs," said Shepherd.

"It's important in the future to build a longer record of daily rainfall to establish, with better confidence, whether trends are occurring," said Shepherd. "This study sets the stage for us to understand how much rainfall weak and strong tropical cyclones contribute annually and whether this contribution is trending upward in response to global warming-fueled growth in tropical cyclones."

Shepherd believes advances that will improve study of cyclones and rainfall are "just around the corner" with NASA's Global Precipitation Measurement satellite, scheduled for launch in 2013. An extension of TRMM's capabilities, it will measure precipitation at higher latitudes, the actual size of snow and rain particles, and distinguish between rain and snow.
Adapted from materials provided by NASA/Goddard Space Flight Center, via EurekAlert!, a service of AAAS.
Email or share this story:
Need to cite this story in your essay, paper, or report? Use one of the following formats:
APA

MLA
NASA/Goddard Space Flight Center (2007, December 11). Smaller Storms Drop Larger Overall Rainfall In Hurricane Season. ScienceDaily. Retrieved November 27, 2008, from http://www.sciencedaily.com­ /releases/2007/12/071210104022.htm

How to Make an InfoSWMM model from the DBF Files

Follow the following steps to create MY .MXD file.

1) Open an empty InfoSWMM project. Do not initialize it.

2) Save the project as MY .MXD within the folder where you have MY. ISDB

3) Initialize the project.

4) Click the reset Display button

That should create the project for you.  If you want an H2OMAP SWMM project, you can save the InfoSWMM model, and then Import it from H2OMAP SWMM.

Annotated SWMM 5.0.013 Output File

See Note on SWMM 2009

Force Main Transition in SWMM 5

Force Main Transition between Partial and Full Flow

1. If the force main is full then the program will use either Hazen-Willams or Darcy-Weisbach to calculate the friction loss (term dq1),

2. If the force main is NOT full then the program will use Manning's Equation.


// --- compute terms of momentum eqn.:
// --- 1. friction slope term
if ( xsect->type == FORCE_MAIN && isFull )
dq1 = dt * forcemain_getFricSlope(j, fabs(v), rMid);
else dq1 = dt * Conduit[k].roughFactor / pow(rWtd, 1.33333) * fabs(v);

double forcemain_getFricSlope(int j, double v, double hrad)
//
// Input: j = link index
// v = flow velocity (ft/sec)
// hrad = hydraulic radius (ft)
// Output: returns a force main pipe's friction slope
// Purpose: computes the headloss per unit length used in dynamic wave
// flow routing for a pressurized force main using either the
// Hazen-Williams or Darcy-Weisbach flow equations.
// Note: the pipe's roughness factor was saved in xsect.sBot in
// conduit_validate() in LINK.C.
//
{
double re, f;
TXsect xsect = Link[j].xsect;
switch ( ForceMainEqn )
{
case H_W:
return xsect.sBot * pow(v, 0.852) / pow(hrad, 1.1667); //(5.0.012 - LR)
case D_W:
re = forcemain_getReynolds(v, hrad);
f = forcemain_getFricFactor(xsect.rBot, hrad, re);
return f * xsect.sBot * v / hrad;
}
return 0.0;
}

World Rainfall

SCS Rainfall Distributions and Design Storms

SCS Rainfall Distributions for H20MAP and InfoSWMM

The base file has a 24 hyetograph for SCS Type 1A and SCS Type 2 distrubutions. The total of the rainfall is 1 inch and to make a 25 year or 50 year storm you follow these steps:

1. Clone the rainfall time series and

2. Use the Field Calculator in DB Edit to change the total rainfall by using the operand in the Field Calculator dialog. For example, the picture shown below will make a 10 inch 24 hour rainfall in the new time series.

You will end up with two series: (1) the base 1 inch hyetograph and (2) the new design storm of 10 inches.

H2OMAP and InfoSWMM Sediment Transport Modeling

H2OMAP SWMM and InfoSWMM Sediment Transport Modeling

Sanitary and combined sewer systems can carry substantial loads of suspended solids (waste solids) which can accumulate and cause blockages thereby impairing the hydraulic capacity of the sewer pipes (by restricting their flow area and increasing the bed friction resistance). H2OMAP SWMM and InfoSWMM can simulate the transport and gravitational settling of (total suspended solids including grit) over time throughout the sewer collection system under varying hydraulic conditions. As long as flow velocity exceeds the critical/terminal velocity, H2OMAP SWMM and InfoSWMM assumes that the sewage flow has the capacity to transport all incoming . Deposited  particles are also assumed to be scoured and transported downstream when velocity of the sewage flow exceeds the terminal velocity. Settling starts when flow velocity falls below the critical velocity. In the model, transport of thet particles is governed by advection implying that the particles are transported at local flow velocity. 

The sediment transport modeling using H2OMAP SWMM and InfoSWMM  requires only few inputs, namely limiting flow velocity, particle settling velocity, and source node(s) and initial concentrations (in mg/l) at the source nodes. 

In order to specify the first two inputs (i.e., limiting flow velocity and particle settling velocity), the user should first select from the quality tab which in turn activates the editing tabs for particle settling velocity and limiting flow velocity. Specification of source node(s) and its/their initial concentration is similar to the method described above in relation to pollutant transport. The default values used by the model for limiting flow velocity and particle settling velocity are 2 ft/s and 0.1 ft/s, respectively.  User specified values over rid these default figures .

H2OMAP SWMM and InfoSWMM  deposition (in kg)  in pipes and  concentration (in mg/l) at manholes,  wet wells, and outlets are the outputs reported following successful simulation of  transport for a collection system.

Modified Basket Handle Cross Section Warnings

There is a rule in SWMM 5 that the depth cannot be less than half the bottom width for a modified basket handle(see below).  You always have to have a maximum depth less than 50 percent or 1/1 of the bottom width,  If you do not meet this criterion then the program will generate an invalid number warning.  This is the code from xsect.c that checks the validity of the cross section data:

    case MOD_BASKET:

        if ( p[1] <= 0.0 || p[0] <>

        xsect->yFull = p[0]/ucf;

        xsect->wMax  = p[1]/ucf;

Wave Of Sewage Flows Toward Tampa Bay

TBO > News

Wave Of Sewage Flows Toward Bay

Tribune photo by CANDACE C. MUNDY

Workers with Spectrum Underground Inc. work to repair a 20-inch sewage pipeline which broke in Town 'N Country this afternoon.

The Tampa Tribune

Published: September 13, 2008

TOWN 'N COUNTRY - Approximately 200,000 gallons of untreated sewage spilled into Sweetwater Creek on Friday afternoon, prompting a warning to residents along the creek to avoid the water, Hillsborough County officials said.

The spill occurred along Comanche Avenue just east of Hanley Road when a 20-inch sewage pipeline ruptured. The break was at a connection point to a section that had been replaced about eight weeks ago, officials said.

Because the work had been done so recently, it was under warranty, and the original contractor returned to fix the break, said Bill Bozeman, project manager for the county's water resource services. Bozeman did not know what caused it.

The fracture, reported by a passer-by at about 12:45 p.m., caused sewage to spill onto Hanley Road and ooze down Comanche toward the creek. The flow was contained two hours later. After five hours, a cloud of sewage still fogged the water along one of the creek's banks.

The section of Comanche where the spill occurred is home to a couple of businesses and a small strip of offices under construction. A narrow bridge over Sweetwater Creek leads to a neighborhood and to Sweetwater Organic Community Farm.

The farm does not rely on the creek for irrigation and the creek in that section is too shallow and choked with overgrowth in places for kayaking or swimming. County workers posted signs in English and Spanish notifying visitors of high bacterial levels and a health risk, telling them not to swim, wade or fish in the water.

Residents along the creek, which flows south to the Courtney Campbell Parkway area, are urged not to have any contact with the water for the next several days in the creek or the area where it flows into Tampa Bay.

While the contractor worked to repair the pipe, the county diverted the flow from nearby lift stations that serve the areas into tanker trucks.

The spill did not affect home use of water, Bozeman said.

The Water Resource Services staff will notify local and state environmental agencies, take samples and monitor the area where the spill occurred.

Google Knol's about SWMM

SWMM3,4 Conversion to SWMM 5

This site contains links and a description of Tools for converting Visual SWMM, XP-SWMM, SWMM 3, 3.5 and 4.x data sets...

Published version 4. Last Edited on Tue Aug 05 20:56:37 PDT 2008

SWMM 5 or 5.0 Links

Stormwater Management Model (SWMM) Information for watershed water quality, hydrology and hydraulics modelers (not associa...

Published version 2. Last Edited on Sat Aug 30 19:57:42 PDT 2008

SWMM Link Upstream Weighting

Purpose: The purpose of this note is to explain a significant dynamic wave routing difference between EPA SWMM 5.0.013...

SWMM 5 Spatial Step

SWMM 3,4,5 uses a spatial step equal to the length of the link.

SWMM 5 Links

More Information about the Stormwater Management Model (SWMM) for watershed water quality, hydrology and hydraulics...

Published version 4. Last Edited on Wed Aug 13 11:26:34 PDT 2008

Google Site for SWMM5

Manual de SWMM 5 en espanol

Manual de SWMM 5 en espanol
http://www.gmmf.upv.es/descargas/manualSWMM.pdf

SWMM 5 View Variables

SWMM 5 View Variables

There are four types of graphical variables in SWMM 5: (1) Subcatchements, (2) System, (3) Nodes and (4) Links.  The SWMM 5 Hydrology binary graphics file consists of 21 view variables for each subcatcment simulation in SWMM 5.  The variables are:

    

Subcatchment Variables	Description
SUBCATCH_RAINFALL	rainfall intensity
SUBCATCH_SNOWFALL	snowfall intensity
SUBCATCH_RUNOFF	total runoff flow rate
SUBCATCH_RUNOFF_IMPZero	runoff flow rate from zero imp area feb 2007
SUBCATCH_RUNOFF_IMP	runoff flow rate from imp area feb 2007
SUBCATCH_RUNOFF_Pervious	runoff flow rate from pervious area feb 2007
SUBCATCH_LOSSES	total losses (infil)
SUBCATCH_EVAP	watershed evaporation loss
SUBCATCH_DEPTH	watershed depth
SUBCATCH_GW_FLOW	groundwater flow rate to node
SUBCATCH_GW_FLOW_A1	groundwater flow rate to node
SUBCATCH_GW_FLOW_A2	groundwater flow rate to node
SUBCATCH_GW_FLOW_A3	groundwater flow rate to node
SUBCATCH_GW_ELEV	elevation of saturated gw table
SUBCATCH_GW_THETA	soil moisture
SUBCATCH_GW_PERCOLATION	aquifer deep percolation
SUBCATCH_SNOWMELT	watershed snow melt
SUBCATCH_SNOWDEPTH	watershed snow depth
SUBCATCH_FREEWATER	watershed snow depth
SUBCATCH_COLD	watershed cold content
SUBCATCH_SNOWAREA	watershed snow coverage
SUBCATCH_UL	soil thickness
SUBCATCH_FTOT	infiltration during an event
SUBCATCH_FU	current value of F
SUBCATCH_FUMAX	maximum value of F
SUBCATCH_MOISTURE	current soil mositure (less than porosity)
SUBCATCH_IMD	current IMD (Porisity - Moisture)
SUBCATCH_IMDbyEvent	IMD at the beginning of an event
SUBCATCH_SAT	Flag for saturation (1 is saturated)
SUBCATCH_INFIL_TIME	GA infiltration time
SUBCATCH_WLMAX	current infiltration RATE
SUBCATCH_NETPRECIP	rainfall intensity
SUBCATCH_BUILDUP	pollutant buildup concentration
SUBCATCH_WASHOFF	pollutant washoff concentration

The SWMM 5 system binary graphics file consists of 25 variables on one line for each system variable simulated in SWMM 5.  The variables are: 

System Variables	Description
SYS_TEMPERATURE	air temperature
SYS_WINDSPEED	wind speed
SYS_RAINFALL	rainfall intensity
SYS_SNOWFALL	snow depth
SYS_RUNOFF	runoff flow
SYS_LOSSES	evap + infil
SYS_EVAP	evap
SYS_DWFLOW	dry weather inflow
SYS_GWFLOW	ground water inflow
SYS_IIFLOW	RDII inflow
SYS_EXFLOW	external inflow
SYS_INFLOW	total lateral inflow
SYS_FLOODING	flooding outflow
SYS_OUTFLOW	outfall outflow
SYS_STORAGE	storage volume
SYS_CE	continuity error for the basin
SYS_ITERATIONS	average iterations over the basin
SYS_SNOWDEPTH	snow depth
SYS_COLD	cold storage for the basin
SYS_SNOWMELT	snowmelt for the basin
SYS_RAINMELT	rainmelt for the basin
SYS_TS	time steps during the simulation
SYS_DWFLoad	total K3 line DWF load
SYS_WWFLoad	total K3 line WWF load
SYS_WWFLoadExtra	agency extra WWF Load

The SWMM 5 Node graphics binary file consists of 20 variables on one line for each junction/storage/outfall/divider  simulated in SWMM 5.  The variables are: 

Node Variables	Description
NODE_DEPTH	water depth above invert
NODE_HEAD	hydraulic head
NODE_VOLUME	volume stored & ponded
NODE_LATFLOW	lateral inflow rate
NODE_IIFLOW	total rdii inflow rate
NODE_UH1	total rdii inflow rate from UH 1
NODE_UH2	total rdii inflow rate from UH 2
NODE_UH3	total rdii inflow rate from UH 3
NODE_DWFFLOW	total DWF inflow rate
NODE_INFLOW	total inflow rate
NODE_OUTFLOW	total outflow rate
NODE_OVERFLOW	overflow rate
NODE_CE	node ce
NODE_AREA	node surface area
NODE_DQDH	node surcharge dqdh
NODE_DENOM	node surcharge dqdh
NODE_ITERATIONS	node iterations to this time step
NODE_TIMESTEP	node iterations to this time step
NODE_CONVERGENCE	node iterations to this time step
NODE_QUAL	concentration of each pollutant

Link Variables

How Much Can You Learn From a Home DNA Test?

How much does your DNA determine your future? Our reporter has her DNA analyzed by three different labs, and shares every detail of the results... as well as how she copes with them.

read more | digg story

EMC Washoff in SWMM5

There are four steps to using EMC concentrations in your network:

1. Define your pollutant by adding a pollutant using the Data=>Quality=>Pollutant command:

2. Define the Land Use by using the Data=>Land Uses command or the Land Use Editor:

3. Define Buildup to be None by clicking on the None Tab:

4. Define the EMC Washoff concentration by clicking on the Washoff Tab:

More: http://www.swmm2000.com/

Inlets

 

 

 

 

Hurricane Dennis, Tampa 2005

 

 

 

 

Papaya Bugs and Gators

Papaya Bugs and Gators in the Backyard

A bug on our backyard Papaya trees. The papaya trees survived but the frost of January 2008 killed many of the trees. They are growing back, however.

PuddleBlog

PuddleBlog is the image history of one small to large puddle on an American Street:

What is Puddleblog, you ask? Puddleblog chronicles the epic journey of one puddle, bracing for an uncertain future.

It’s a blog. You know, for a puddle. Specifically, the puddle that graces the corner of Jay and Plymouth, a couple blocks east of the Manhattan Bridge. Maybe if this thing catches on we can think about including other qualified puddles.

www.epaswmm.info

Note www.epaswmm.info now forwards to www.swmm2000.com which forwards to swmm2000.ning.com one of the wonderful Ning social network sites.

www.swmm5.info

Note www.swmm5.info now forwards to www.swmm2000.com which forwards to swmm2000.ning.com one of the wonderful Ning social network sites.

www.swmm.info

Note www.swmm.info now forwards to www.swmm2000.com which forwards to swmm2000.ning.com one of the wonderful Ning social network sites.

SWMM 3,4 to 5 Converter Interface

SWMM 3,4 to 5 Converter Interface
The SWMM 3 and SWMM 4 converter can convert up to two files at one time to SWMM 5. Typically you would convert a Runoff and Transport file to SWMM 5 or a Runoff and Extran File to SWMM 5. If you have a combination of a SWMM 4 Runoff, Transport and Extran network then you will have to convert it in pieces and copy and past the two data sets together to make one SWMM 5 data set.

The x,y coordinate file is only necessary if you do not have existing x, y coordinates on the D1 line of the SWMM 4 Extran input data set.



You can use the command File=>Define Ini File to define the location of the ini file. The ini file will save your conversion project input data files and directories.



You can use the command File=>Define Your Text Editor to define the location of the text editor program. The ini file will save your conversion project editor name.



You can get a copy of the latest SWMM 3,4 to 5 Converter Here..

Google Site for SWMM5

Google Sites is a recent addition to the Google family that allows you to set up a collaborative web site focused on one or more topics. In the words of Google:

"Meet Google Sites, the newest addition to the Google Apps product suite. It was designed to allow you to easily create a network of sites and share them with whomever you choose. Google Sites lets you pull together information from across Google Apps by embedding documents, spreadsheets, presentations, videos, and calendars in your sites. Of course, we also harness the power of Google search technology so your search results are always fast and relevant."

The Google Site SWMM2000+ has so far duplicate information copied from the SWMM Ning Sites and the SWMM5 Blogspot.

Gators and Stormwater Outfalls

A four foot gator living in a Stormwater Outfall in Florida.

---

swmm5/red

Hydrology in Ecclesiastes

Hydrology in Ecclesiastes

1:5 The sun also ariseth, and the sun goeth down, and hasteth to his place where he arose.

1:6 The wind goeth toward the south, and turneth about unto the north;
it whirleth about continually, and the wind returneth again according
to his circuits.

1:7 All the rivers run into the sea; yet the sea is not full; unto the
place from whence the rivers come, thither they return again.

Note: This was a better description than in Aristotle.

Hurricne Ivan in Pittsburgh, 2004

Pittsburgh International Airport recorded the highest 24-hour rainfall for Pittsburgh, recording 5.95 in. of rain. NWS Pittsburgh Climate Data, August, 2004." Hourly Climate Data. Pittsburgh, PA. 21 June 2006. http://www.erh.noaa.gov/pbz/hourlyclimate.htm

SWMM Notes Home

If you are new to this site or revisiting please visit Notes Home to see a roadmap to the Notes. SWMM 5 Input Files and Notes can be found in SWMM5. SWMM 4 Input Files and Notes can be found in SWMM4.

Spatial Step

SWMM 3,4,5 uses a spatial step equal to the length of the link. Or, in terms of the 1D St. Venant Equation for the calculation of flow used in SWMM 5:







In which is the length of the conduit.



The program will calculate the cross sectional area, hydraulic radius top width and depth at the upstream, midpoint and downstream sections of the link. The link solution is pivoted on the midpoint cross sectional area in the dominant dynamic wave terms and

and the non-linear term in the dynamic wave equation uses the upstream and downstream link cross sectional areas. In the finite difference equation in SWMM 5 the pipe shown below would have one length but use the cross sectional information from the upstream, midpoint and downstream points of the link.



The bend in the pipe would be modeled using the "other" category of losses

SWMM 5 Tools

In the newest version of EPA SWMM (5.0.1.11), there is a new feature of allowing for Add-ins and third-party tools. One such Add-in, the Microsoft Excel, can be very helpful for input data editing and model calibration.

1. To activate the Add-in
This process is detailed in pp. 141 of the EPA SWMM manual (http://www.epa.gov/ednnrmrl/models/swmm ... manual.pdf). Basically the user needs to go to "Tools->Program Preferences->Configure Tools" on SWMM main menu. Then in the pop-up "Tool Options" menu choose "Add." A "Tool Properties" window will pop-up, and the user can assign a name to the Excel Add-in for the "Name" field. For the "Program" field, the user needs to navigate to the location of the Excel executable file at "C:\Program Files\Microsoft Office\Office10\Excel.exe" (the file path may vary). Leave the "Working Directory" field as blank, and choose "INPFILE" macro for the "Parameters" field. Check both "Disable SWMM while executing" and "Update SWMM after closing."

After the above is set up, click OK and the Excel Add-in is registered in SWMM5. The Add-in tool is under the "Tools" menu. One important thing now is to go to "Tools->Program Preferences," and in the pop-up window check "Tab Delimited Project File."

2. Use the Excel Add-in
The SWMM5 input file by default is a tab-delimited .txt file. The user can view the file using Wordpad, but the editing is not very convenient, especially when it comes to calibration for a watershed with large number of subbasins. The Excel Add-in provides great relief for such operations.

Create a simple watershed model in SWMM, and then go to "Tools->Excel Editor (or whatever the user names the Add-in)." The input file for the watershed model is then displayed in tab-delimited format in Excel. In this environment, the user can edit the input data much easier (as compared to double-click each model component and key in the values in the Graphic User Interface). This becomes more apparent when the number of subbasins increases. When the editing is finished, close the Excel program, and then click "YES" or "OK" to all the pop-up windows. After that, the SWMM model interface pops back and the input parameters are updated.

So with this knowledge the model setup process can be much easier. In the initial model setup, the user may not bother to input any parameter values (i.e. subbasin area, width, slope, etc.). Instead, the model can be delineated and all components represented. Then the user can open the "Excel Editor" and copy/paste the model parameter values from another table of pre-created input parameter values (which is always the case). This process will totally by-pass the manually key-in of parameter values.

The second case of this feature applies is the model calibration. In a traditional way, suppose the user needs to change the value of depression storage for the impervious area. That means for a 30-subbasin watershed, the user needs to roam around the watershed and double-click 30 times to finish that single parameter change. Imagine if it takes five times to find the best value for that single parameter. With this feature, the user can open up the input file, set a depression storage value for the first subbasin, and then drag down for all the other 29 subbasins. Close Excel and go back to SWMM, and the updated model can be ran immediately.

Source: http://ceeforums.com/forum/viewtopic.php?f=26&t=256&p=582#p582

Global Rainfall

QA/QC Version of SWMM 5

This is my explanation of the comments on on the blog http://hhwq.blogspot.com about the CDM version of SWMM 5. It was purely a QA/QC testing program used in the code and data set migration of SWMM 4 to SWMM 5 during the years 2004 to 2007.

CDM version of SWMM5

CDM makes available their version version of SWMM5 for download and use. There's a few more options and the GUI element edit boxes have a lot more variable options. Otherwise, it looks, feels, and acts like the EPA version (from what I've have discerned).

http://groups.google.com/group/swmm5

4 comments:

Robert said...

This version is a QA/QC version of SWMM 5 that was used to more closely compare the SWMM 4 to SWMM 5 results using extra data variables.

April 19, 2008 8:35 PM

Robert said...

It should not be used for modeling. You should use the EPA SWMM Web site to download the latest EPA SWMM version:

http://www.epa.gov/ednnrmrl/models/swmm/index.htm

April 19, 2008 8:36 PM

EPA SWMM 5 Calibration Files

The EPA SWMM 5 calibration file is only for comparing the following 12 internal variables graphically to either SWMM 4 results, monitored data or some other model results:

1. 

1. Subcatchment Runoff
2. Subcatchment Washoff
3. Node Water Depth
4. Link Flow Rate
5. Node Water Quality
6. Node Lateral Inflow
7. Node Flooding
8. Groundwater Flow
9. Groundwater Elevation
10. Snow Pack Depth
11. Link Flow Depth
12. Link Flow Velocity

The graph on your SWMM 5 screen can be saved either to the clipboard or an external file for further manipulation of the computed and observed (calibration file data) by using the commands

Edit->Copy To=>Clipboard=>Text or

Edit->Copy To=>File=>Text

Just remember that the computed variable value comes first in the text followed by the observed variable value. For example:

Link 1030 Flow
Series Elapsed Time (hours) Flow CFS
Computed 0.1667 0.0000
.
.
Observed 0.0167 0.0000

The Joys Of Non-Driving

Andrew Sullivan - SWMM 2008 - Stormwater Management Model

The Joys Of Non-Driving

22 Jun 2008 09:33 pm

It proves I'm not an American, I guess, but I still don't know how to drive, don't have a license and have managed to get to the age of 44 without missing one. Yes, the husband has to drive us all the way to Ptown each summer, but once I get here, even more than when I'm in DC, this sentiment by C.S. Lewis rings all the more true:

I number it among my blessings that my father had no car, while yet most of my friends had, and sometimes took me for a drive. This meant that all these distant objects could be visited just enough to clothe them with memories and not impossible desires, while yet they remained ordinarily as inaccessible as the Moon. The deadly power of rushing about wherever I pleased had not been given me. I measured distance by the standard of man, man walking on his two feet, not by the standard of the internal combustion engine. I had not been allowed to deflower the very idea of distance; in return I possessed "infinite riches" in what would have been to motorists "a little room."

The truest and most horrible claim made for modern transport is that it "annihilates space." It does. It annihilates one of the most glorious gifts we have been given. It is a vile inflation which lowers the value of distance, so that a modern boy travels a hundred miles with less sense of liberation and pilgrimage and adventure than his grandfather got from traveling ten. Of course if a man hates space and wants it to be annihilated, that is another matter. Why not creep into his coffin at once? There is little enough space there.

$4 gas? Maybe it will be good for us.

Permalink :: Trackback (0) :: Sphere It!

Data Set Backwards Compatibility

The SWMM 5 data input files are not backwards compatible with previous versions of SWMM - you cannot open a file created in v13 with a v11 GUI without getting messages about Options or features present in v13 but not present in v11. Not everyone looks at the C code but the new options are listed in the file enums.h with a version notation:

SKIP_STEADY_STATE, TEMPDIR, IGNORE_RAINFALL, //(5.0.010 - LR)
FORCE_MAIN_EQN, LINK_OFFSETS, //(5.0.012 - LR)

The good feature about this message is that it tells you what MAY be different between the two SWMM versions. For example, if you used Link Offsets in v13 then you will not have a valid model in SWMM 5.0.011. However, if you are not using a new option in SWMM 5.0.013 then you will have a valid backwards compatible SWMM 5.0.011 input data set.

SWMM 5 GUI Compile Options

These are the Delphi 7 options that should be used to prevent the integer overflow problem from occurring when using the Zoom command. Overflow checking and any Debugging options seem to be the cause of the integer overflow problem.

A charming little rain garden shines on Mt. Washington

Source: http://www.popcitymedia.com/timnews/raingarden0521.aspx

May 21, 2008

A charming little rain garden shines on Mt. Washington

A lovely little rain garden has showered a once blighted corner on Mt. Washington, a splash of green that its creators’ hope may become a catalyst for sprinkling similar projects around Pittsburgh.

Pittsburgh’s Burt Hill dreamed up the idea pro bono as a way to expand the firm’s professional knowledge and investigate emerging environmental technologies for urban water runoff, explains Evaine Sing, graduate landscape architect. The project has become a labor of love on a 2,000 square foot parklet on the corner of Shiloh Street and Virginia Avenue.

Mt. Washington Community Development Corp., URA Mainstreets Pittsburgh Fund and Pittsburgh Public Works have assisted along the way and $10,000, labor and material donations were contributed by community members and local businesses including Shemin Nurseries and KMA/Landscape Forms.

“We wanted a project of our own that would work as a test kitchen for other projects and be a living example for our clients,” explains Sing. “We choose this site across from the CDC because we saw the potential for educating passersby on these sustainable methods.”

The park was subdivided into small ecosystems and plants were selected for their ability to absorb water and pollutants during rainstorms. Bioretention beds and vegetated swales will allow the garden to drain within 2 days, helping to absorb and prevent storm water runoff, explains Sing.

Other touches will include lighting, a plaza space, benches, stepping stones made from the recycled pavers, an electrical outlet for future concerts and a mural that will be created by Cory Bonnet.

“We’d love to see this kind of space happen more often in Pittsburgh, like 10,000 Rain Gardens in Kansas City, which has had an amazing impact on water quality and flooding,” adds Sing. “We hope the idea will spread.”

Writer: Debra Smit
Source: Evaine Sing, Burt Hill; Greg Panza, MWCDC

Image courtesy Burt Hill

SWMM History

SSO Fawn Ridge

Sanitary Sewer Overflow in the Street Draining to a Detention Pond

SWMM Link Upstream Weighting

Purpose: The purpose of this note is to explain a significant dynamic wave routing difference between EPA SWMM 5.0.013 and EPA SWMM 5.0.011 and before. A few people have detected a difference. The previous solution(s) would use only the midpoint area (Amid) and hydraulic radius (Rmid) in the dynamic wave solution. The new solution will use a slider or linear combination of the midpoint area (Amid) and hydraulic radius (Rmid) and the upstream cross sectional area (A1) and hydraulic radius (R1). The slider is based on the Froude number in the link. The change involves the A and R link spacing in the two dominant terms of the St. Venant Equation:


The new method is a linear combination or slider that weights the value of A and R in the St. Venant Equation based on the value of rho (), or



where, Rho () is a function of the Froude number. The effect of this addition is that as the Froude number increases from 0.5 to 1.0 and beyond the area and hydraulic radius used as the pivot point in the St. Venant equation moves from the midpoint of the link to the upstream end of the link. When the Froude number is above 1.0 the St. Venant and Normal Flow equation both use the same cross sectional area and hydraulic radius which makes for a more stable model.

Just for reference, the equation for Qnorm or the Manning's Equation flow is



The equations for the calculation of Rho () as a function of the Froude Number (Fr) are:



If ALL of the follow conditions are true Rho ()is calculated:

• the pipe is not full,
• h1 >= h2, and
• qLast > 0.

where,
h1 is the head at the upstream end of the link,
h2 is the head at the downstream end of the link and
qLast is the last flow value in the link.

If any of these conditions are true then rho = 1.0 and the value of A and R are the values Amid and Rmid, respectively.
The next graph shows the relationship between Rho and the Froude Number.



The value of Awtd and Rwtd move from the midpoint of the link to the upstream end of the link as the Froude number increases from 0.5 to 1.0.




Conclusion: This change should make the solution more stable because there is no longer an oscillation between the St. Venant Equation A and R and the Normal Flow Equation A and R.

Batch Files

How to Use the SWMM 4 Dos Enginengine

• SWMM Engine Name Name of the SWMM 4 DOS Engine
• SWMM Input File - SWMM 4 Input file
  
• SWMM Output File - SWMM 4 Text Output File (.OUT Extension)
• Alternative SWMM Output File - Reduced SWMM 4 Output File (.RPT Extension)

How to Use the SWMM 5 Dos Engineine

• SWMM Engine Name Name of the SWMM 5 DOS Engine (usually called SWMM5.EXE)
  
• SWMM Input File - SWMM 5 Input file
  
• SWMM Output File - SWMM 5 Output Binary Graphics File (.OUT Extension)
  
• Alternative SWMM Output File - SWMM 5 Output Text File (.RPT Extension)

SWMM 5 Notes

Click on the URL Link to get the RTF SWMM 5 Notes.
SWMM 5 Notes

SWMM5 Calibration Files

Calibration File Description

SWMM 5 Google Page Links, Links and More Links

SWMM5.COM - More SWMM5 Links, Links and More Links

SWMM 5 Water Quality Files

The 15 water quality examples are at this site: SWMM 2000

Why the Concept of Billable Time is Bad for Creativity

I have worked at companies that had billable goals and at companies that did not have billable goals. I find that I work much longer hours when I do not have a billable goal. It may be a psychological ploy but if you have to work by the hour on various projects and you are in a position in which you do not get paid overtime then any hours that you are not billable seem wasted hours. Conversely, if I am paid a flat rate of 40 hours per week then every hour of the day seems as valuable as the next hour of the day and I find myself working again 12 to 16 hour days because I want to get the project done and move onto the next project.

SWMM 3, 4 References

Huber, W. C., J. P. Heaney, S. J. Nix, R. E. Dickinson, and D. J. Polmann, 1984. Storm Water Management Model. User's Manual Ver. III, U.S. Environmental Protection Agency.

Huber, W. C. and R. E. Dickinson, 1988, Storm Water Management Model. User's Manual Ver. IV, U.S. Environmental Protection Agency.

SWMM 3/4 to SWMM 5 Converter

We are updating the SWMM 3/4 to SWMM 5 Converter for EPA SWMM 5.0.012

Update History of SWMM 5

SWMM 5.0 Update History
=======================
--------Build 5.0.010 (6/19/07)-----------------------
Engine Updates:
1. All "float" variables were re-declared as "doubles" (except for those variables written to binary interface files) and the engine was re-compiled using the Microsoft VC++ 2005 compiler.
2. A new NO ROUTING option was added which allows a run to ignore any flow routing and only compute runoff (see swmm5.c, keywords.c, stats.c, and enums.h).
3. A new type of pump, an Ideal Pump, was added which pumps at a rate equal to the inflow to its inlet node and does not use a pump curve (see enums.h, link.c, and flowrout.c).
4. A new type of conduit shape, a Custom Shape, was added which allows users to define their own cross-sectional geometry for closed conduits. To implement this feature, a new type of curve, a Shape Curve, was added which records how the width of the cross-section varies with height. (See keywords.c, link.c, project.c, report.c, shape.c, xsect.c, enums.h, funcs.h, globals.h, objects.h, and text.h).
5. Another new type of conduit shape, a Circular Force Main, was added. It is a circular pipe that uses either the Hazen-Williams or Darcy-Weisbach equations, instead of the Manning equation, for pressurized flow only. The Hazen-Williams C-factor or the Darcy-Weisbach roughness height is one of the shape's parameters. The choice of which equation to use (for Force Mains only) is a new global option. (See project.c, forcmain.c, dynwave.c, keywords.c, link.c, xsect.c, enums.h, globals.h and text.h).
6. Pumps can now have startup and shutoff inlet node depths supplied directly as part of a pump's properties rather than as part of a control rule. (See link.c, routing.c, objects.h, and funcs.h).
7. Orifices can now have timed gate openings and closings as in SWMM 4 (i.e., the SWMM 4 ORATE parameter). (See link.c and objects.h).
8. Unit Hydrographs used for RDII inflows can now have an initial abstraction loss associated with them. Consult the Users Manual or the Help file for details. (See rdii.c and objects.h).
9. A new criterion was added to determine when a conduit has supercritical flow and therefore normal flow conditions might apply. It is based on both water surface slope and the Froude number (as opposed to just one or the other). (See dynwave.c, project.c, keywords.c, enums.h, and text.h).
10. A Flow Instability Index is now computed for each non-pump link. It counts the number of time steps in which the link's flow is either higher or lower than the flows at the previous and next time steps. The Status Report lists the links with the five highest indexes. (See objects.h, stats.c, and report.c).
11. Node volumes are now initialized to take account of any initial ponding that may be implied by the node depth stored in a hot start file (see flowrout.c).
12. The area corrections to the inlet and outlet loss terms under dynamic wave flow routing that were introduced in Build 5.0.008 were removed (see dynwave.c).
13. To comply more closely with standard hydraulic practice, the head across an orifice is now computed with respect to the midpoint of its opening, rather than to the bottom. Also, orifices are now treated the same as weirs in terms of not contributing any surface area to their end nodes (see link.c and dynwave.c).
14. The partly opened setting for an orifice is now interpreted as fraction of the full orifice opening height available rather than as the fraction of the full area available. Also, the equivalent discharge coefficient for a partly full orifice is now re-computed whenever the setting of the orifice changes (see link.c).
15. In kinematic wave flow routing, when a conduit's inflow is limited to its maximum normal flow, its corresponding inflow area is now correctly normalized to the full flow area (see kinwave.c).
16. For dynamic wave flow routing, the criteria used to check if a node is not full before using its depth to compute a variable time step was corrected to avoid excessively small time steps (see dynwave.c).
17. The width v. depth table for circular shapes was expanded to 51 entries to match that of the other tables for this shape (see xsect.dat).
18. The number of entries in the geometry tables for irregular cross-sections was increased to 51 entries (see objects.h).
19. For Divider nodes, both end nodes of the diversion link are now checked to see if one of them is connected to the divider node (see node.c).
20. Conditions on Outlet links are now correctly recognized in control rule statements and an error message is now generated if more than one rule clause is placed on the same line (see controls.c).
21. When the Ignore Rainfall option is used, a rain gage's rainfall is now properly initialized to 0 to prevent a spurious rainfall value from being reported (see gage.c).
22. An explicit check is now made in the engine (which already exists in the GUI) to see if the ID name of the outlet of a subcatchment exists as both a node and a subcatchment. If so, then Error 108 is thrown. (See subcatch.c).
23. The column in the Node Depth Summary of the Status Report that previously displayed the total volume of ponded water at each node (but was labelled "Total Flooding") now displays the maximum volume of ponded water at each node and is labelled "Max Vol. Ponded". Also, flow values appearing in the Status Report's tables were expanded to 3 decimal places for MGD and CMS units, and an additional decimal place was added to ponded area and conduit length in the report's Input Summary tables (see stats.c and report.c).
24. When a node is ponded under dynamic wave routing, the water depth is now always set equal to the ponded depth rather than the smaller of the ponded and dynamic depths (see dynwave.c).
25. A more efficient way of processing the mathematical expressions used in treatment functions has been implemented (see mathexpr.h, mathexpr.c, and objects.h).
26. A bug in the Groundwater routine that allowed infiltration to continue even when the entire groundwater table was saturated was fixed as was a metric units conversion error on computed groundwater flow (see gwater.c).
27. The locations of the left and right overbank stations for an irregular channel transect are now adjusted by the Station Modifier multiplier, in the same way as all of the other station locations across the transect are.
28. An error in computing the flow contribution of the triangular ends of a trapezoidal weir was corrected (see link.c).
29. A roundoff error under kinematic wave and steady flow routing that sometimes caused nodes to be incorrectly reported as ponded was fixed (see flowrout.c).
GUI Updates:
1. A "Tools" item was added to SWMM's main menu. The existing menu options to set Program Preferences and Map Display Options were moved there. In addition, it contains a "Configure Tools" option that can be used register add-in tools with SWMM 5. Consult the Users Manual or the Help file for more information regarding add- in tools. 2. A "None" option was added to the choice of routing methods on the General page of the Simulation Options dialog to accommodate the new No Routing analysis option.
3. The Property Editor for Pumps was modified to allow the Pump Curve field to remain blank (or accept a *) to signify the new Ideal type pump and to accept startup and shutoff depths.
4. The Property Editor for orifices was modified to include a Time To Close/Open field.
5. The Unit Hydrograph Editor dialog was modified to include the new Initial Abstraction parameters.
6. The Analysis Options dialog was modified to accommodate the new supercritical flow criterion.
7. The Cross-Section Editor and the Curve Editor were modified to accommodate the new Custom cross-section shape feature as well as the new Circular Force Main shape.
8. The File Export menu has a new option that, once a run has been successfully made, will export the node and link results at the current time period being viewed to a Hotstart file.
9. The popup menu for toggling the map's Auto-Length feature was replaced with a check box on the Status Panel.
10. A check box was added to the Map Dimensions dialog to ask if conduit lengths and subcatchment areas should be recomputed when the Auto- Length setting is on.
11. The Group Delete feature now offers the option of only deleting objects with a specific value for their Tag property.
12. Ponded Area was added to the list of node parameters that can be assigned a default value through the Project >> Defaults menu item.
13. The epaswmm5.ini file that contains a user's program preferences is now saved to the users Application Data folder, in a sub-folder named EPASWMM, rather than to the user's home folder.
14. Conduit slopes are no longer displayed as absolute values, so that negative slopes will show up on a thematic display on the study area map and will also be identified when a map query is made.
15. The bitmap image on the Run speed button was replaced.
16. The automatic identification of a connected path of links between two nodes specified on the Profile Plot dialog now uses the path with the smallest number of links.
17. The Study Area Map's Zoom Out feature no longer uses a zoom out to previous extent. Instead it zooms out relative to the current center of the map.
18. The Animator toolbar was made a permanent part of the Map Browser panel.
19. The operation of the date and time controls on the Map Browser panel were modified to work correctly with reporting times that are larger than 1 day.
-----------------------Build 5.0.009 (9/19/06)-----------------------Engine Updates:1. A climate file in the user-prepared format will no longer be confused with one using the Canadian format (see climate.c).2. The minimum runoff which can generate pollutant washoff was changed from 0.001 in/hr to 0.001 cfs (see subcatch.c).3. A new RDII event now begins when the duration of a continuous run of dry weather exceeds the base time of the longest unit hydrograph rather than arbitrarily being set at 12 hours (see rdii.c).4. Problems with dynamic flow routing through long force mains connected to Type 3 and Type 4 pumps have been corrected (see dynwave.c and link.c).
GUI Updates:1. A problem in displaying profile plots when all elevations are below zero has been corrected.
----------------------Build 5.0.008 (7/5/06)----------------------Engine Updates:1. The conversion from the Horton infiltration drying time input parameter to an equivalent regeneration curve constant was corrected.2. Pipe invert elevations at outfalls are now measured relative to the outfall stage elevation rather than the outfall's invert elevation.3. Entrance/exit minor loss terms for dynamic wave flow routing are now adjusted by the ratio of the mid-point to entrance/exit areas to improve the energy balance.4. A possible error in computing flow depth from head when checking the normal flow limitation based on the Froude number for dynamic wave flow routing was corrected.5. A potential problem with converting the units of rainfall read from an external file was corrected.6. The equivalent length of orifices and weirs was changed from being a minimum of 200 ft to a maximum of 200 ft.7. Problems in displaying washoff mass balance results for pollutants expressed as Counts/Liter were fixed.8. The reporting of total system maximum runoff rate in the Status Report's Subcatchment Runoff Summary table has been corrected.9. The subcatchment pollutant washoff process was reprogrammed to provide more rigorous mass balance results for the case where runoff from one subcatchment is routed over another subcatchment or when there is direct deposition from rainfall.10. Checks for non-negative conduit offsets and orifice/ weir/outlet heights have been added.11. A constant value and a scaling factor have been added to Direct External inflows. See the Inflows Editor - Direct Page topic in the Help file for more details.12. A listing of total washoff loads for each pollutant for each subcatchment has been added to the Status Report.13. A new summary table of Node Inflows and Flooding has been added to the Status Report.14. A new summary table of Outfall flows and pollutant loads has been added to the Status Report.15. The 5.0.006 Engine Update #12 has been revoked.
GUI Updates:1. The Inflows Editor was modified to accommodate the baseline and scaling parameters added to direct external inflows.2. The .INI file that saves a user's program preferences is now saved to the user's home directory rather than the SWMM installation directory.3. The Select All command was extended to apply to the Status Report display.4. A new text file viewer component was used for the Status Report to speed up the display of the report's contents.5. A formating error on the Horizontal Axis page of the Graph Options dialog form was corrected. This required making changes to the custom Chart Dialog component that is included with the GUI's source code.6. Some cosmetic changes were made to the look of Tabular reports.7. Type 3 pump curves (head v. flow) are now displayed with head on the vertical axis and flow on the horizontal axis when the View option is selected in the Curve Editor dialog.
-----------------------Build 5.0.007 (3/10/06)-----------------------Engine Updates:1. An "Ignore Rainfall" analysis option was added that causes the program to only consider user-supplied external inflow time series and dry weather flows and ignore any rainfall inputs that would otherwise produce runoff.2. The hydraulic radius calculations for Rectangular-Closed, Rectangular-Triangular, and Rectangular-Round conduit shapes were modified to account for the increase in wetted perimeter that occurs under full flow due to the top surface.3. Refinements were made in several places in the code that need to distinguish between Full Flow and Maximum Flow conditions in closed conduits.4. The code now properly accounts for the case where the depth at which the maximum normal flow occurs through an irregular shaped cross section is less than the full depth.5. The final volume of any ponded water (caused by node flooding) is now included in the reported flow continuity error.6. Peak runoff flow was added to the Subcatchment Summary table in the Status Report.7. Non-conduit links are now included in the Link Flow Summary table of the Status Report.
GUI Updates:1. The Maximum Depth field in the Property Editor for a conduit with an irregular shape now shows the correct value for any set of transect elevation values.2. The "Save Profile to File" button is now enabled when the user manually adds a specified set of links to the Profile Plot dialog.3. Link Flow Depth and Link Velocity have been added as choices for calibration variables.4. The way that non-conduit links are displayed on profile plots was changed to avoid problems that occurred for weirs and orifices with crest heights above the node invert.5. A problem with the way that the Group Editing function was handling the case of irregular shaped cross sections was fixed.
-------------------------Build 5.0.006a (10/19/05)-------------------------Engine Updates:1. The formula for snow melt rate during periods with rainfall was corrected to return its value in ft/sec rather than in/hr.2. A problem with generating routing interface files for systems with just nodes and no links was corrected.
GUI Updates:1. Numerical precision problems in computing centroids for subcatchments with very small distances between vertices were fixed.2. A problem with no calibration data being shown on a time series graph when some of the data were outside the range of the graph was fixed.3. A problem with calibration data represented as dates (not elapsed time) being shifted one reporting period over in time series graphs that used elapsed time was fixed.
----------------------Build 5.0.006 (9/5/05)----------------------Engine Updates:1. A new summary table of maximum volumes and outflow rates for each storage unit has been added to the Status Report.2. The SWMM 4 BC parameter, which specifies a minimum groundwater table elevation for groundwater flow to occur, was added as an optional groundwater flow parameter. If not provided then as before, the invert of the receiving node defines the minimum groundwater table elevation for flow to begin.3. A new option was added to the Action clause of a control rule that allows the control setting for pumps, orifices, weirs, and outlets to be defined either by a curve (of setting versus node depth, for example) or by a time series. See the "Modulated Controls" topic in the Help file for more details.4. The problem with interior nodes being mistaken for outfall nodes (depending on the orientation of the connecting links) under water quality analyses was fixed.5. Geometry tables for standard size elliptical pipes were added (the standard size code number in the input file was being mistaken for an actual dimension).6. Storage curves of area versus depth are now linearly extrapolated when a depth exceeds the table limit (as in SWMM 4) rather than just keeping the area constant.7. Evaporation is no longer computed from a storage unit when it becomes dry.8. In water quality routing, concentrations in storage units are now adjusted to reflect any evaporation loss over each time step.9. It is now permissible to use the same hotstart file to both provide initial values for a run and to save the final values from a run.10. The code was modified to be able to read evaporation values from a climate file during runs where no runoff computations are being made (previously any evaporation in such files was being ignored in data sets with no subcatchments).11. A problem in the way that water quality was being routed through dummy conduits was fixed.12. For pollutant treatment functions that define fractional removal in a storage unit node as a function of concentration, the concentration used is now the inflow concentration into the node (as is done for non-storage nodes), rather than the concentration in the storage unit.13. The global first-order decay reaction assigned to specific pollutants is not applied to any storage unit that has a treatment function defined for the pollutant.14. The total moisture available for infiltration at each time step of the runoff process now has evaporation subtracted from it before infiltration is computed.15. Corrections were made to the way that the water volume in the upper soil zone is depeleted during dry periods under Green- Ampt infiltration.16. A climate file is now positioned to begin reading at the start of the simulation period (rather than the start of the file) unless the user supplies a specific starting date to begin reading from the file.17. A fatal error is now generated if the end of a climate file is reached when seeking climate data during a run (rather than just maintaining the same climate values for the remainder of the run).18. The Node and Conduit flow statistics that appear in the Status Report are now only collected over the reporting period of the simulation, not the entire period (as would be the case when the user specifies a Report Start Date that comes after the Simulation Start Date).19. The computation of the initial and final groundwater storage volumes used in the Groundwater Continuity table were corrected. This error only affected the continuity numbers and not the computed flows and water table levels.
GUI Updates:1. The File >> Reopen command will now list up to 10 most recently used files.2. Map coordinates are now displayed with 3 decimal places in the Status Bar.3. The File >> Preferences dialog now contains a "Prompt to Save Results" option. If left unchecked, simulation results will always be saved when a project file is closed and will be available for viewing the next time the project is opened.4. A "Report Elapsed Time by Default" option was also added to the File >> Preferences dialog. If checked, then time series graphs and tables will default to using elapsed time, rather than date/time, as the time variable. This choice can always be changed in the dialog box that appears when a graph or table is first created.5. Additional reporting variables were added to the list of parameters for which Calibration Files can be used (e.g., groundwater elevation, node flooding, etc.).6. Percent impervious was added to the list of subcatchment themes that can be viewed on the Study Area Map.7. An Exceedance Frequency plot panel was added to the output produced when a Statistics report is generated.8. Users can now add, delete, or re-position items in the list of links selected for a Profile Plot in the Profile Plot dialog using a new set of buttons added to the dialog. Links are added to the list by selecting the link either on the Map or from the Data Browser and then clicking the PLUS button on the dialog.9. Profile Plots can now be generated before any simulation results are available. They include an Update button that allows one to update the plot after editing changes have been made to any nodes or links contained in the plot.10. The Edit >> Find menu command (and its associated speed button) was split into two sub-commands, one for finding objects on the map (as before) and another for finding text within a Status Report.11. Problems with the wrong data fields sometimes being updated in the Group Editor were fixed.12. The Interface File Combine utility was not working at all (the format of the interface file had changed since the original code was written). This has been fixed.13. The centroids of subcatchment polygons on the map are now computed as true centroids rather than being merely the average of the vertex coordinates.14. The Maximum Depth property is now preserved when a storage unit is converted to a junction (by right-clicking on it and selecting Convert To from the popup menu).15. Map and Profile Plot animation is now turned off whenever the Animator Toolbar is closed.16. More universal support was provided for entering numerical values in scientific notation throughout the GUI's various data entry fields.17. Display problems with zoom-ins on the preview plots of Transects, Curves, and Time Series in their respective Editor dialogs were fixed.18. In the GUI source code: a. The custom TOpenTextFileDialog component was renamed to TOpenTxtFileDialog so as not to conflict with a Delphi 2005 component of the same name. b. The custom ChartDlg component was modified to add support for a chart axis that uses Date/Time labels. c. A new unit named Ucalib.pas was added that includes the code for reading data from Calibration Files that was previously contained in the Fgraph.pas unit. d. The Delphi DFM files for the project are now packaged as text files, not binaries, in the source code distribution.
------------------------Build 5.0.005b (6/15/05)------------------------Engine Updates:1. The end node offsets for conduits with the partly filled circular cross-section shape were not being increased to account for the depth of fill.2. Flow through a weir was not necessarily zero when the water level on the side of the weir at higher head was zero.3. The "crest height" for a Bottom Orifice is now interpreted as having the orifice lie in a horizontal plane the specified distance above its upstream node's invert. This allows riser outlet pipes in storage units to be simulated.
GUI Updates:1. The keyword "WEIR" was not being recognized as a legitimate type of Flow Divider node by the GUI's input data file parser.2. The Profile Plot could display hydraulic grade lines that dropped below the invert of a conduit.
------------------------Build 5.0.005a (5/25/05)------------------------Engine Updates:1. An erroneous error message that appears when a node has multiple outflow links with one of them being an Outlet link has been fixed.
GUI Updates:1. Corrections were made for the way a Profile Plot is drawn when negative elevation values occur.
------------------------Build 5.0.005 (5/20/05)------------------------Engine Updates:1. An error in computing ponded depths at flooded nodes under Dynamic Wave flow routing was corrected.2. The wrong lookup function was being used to find water elevations at Time Series type outfall nodes.3. An error in interpolating values stored on a routing interface file was corrected.4. The rainfall file reader was confusing the standard space- delimted format with other file formats.5. A reporting error for rainfall time series that had no ending zero value was corrected.6. A problem with neglecting to compute a snowmelt coefficient for pervious areas was fixed. 7. The keyword for specifying that pollutant buildup be normalized to curb length was modified to accept either CURB or CURBLENGTH.8. The conversion factor the user supplies for external pollutant mass inflows must now convert time series values into mass concentration units per second (e.g., 5.25 will convert from lbs/ day to mg/sec). Flow units are no longer part of the conversion.9. The ratio of maximum to design flow listed for each conduit in the status report was corrected to account for the number of barrels included in the conduit.10. The minimum elevation change applied to a flat conduit was changed to 0.001 feet, as used in SWMM 4.11. The maximum depth of an irregular cross-section transect is now based on the highest elevation of all stations, rather than just the higher of the first and last station, and vertical walls extending up to the higest elevation are added at the first and last station if need be.12. The nominal width property of an irregular cross-section transect is now taken as the top width at full depth rather than the maximum width over all depths.13. At outfalls where the user-specified water elevation is below that of a free outfall, the free outfall elevation is now used.14. A new property, the maximum allowable flow, was added to the Conduit object. The default value is 0.0, which indicates that no maxmimum flow is prescribed.15. Depths at outfall nodes under Steady and Kinematic Wave flow routing are now reported as the depth in the connecting conduit.16. The calculation of the head over a non-surcharged, submerged weir was corrected to be based on the height of water above the weir crest, rather than the difference in heads on either side of the weir.17. The equation used to reduce the length of a weir with side contractions was modified to fix a bug in SWMM 4.18. A new water quality routing algorithm was written that produces more robust results under Dynamic Wave flow routing.19. The Compatibility Mode option under Dynamic Wave flow routing was removed. Now there is just a single method used which has been designed to be compatible with SWMM 4 yet produce more stable results.20. A new dynamic wave routing option was added that determines which criterion decides when conduit flow is limited to normal flow (it represents the KSUPER parameter used in SWMM 4).21. A new flow routing option was added that allows routing calculations to be skipped during periods of steady flow which can greatly reduce the time required for continuous simulations.
GUI Updates:1. An error in reading the flapgate parameter for Weirs in an input file was corrected.2. Having the Property Editor positioned outside the viewable screen area when the user changed the video settings to a lower resolution was corrected.3. The Convert To option to change nodes from one type of object to another was fixed.4. The Routing Time Step option is now entered as fractional seconds on the Analysis Options form. The older format of hrs:min:sec will still be imported correctly from previous SWMM5 input files.5. The ability to include a startup input file on the command line that launches the GUI was added (add /f filename to the command line where filename is the fully qualified name of the input file to start with).6. Support for output results files greater than 2 gigabytes was added.7. The display of the hydraulic grade line in Profile Plots, and its intersection with the flow volume in conduits was improved.8. The summary results tables contained in the Status Report were modified to display more useful information.9. The graph options selection dialogs were made to behave more consistently.10. Support was added for copying and printing the graphical views of curves, time series, and transects from within their respective editors.11. The SWMM 4 flow calibration data file (Extran1.dat) distributed with the example data set Example2.inp was modified to contain the flows actually produced by SWMM version 4.4h, rather than the original numbers printed in the 1988 Extran manual.
In addition, the SWMM 5.0 Users Manual and Help file were updated toreflect these changes and new additions.
------------------------Build 5.0.004 (11/24/04)------------------------Engine Updates:1. Fixes were made to the routines that identify and read data from the NCDC-formatted external rain files.2. The sign of reported velocity in links with adverse slope was corrected.3. Reading of results from previously saved Runoff Interface files was corrected.4. The calculation of a regeneration rate constant from a soil drying time value for Curve Number infiltration was corrected, and the method was modified to use a constant infiltration capacity during each rain event, rather than a continuously declining capacity.5. A correction was made to the dynamic wave routing routine for SWMM4 and SWMM3 compatibility modes that improves the match with Extran results from these earlier versions of SWMM.6. The check for zero-sloped conduits was modified to include any conduit with elevation difference below 0.01 feet.7. The computation of the ponded depth at flooded nodes under dynamic wave flow routing was corrected.8. A check was added to make sure that the reporting time step is not longer than the run duration.9. Surcharged and high Froude number conduits were previously excluded from consideration when computing a variable time step for dynamic wave routing; they are now included.10. The code numbers for the concentration units used for each pollutant was added to the binary output file produced from a simulation.
GUI Updates:1. Negative values can now be entered for temperature values that appear on several input forms.2. The input file reader now checks to make sure that the various time- of-day option values are valid.3. A problem with copying the correct dates for a Tabular Report that is being copied to the clipboard or to a file was corrected.4. The Graph Options dialog form was modified to display the Solid option for Style whenever a Size greater than 1 is selected. (Due to a limitation of the Graphics library used in EPA SWMM, only solid lines can be drawn at a thickness greater than 1.) ------------------------Build 5.0.003 (11/10/04)------------------------Engine Updates:1. Modifications were made to full depth entries of width tables for closed rounded cross-section shapes to improve the numerical stability for dynamic wave flow routing.2. Error 405 was added to detect if the size of the binary results file would exceed the 2.1 Gbyte system limit.3. A units problem for RDII inflows under metric flow units was corrected.4. A problem reading the TEMPDIR option when it contained spaces was corrected.5. Support for Canadian DLY02 and DLY04 temperature files was added.6. Rule-based control of crest height for weirs was corrected (previously the control setting adjusted flow rather than the relative distance between weir crest and crown).
GUI Updates:1. A problem with the Group Editing feature for conduits was corrected (the editor would update the wrong conduit parameter).2. Execution time for long term simulations on smaller projects was speeded up considerably by only refreshing the progress meter every day rather than every minute.3. The time to draw time series graphs and perform statistical analyses on large data sets was considerably shortened.
-----------------------Build 5.0.002 (11/1/04)-----------------------Engine Updates1. Modifications made to the Picard method used for dynamic wave flow routing routine.
------------------------Build 5.0.001 (10/29/04)------------------------First official release of SWMM 5.

Under dynamic wave flow routing, both SWMM 4 and 5 treat conduit entrance and exit losses as an average energy loss spread over the entire length of the conduit, analagous to the way that the friction head loss is treated. However, rather than using “average” values for hydraulic variables as is done for friction loss, the entrance loss is based on values at the upstream end of the conduit while the exit loss uses values from the downstream end. It appears that hydraulic results obtained using this approach violate the Bernoulli energy equation for steady, subcritical flow conditions where conservation of energy should apply. We illustrate this point with a simple example and suggest a modification to the code that improves the energy balance obtained.

The figure below shows a simple 3 channel system with a fixed downstream boundary condition. Each channel is rectangular, with a width of 2 ft, a maximum height of 1 ft. and a roughness value of 0.01. A steady inflow of 2 cfs is introduced at the upstream end. The steady water profile that results when there are no local losses is shown in the figure.

Because the flow is steady, the Bernoulli energy equation should be satisfied across each channel link where subcritical flow conditions occur. This equation states that the total energy head at the upstream end of the channel minus any energy losses ocurring within the channel must equal the total energy head at the downstream end of the channel. For the middle channel between nodes 2 and 3 with no entrance or exit losses this equation would be:

where H_i = elevation head at node i, V_i = velocity in channel at node i, g = acceleration of gravity, and h_f = friction head loss in the channel. The latter term can be computed from the Manning equation:

where L = channel length, n = Manning roughness, V = average velocity in the channel and R = average hydraulic radius in the channel.

For the conditions shown in Figure 1, a SWMM 5 run using dynamic wave routing with inertial terms included gives the following results:

Upstream Conditions	Downstream Conditions	Average Conditions
H2 = 4.4035 ft	H3 = 2.2681 ft	Q = 2.0000 cfs
Y2 = 0.4035 ft	Y3 = 0.2681 ft	Y = 0.3358 ft
A2 = 0.8070 ft2	A3 = 0.5362 ft2	A = 0.6716 ft2
V2 = 2.4783 ft/sec	V3 = 3.7300 ft/sec	V = 2.9780 ft/sec
L = 800 ft	n = 0.01	R = 0.2514 ft
V22/2g = 0.0954 ft	V32/2g = 0.2160 ft	hf = 2.0140 ft

And the Bernoulli equation is satisfied as follows:

LHS: 4.4035 + 0.0954 – 2.0140 = 2.485

RHS: 2.2681 + 0.2160 = 2.484

Now consider what happens when an entrance loss with coefficient value of 10 is applied to the middle conduit. The Bernoulli equation is modified to include the additional loss term on the RHS:

When this entrance loss is added to the middle channel in the current version of SWMM the resulting energy balance looks as follows:

Upstream Conditions	Downstream Conditions
Helev = 4.5070 ft	Helev = 2.2681 ft
Hveloc = 0.0604 ft	Hveloc = 0.2160 ft
Hfric = 1.3212 ft	Htotal = 2.484 ft
Hent = 0.6041 ft
Htotal = 2.642 ft

These SWMM results no longer satisfy the Bernoulli equation:

If instead we introduce an exit loss with coeffcient of 10 to the middle channel the discrepancy is even worse:

Upstream Conditions	Downstream Conditions
Helev = 4.6131 ft	Helev = 2.2681 ft
Hveloc = 0.0413 ft	Hveloc = 0.2160 ft
Hfric = 0.9057 ft	Htotal = 2.484 ft
Hexit = 2.1603 ft
Htotal = 1.588 ft

We believe that the problem lies in how the entrance/exit loss value, KV_e²/2g, is embedded into the finite difference form of the momentum equation. The latter equation includes the Manning equation for the standard friction slope term:

which is a loss per unit length along the channel, with k given by g(n/1.49)². By analogy with this term, the entrance/exit loss is also expressed as an energy slope term as follows:

where the subscript e represents either the channel entrance or exit location. When the conservation of mass and momentum equations are expressed in finite difference form, the following result for flow Q at time t+t is obtained:

where has been factored out of the expressions for h_f and h_e.

Neither SWMM 4 or 5 currently contains the (A/A_e) factor when computing the entrance/exit loss term. When this term was introduced into SWMM 5, the following Bernoulli equation results were obtained for the test problem with entrance and exit losses, respectively:

Entrance Loss Example

Upstream Conditions	Downstream Conditions
Helev = 4.4859 ft	Helev = 2.2681 ft
Hveloc = 0.0658 ft	Hveloc = 0.2160 ft
Hfric = 1.4338 ft	Htotal = 2.484 ft
Hent = 0.6577 ft
Htotal = 2.460 ft

Exit Loss Example

Upstream Conditions	Downstream Conditions
Helev = 4.9136 ft	Helev = 2.2681 ft
Hveloc = 0.0186 ft	Hveloc = 0.2160 ft
Hfric = 0.3887 ft	Htotal = 2.484 ft
Hexit = 2.1603 ft
Htotal = 2.383 ft

These results are closer to meeting an energy balance but are still not perfect. One other issue to consider is how the average area A and hydraulic radius R are computed within a conduit when computing the friction head loss. This is an old topic that has seen different approaches used within various versions of SWMM. Currently, both SWMM 4 and 5 compute A and R using a depth equal to the average of the upstream and downstream depths. One alternative method is to take the average of the A and R values computed at the depths at each end of the conduit. When this method was utilized in SWMM 5 the Bernoulli results for the two test cases were as follows:

Entrance Loss Example

Upstream Conditions	Downstream Conditions
Helev = 4.4894 ft	Helev = 2.2681 ft
Hveloc = 0.0648 ft	Hveloc = 0.2160 ft
Hfric = 1.4142 ft	Htotal = 2.484 ft
Hent = 0.6483 ft
Htotal = 2.492 ft

Exit Loss Example

Upstream Conditions	Downstream Conditions
Helev = 4.9340 ft	Helev = 2.2681 ft
Hveloc = 0.0178ft	Hveloc = 0.2160 ft
Hfric = 0.3703 ft	Htotal = 2.484 ft
Hexit = 2.1603 ft
Htotal = 2.421 ft

These results come even closer to satisfying the energy balance. However, redefining the way that SWMM computes an average A and R would likely change flow and depth results for many existing models that do not include entrance/exit losses. The subsequent confusion that would occur does not seem worth the slight improvements in energy closure achieved. Therefore it is recommended that only the (A/A_e) correction be applied to the SWMM 5 code.

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