The SWMM5 engine uses mean flow as the dry weather flow value (DWF) and not population but does allow weekday, weekend, daily and monthly patterns. You can use these many pattern options to actually use population in the SWMM5 and InfoSWMM dry weather flow tables. Here are the steps as … Read the rest
Excerpt from the EPA manual Storm Water Management Model Reference Manual Volume III – Water Quality (PDF) which can be found here
Management of stormwater quality is usually performed through a combination of so-called “best management practices” (BMPs) and a form … Read the rest
Surface Ponding
Normally in flow routing, when the flow into a junction exceeds the capacity of the system to transport it further downstream, the excess volume overflows the system and is lost. An option exists to have instead the excess volume be stored atop the junction, in a ponded fashion, … Read the rest
InfoSWMM offers 12 choices for modeling surface runoff (click on link to see more information on each method):
| SWMM’s Main Window |
SWMM’s main window is pictured below. Click on a labeled element to learn more about it.
| Map Toolbar |
The Map Toolbar contains buttons for viewing the Study Area Map.
| Selects an object on the Map | |
| Selects link or subcatchment vertex points |
This file documents changes made to swmm44gu by Wayne Huber or others
since its first release on September 28, 1999.
WCH = Wayne Huber
RED = Robert Dickinson
CIM = Chuck Moore
MCH = Mitch Heineman
LR = Lew Rossman
| Unit Hydrographs |
Unit Hydrographs (UHs) estimate rainfall-dependent inflow/infiltration (RDII) into a sewer system. A UH set contains up to three such hydrographs, one for a short-term response, one for an intermediate-term response, and one for a long-term response. A UH group can have up to 12 UH … Read the rest
| Introducing EPA SWMM5 |
The EPA Storm Water Management Model (SWMM) is a dynamic rainfall-runoff simulation model used for single event or long-term (continuous) simulation of runoff quantity and quality from primarily urban areas. The runoff component of SWMM operates on a collection of subcatchment areas that receive precipitation and generate … Read the rest
| Snowmelt |
Snowmelt parameters are climatic variables that apply across the entire study area when simulating snowfall and snowmelt. They include:
| · | the air temperature at which precipitation falls as snow |
| · | heat exchange properties of the snow surface |
| · | study area elevation, latitude, and longitude correction. |
See … Read the rest
| Using Add-In Tools |
SWMM 5 has the ability to launch external applications from its graphical user interface that can extend its capabilities. This section describes how such tools can be registered and share data with SWMM 5.
| Tools Menu |
The Tools Menu contains commands used to configure … Read the rest
| Working with Objects |
SWMM uses various types of objects to model a drainage area and its conveyance system. This section describes how these objects can be created, selected, edited, deleted, and repositioned.
| · | Types of objects |
| · | Adding objects |
| · | Selecting an object |
| · | Moving an object |
| Flow Routing |
Flow routing within a conduit link in SWMM is governed by the conservation of mass and momentum equations for gradually varied, unsteady flow (i.e., the Saint Venant flow equations). The SWMM user has a choice on the level of sophistication used to solve these equations:… Read the rest
| Climatology |
The Climatology object in EPA SWMM describes the following climate-related variables used for computing runoff and snowmelt:
| · | Temperature |
| · | Evaporation |
| · | Wind Speed |
| · | Snowmelt |
| · | Areal Depletion |
| · | Climate Adjustments |
| Rain Gages |
Rain Gages supply precipitation data for one or more subcatchment areas … Read the rest
| Aquifers |
Aquifers are sub-surface groundwater zones used to model the vertical movement of water infiltrating from the subcatchments that lie above them. They also permit the infiltration of groundwater into the drainage system, or exfiltration of surface water from the drainage system, depending on the hydraulic gradient … Read the rest
| Non-visual Objects |
In addition to physical objects that can be displayed visually on a map, SWMM utilizes several classes of non-visual data objects to describe additional characteristics and processes within a study area.
| · | Climatology Data |
| · | Hydrology Data |
| · | Hydraulic Data |
| · | Water Quality Data |
| Links |
Links are the conveyance components of a drainage system and always lie between a pair of nodes. Types of links include:
| · | Conduits |
| · | Pumps |
| · | Regulators |
| Conduits |
Conduits are pipes or channels that move water from one node to another in the conveyance system. Their … Read the rest
| Nodes |
Nodes are points of a conveyance system that connect conveyance links together. There are several different categories of nodes that can be employed:
| · | Junctions |
| · | Outfalls |
| · | Flow Dividers |
| · | Storage Units |
Nodes are also the points where external inflows can enter a drainage system … Read the rest
| Water Quality Modeling Features |
In addition to modeling the generation and transport of runoff flows, SWMM can also estimate the production of pollutant loads associated with this runoff. The following processes can be modeled for any number of user-defined water quality constituents:
| · | dry-weather pollutant buildup |
| Main Menu |
The Main Menu located across the top of the SWMM main window contains a collection of menus used for working with the program. These include:
| · | File Menu |
| · | Edit Menu |
| · | View Menu |
| · | Project Menu |
| · | Report Menu |
| · | Tools Menu |
| Hydrologic Modeling Features |
SWMM accounts for various hydrologic processes that produce runoff from urban areas. These include:
| · | time-varying rainfall |
| · | evaporation of standing surface water |
| · | snow accumulation and melting |
| · | rainfall interception from depression storage |
| · | infiltration of rainfall into unsaturated soil layers |
| · | percolation |
| Files Used by SWMM |
This section describes the various files that SWMM can utilize. They include:
| · | Project File |
| · | Report and Output Files |
| · | Rainfall Files |
| · | Climate File |
| · | Calibration Data Files |
| · | Time Series Files |
| · | Interface Files |
The only file required to run … Read the rest
| LID Control Editor |
The LID Control Editor is used to define a low impact development control that can be deployed throughout a study area to store, infiltrate, and evaporate Subcatchment runoff. The design of the control is made on a per-unit-area basis so that it can be … Read the rest
| Project File |
A SWMM Project File is a plain text file that contains all of the data used to describe a study area and the options used to analyze it. The file is organized into sections, where each section generally corresponds to a particular category of object … Read the rest
| Printing and Copying |
This section describes how to print, copy to the Windows clipboard, or copy to file the contents of the currently active window in the SWMM workspace. This can include the Study Area Map, a graph, a table, or a report.
| · | Selecting a printer |