DEM - Digital Elevation Model

A digital elevation model (DEM) is a digital representation of ground surface topography or terrain. It is also widely known as a digital terrain model (DTM). A DEM can be represented as a raster (a grid of squares) or as a triangular irregular network. DEMs are commonly built using remote sensing techniques, however, they may also be built from land surveying. DEMs are used often in geographic information systems, and are the most common basis for digitally-produced relief maps.

Production

Digital elevation models may be prepared in a number of ways, but they are frequently obtained by remote sensing rather than direct survey. One powerful technique for generating digital elevation models is interferometric synthetic aperture radar; two passes of a radar satellite (such as RADARSAT-1) suffice to generate a digital elevation map tens of kilometers on a side with a resolution of around ten meters. One also obtains an image of the surface cover.

Another powerful technique for generating a Digital Elevation Model is using the digital image correlation method. It implies two optical images acquired with different angles taken from the same pass of an airplane or an Earth Observation Satellite (such as the HRS instrument of SPOT5).

Older methods of generating DEMs often involve interpolating digital contour maps that may have been produced by direct survey of the land surface; this method is still used in mountain areas, where interferometry is not always satisfactory. Note that the contour line data or any other sampled elevation datasets (by GPS or ground survey) are not DEMs, but may be considered digital terrain models. A DEM implies that elevation is available continuously at each location in the study area.

The quality of a DEM is a measure of how accurate elevation is at each pixel (absolute accuracy) and how accurately is the morphology presented (relative accuracy). Several factors play an important role for quality of DEM-derived products:

• terrain roughness;
• sampling density (elevation data collection method);
• grid resolution or pixel size;
• interpolation algorithm;
• vertical resolution;
• terrain analysis algorithm;

Stormwater Software - RMA 2

RMA2 is a hydrodynamic modeling code that supports subcritical flow analysis, including wetting and drying and marsh porosity models. It is part of the TABS analysis package written by the U.S. Army Corps of Engineers Waterways Experiment Station (USACE-WES). The methods of analysis used by the TABS codes along with their file formats and input parameters are described in their own documents. SMS supports both pre- and post-processing for RMA2.A mesh for use with RMA2 is created and edited in SMS using the Mesh Module. The modeling parameters required by RMA2 are generated and applied to the mesh using commands grouped in the RMA2 menu. Post processing of solution data generated by RMA2 is done using the generic visualization tools of SMS

Stormwater Software - MUSIC

Taken from http://www.ecosol.com.au/music.asp


MUSIC Stormwater Management System

Introduction to MUSIC

MUSIC is an acronym for Modelling Software for Urban Stormwater Improvement Conceptualisation. It is a product of the Cooperative Research Centre for Catchment Hydrology (now eWater CRC) and the licensor is Monash University.

MUSIC provides a user-friendly decision support system that enables planners to evaluate conceptual designs of stormwater management systems to meet water quality objectives for their catchment and requirements with respect to water-sensitive urban design.

MUSIC allows complex stormwater management scenarios to be quickly and efficiently created and the results to be viewed using a range of graphical and tabular formats. This reduces the uncertainty surrounding the planning of stormwater management strategies, and may generate substantial cost-savings.

To use MUSIC you need to register and pay a fee (currently $330) to download the software. Training and support is provided by the eWater CRC.

Purpose

MUSIC is designed to simulate urban stormwater systems operating at a range of temporal and spatial scales for catchments from 0.01km2 to 100km2 and modelling time steps ranging from 6 minutes to 24 hours to match the catchment scale.

Target user

MUSIC is designed for urban stormwater engineers, planners, policy staff, consultants as well as state, regional, and local government authorities. An understanding of stormwater management principles and practices is required to use MUSIC.

Application of MUSIC to modelling GPTs

Double clicking a GPT icon within MUSIC produces a popup window that requires the following data to be input:
1. low flow bypass;
2. high flow bypass; and
3. piecewise-linear user-definable transfer functions for the GPT performance in capturing Gross Pollutants (GP), Total Suspended Solids (TSS), Total Phosphorus (TP), and Total Nitrogen (TN). In each case the independent variable is input concentration (mg/l or kg/MI) and the dependent variable is the output concentration.

The GPT inputs are independent of the flow rate, except that there are underflow and overflow limits. Flow below the underflow limit, and flow above the overflow limit, passes through with no change of concentration.

Important consideration for MUSIC user

The validity of the predictions is only as good as the validity of the input data. All GPT performance predictions are subject to uncertainty owing to the stochastic nature of environmental processes, with quantities varying chaotically with time and location. The difficulty in making repeatable measurements is illustrated in the wide range of published test results. This is not surprising considering that there can be significant differences, for example in the:

• catchment type and hydrology;
• weather conditions and events during the testing period;
• sampling regimes – frequency, timing, and location;
• composition of pollutant load;
• nutrient transport mechanisms;
• level of bonding of nutrients to suspended solids
• degradation of accumulated pollutants;
• suspended solid particle size distribution (PSD); and the size and state of the unit (i.e. how well it has been cleaned and maintained).

Consequently, when comparing different GPTs, it is important to understand that the results may have been derived in conditions that vary significantly. There is no industry-wide standard for determining the input values required by MUSIC.

Capture Efficiency of Nutriens (TP and TN)

GPTs capture are designed primarily to capture solid particles but, because they attach to these particles, nutrients are also captured. This is measured in terms of TSS capture efficiency. It follows then that GPTs with the same TSS performance will remove the same level of nutrients as along as all other conditions are the same.

The most comprehensive measurement of GPT nutrient capture in Australia was reported in Walker et. al. 1991, a document referenced in Appendix C3 of the MUSIC development team, CRC for Catchment Hydrology (revised February 2005 for MUSIC v2.1). This documents quotes “approximately 30%” TP removal and also found that although TN removal was erratic during storm events, there was “consistent removal of approximately 13% of TN during dry weather flow conditions”.

The MUSIC input data must be viewed as an overall long-term average – in the short term there are simply too many fluctuations making any conclusions largely meaningless. The long-term pollutant capture performance depends not only on the make and type of GPT but how it is managed and maintained.

If inappropriate pollutant removal practices are used to clean the GPT (such as clamshell or removable basket, where much of the sediment is returned to the unit through draining and then subsequently remobilised), it is obvious that claimed nutrient removal rates will be reduced significantly. This is one of the most significant benefits from using the vacuum method, which ensures that all pollutants are removed form the unit.

Recommendations for MUSIC input values for Ecosol units are provided at the bottom of each product page. Click for RSF 100, RSF 1000 and RSF 4000.

Stormwater Software - 12D

Taken from http://www.12d.com/

Established in 1988, 12D Solutions sells and supports its principal product suite, 12d Model (formerly known as 4d Model) direct and through distributors around the world.

12D Solutions clients include civil and water engineering consultants; environmental consultants; surveyors; local; state and national government departments and authorities; research institutes; construction companies and mining consultants.

12d Model is a powerful terrain modelling, surveying and civil engineering software package. It allows fast production in a wide variety of projects including roads, rail, site layouts, and environmental impact studies.

12d Model is a powerful terrain modelling, surveying and civil engineering package. It allows fast production in a wide variety of projects including roads, site layouts, subdivisions and Environmental Impact studies.

Using 12d Models screen menus and fast interactive graphics, the user effortlessly moves through a design.

With 12d Models powerful design capabilities, difficult surveying and civil design tasks can be easily visualized and completed.

Projects such as roads, channels, storage tanks, subdivisions, landscaping, rail studies, major pipelines, waste water reticulation and general site works are efficiently handled with 12d Model.

12d Model includes a powerful programming language which allows users to build their own options from 12d Models extensive programming library.

12d Model features data exchange with drainage and river analysis packages including XP-SWMM, XP-UDD, Drains, ILSAX, PC Drain, RATHGL and HEC-RAS, survey packages such as TP Setout as well as the CAD systems IntelliCAD, AutoCAD and Microstation.

12d Model is a totally Australian product, running on Windows NT, 95, 98, 2000 and XP (including PC Notebooks).

12d Model has been specifically designed for easy use. It is ideal for use at all stages of projects, and is particularly useful for large route selection and corridor studies.12d Model is an essential tool in today's fiercely competitive business climate.

Rivers

There are six modules for rivers work: HEC RAS Advanced, XP SWMM, Mike 11, UNET and ISIS.

These modules create the natural cross section files for HEC RAS, XP-SWMM, XP-UDD, Mike11, UNET and ISIS respectively. The water level results from these packages can then be read back into 12d to create a detailed water surface that accurately defines the river bank between the defined cross sections. This water surface is used to create 3d images, movie files of flight or walks down the river, cross section plots. river profiles and plan drawings coloured and contoured by depth.

Historical flood data can also be presented in 12d Model using the "river mapper". This interface creates a water surfaces from existing water level data. The interface uses "shape strings" to add incredible power and flexibility to the mapping process. Meandering streams and off line storages can easily be mapped without burdening your hydraulic modelling package with additional cross section calculations.

The 12d Model Rivers modules read numerous data formats including HEC2 data, EEBY cross section data, USGS DEM formats and xyz data. The add on AutoCAD DWG/DXF and Microstation DGN modules enable existing drawing/elevation data to be imported to 12d.

Elevation data can be combined from several sources and manipulated to form a final ground surface from which cross section data is created.

The modules generate cross sections, measure channel and overbank distances, mark left and right bank locations and automatically mark levee locations for HEC RAS. User specified steady state discharges and Manning's "n" values are exported as initial starting values.

Raster georeferenced images (which can exceed one gigabyte in size) can be used as backdrops for defining your river bank locations. For simple projects, channel improvements are easily designed and volumes calculated using 12d Model Base. Complex designs and volumes may require other modules.

The Rivers modules are:
HEC RAS Advanced, XP SWMM & MIKE 11

These river interface modules work on branched river systems. The complete project is created for the river design programs and for unsteady flow conditions. The maximum water levels are read back into 12d Model.

UNET
In addition to cross section data, this module also exports reservoir storage areas.

ISIS
ISIS has the most comprehensive interface of the Rivers modules. Volumes for online and offline reservoirs are exported and cross sections are created for spill sections as well as river cross sections.

Urban Drainage

The Drainage module allows the design of drainage networks, typically those required for new land subdivisions and development projects.

The drainage string itself consists of manholes, joined by straight or curved pipes. Invert levels and pipe grades can be set or modified graphically or by typed input. Manhole and pipe sizes are also user definable.

Drainage design can be as simple or complex as the project dictates. 12d automatically determines pipe grade based on minimum slope and cover while services clashes are displayed graphically. Data is exported to the design packages Drains, PCdrain, XP-SWMM, XP-UDD, RAT2000, RATHGL, ILSAX, WINDES (Micro Drainage) and spreadsheets. The data exported can be as simple as catchment areas or as advanced as pit inlet capacity and overland flow (determined inside 12d by measuring road cross fall and grade). Even maximum ponding levels and volumes can be determined for inlet in SAG inlet conditions.

Results from the design packages can be read back into 12d enabling the user to....

• update 12d with the new inverts and pipe sizes from the drainage design software.
• plot customised drainage long sections with service crossings, hydraulic grade line, flow, velocity and/or user defined data. Services that cross the drainage pipe and those within a user defined corridor (parallel to the pipe) are also included.
• plot customised plan drawings indicating catchments, pipe sizes and types, inverts and more.
• print pit construction schedules in predefined or custom formats.
• produce pit/pipe quantity schedules by pipe sizes, depths, types etc (all custom defined).
  detailed excavation volumes reflecting pipe sizes, over excavation for bedding materials and user defined trench shapes. Volumes by depth can then be calculated using the 12d volumes package.
• calculate and display/plot flooded areas from overflow volumes or overland flow discharges (normal depth calculations).
• create HEC RAS project files for detailed backwater calculations in critical areas.

Sewer - Waste Water Reticulation

The Sewer module is an extension of the Drainage module and supports the design of gravity operated waste water reticulation systems, typically those required for new land subdivisions (estates) and development projects.

The user enters proposed manholes, pipelines and end of line points. Obstructions which pass over, under or parallel to the design lines within a user specified corridor about the design line will be shown on long and cross section views.

When satisfied with the design invert levels, connections from the design line to the individual house blocks can be added and reported on.Earthwork volumes for trenches can be calculated along the selected design line.

The special waste water reticulation longitudinal plots show existing surface, manholes, design pipelines, pipe grades, property connection points and all obstructions. Long section plots to the Melbourne Water standard are included.

Pipeline

This module is used to support the design of major pipelines of any diameter (for example, 2000 mm) and any length.

The module allows for the extraction of long sections and cross sections against the digital terrain model for the proposed route, plus all the obstructions that run parallel to or cross a corridor of user given width on either side of the centre line of the route.

The joint deflection for pipes of a user nominated length is calculated and interactively displayed along the pipeline.

Earthwork volumes for trenches can be calculated along the selected design line.

The special pipeline longitudinal plots show the existing surface, design pipeline, depth of cut or fill to pipe invert, percentage grades and vertical curve data or deflection angles, and all obstructions.

Stormwater Software - HEC-HMS

Taken from http://www.hec.usace.army.mil/software/hec-hms/

The Hydrologic Modeling System (HEC-HMS) is designed to simulate the precipitation-runoff processes of dendritic watershed systems. It is designed to be applicable in a wide range of geographic areas for solving the widest possible range of problems. This includes large river basin water supply and flood hydrology, and small urban or natural watershed runoff. Hydrographs produced by the program are used directly or in conjunction with other software for studies of water availability, urban drainage, flow forecasting, future urbanization impact, reservoir spillway design, flood damage reduction, floodplain regulation, and systems operation.

The program is a generalized modeling system capable of representing many different watersheds. A model of the watershed is constructed by separating the hydrologic cycle into manageable pieces and constructing boundaries around the watershed of interest. Any mass or energy flux in the cycle can then be represented with a mathematical model. In most cases, several model choices are available for representing each flux. Each mathematical model included in the program is suitable in different environments and under different conditions. Making the correct choice requires knowledge of the watershed, the goals of the hydrologic study, and engineering judgment.

The program features a completely integrated work environment including a database, data entry utilities, computation engine, and results reporting tools. A graphical user interface allows the seamless movement between the different parts of the program. Program functionality and appearance are the same across all supported platforms.

Contents:

• Watershed Physical Description
• Meteorology Description
• Hydrologic Simulation
• Parameter Estimation
• Analyzing Simulations GIS Connection

Watershed Physical Description

The physical representation of a watershed is accomplished with a basin model. Hydrologic elements are connected in a dendritic network to simulate runoff processes. Available elements are: subbasin, reach, junction, reservoir, diversion, source, and sink. Computation proceeds from upstream elements in a downstream direction.

An assortment of different methods is available to simulate infiltration losses. Options for event modeling include initial constant, SCS curve number, gridded SCS curve number, exponential, and Green Ampt. The one-layer deficit constant method can be used for simple continuous modeling. The five-layer soil moisture accounting method can be used for continuous modeling of complex infiltration and evapotranspiration environments. Gridded methods are available for both the deficit constant and soil moisture accounting methods.

Several methods are included for transforming excess precipitation into surface runoff. Unit hydrograph methods include the Clark, Snyder, and SCS techniques. User-specified unit hydrograph or s-graph ordinates can also be used. The modified Clark method, ModClark, is a linear quasi-distributed unit hydrograph method that can be used with gridded meteorologic data. An implementation of the kinematic wave method with multiple planes and channels is also included.

Multiple methods are included for representing baseflow contributions to subbasin outflow. The recession method gives an exponentially decreasing baseflow from a single event or multiple sequential events. The constant monthly method can work well for continuous simulation. The linear reservoir method conserves mass by routing infiltrated precipitation to the channel.

A variety of hydrologic routing methods are included for simulating flow in open channels. Routing with no attenuation can be modeled with the lag method. The traditional Muskingum method is included along with the straddle stagger method for simple approximations of attenuation. The modified Puls method can be used to model a reach as a series of cascading, level pools with a user-specified storage-discharge relationship. Channels with trapezoidal, rectangular, triangular, or circular cross sections can be modeled with the kinematic wave or Muskingum-Cunge methods. Channels with overbank areas can be modeled with the Muskingum-Cunge method and an 8-point cross section.

Water impoundments can also be represented. Lakes are usually described by a user-entered storage-discharge relationship. Reservoirs can be simulated by describing the physical spillway and outlet structures. Pumps can also be included as necessary to simulate interior flood area. Control of the pumps can be linked to water depth in the collection pond and, optionally, the stage in the main channel.

Meteorology Description

Meteorologic data analysis is performed by the meteorologic model and includes precipitation, evapotranspiration, and snowmelt. Six different historical and synthetic precipitation methods are included. Two evapotranspiration methods are included at this time. Currently, only one snowmelt method is available.

Four different methods for analyzing historical precipitation are included. The user-specified hyetograph method is for precipitation data analyzed outside the program. The gage weights method uses an unlimited number of recording and non-recording gages. The Thiessen technique is one possibility for determining the weights. The inverse distance method addresses dynamic data problems. An unlimited number of recording and non-recording gages can be used to automatically proceed when missing data is encountered. The gridded precipitation method uses radar rainfall data.

Four different methods for producing synthetic precipitation are included. The frequency storm method uses statistical data to produce balanced storms with a specific exceedance probability. Sources of supporting statistical data include Technical Paper 40 and NOAA Atlas 2. While it was not specifically designed to do so, data can also be used from NOAA Atlas 14. The standard project storm method implements the regulations for precipitation when estimating the standard project flood. The SCS hypothetical storm method implements the primary precipitation distributions for design analysis using Natural Resources Conservation Service (NRCS) criteria. The user-specified hyetograph method can be used with a synthetic hyetograph resulting from analysis outside the program.

Potential evapotranspiration can be computed using monthly average values. There is also an implementation of the Priestley-Taylor method that includes a crop coefficient. A gridded version of the Priestley-Taylor method is also available.

Snowmelt can be included for tracking the accumulation and melt of a snowpack. A temperature index method is used that dynamically computes the melt rate based on current atmospheric conditions and past conditions in the snowpack.

Hydrologic Simulation

The time span of a simulation is controlled by control specifications. Control specifications include a starting date and time, ending date and time, and a time interval.

A simulation run is created by combining a basin model, meteorologic model, and control specifications. Run options include a precipitation or flow ratio, capability to save all basin state information at a point in time, and ability to begin a simulation run from previously saved state information.

Simulation results can be viewed from the basin map. Global and element summary tables include information on peak flow and total volume. A time-series table and graph are available for elements. Results from multiple elements and multiple simulation runs can also be viewed. All graphs and tables can be printed.

Parameter Estimation

Most parameters for methods included in subbasin and reach elements can be estimated automatically using optimization trials. Observed discharge must be available for at least one element before optimization can begin. Parameters at any element upstream of the observed flow location can be estimated. Six different objective functions are available to estimate the goodness-of-fit between the computed results and observed discharge. Two different search methods can be used to minimize the objective function. Constraints can be imposed to restrict the parameter space of the search method.

Analyzing Simulations

Analysis tools are designed to work with simulation runs to provide additional information or processing. Currently, the only tool is the depth-area analysis tool. It works with simulation runs that have a meteorologic model using the frequency storm method. Given a selection of elements, the tool automatically adjusts the storm area and generates peak flows represented by the correct storm areas.

GIS Connection

The power and speed of the program make it possible to represent watersheds with hundreds of hydrologic elements. Traditionally, these elements would be identified by inspecting a topographic map and manually identifying drainage boundaries. While this method is effective, it is prohibitively time consuming when the watershed will be represented with many elements. A geographic information system (GIS) can use elevation data and geometric algorithms to perform the same task much more quickly. A GIS companion product has been developed to aid in the creation of basin models for such projects. It is called the Geospatial Hydrologic Modeling Extension (HEC-GeoHMS) and can be used to create basin and meteorologic models for use with the program.

Stormwater Software - HEC-RAS

Taken from http://www.hec.usace.army.mil/software/hec-ras/

HEC-RAS allows you to perform one-dimensional steady flow, unsteady flow, sediment transport/mobile bed computations, and water temperature modeling.HEC-RAS is designed to perform one-dimensional hydraulic calculations for a full network of natural and constructed channels. The following is a description of the major capabilities of HEC-RAS.

1. User interface
2. Hydraulic Analysis Components
3. Data Storage and Management
4. Graphics and Reporting.

User Interface

The user interacts with HEC-RAS through a graphical user interface (GUI). The main focus in the design of the interface was to make it easy to use the software, while still maintaining a high level of efficiency for the user. The interface provides for the following functions:

• File Management
• Data Entry and Editing
• Hydraulic Analyses
• Tabulation and Graphical Displays of Input and Output Data
• Reporting Facilities
• Context Sensitive Help

Hydraulic Analysis Components

The HEC-RAS system contains four one-dimensional river analysis components for: (1) steady flow water surface profile computations; (2) unsteady flow simulation; (3) movable boundary sediment transport computations; and (4) water quality analysis. A key element is that all four components use a common geometric data representation and common geometric and hydraulic computation routines. In addition to the four river analysis components, the system contains several hydraulic design features that can be invoked once the basic water surface profiles are computed.

Steady Flow Water Surface Profiles.

This component of the modeling system is intended for calculating water surface profiles for steady gradually varied flow. The system can handle a full network of channels, a dendritic system, or a single river reach. The steady flow component is capable of modeling subcritical, supercritical, and mixed flow regimes water surface profiles.

The basic computational procedure is based on the solution of the one-dimensional energy equation. Energy losses are evaluated by friction (Manning’s equation) and contraction/expansion (coefficient multiplied by the change in velocity head). The momentum equation may be used in situations where the water surface profile is rapidly varied. These situations include mixed flow regime calculations (i.e. hydraulic jumps), hydraulics of bridges, and evaluating profiles at river confluences (stream junctions).

The effects of various obstructions such as bridges, culverts, weirs, and structures in the flood plain may be considered in the computations. The steady flow system is designed for application in flood plain management and flood insurance studies to evaluate floodway encroachments. Also, capabilities are available for assessing the change in water surface profiles due to channel improvements, and levees. Special features of the steady flow component include: multiple plan analyses; multiple profile computations; multiple bridge and/or culvert opening analyses; and split flow optimization.

Unsteady Flow Simulation.

Unsteady Flow Simulation. This component of the HEC-RAS modeling system is capable of simulating one-dimensional unsteady flow through a full network of open channels. The unsteady flow equation solver was adapted from Dr. Robert L. Barkau's UNET model (Barkau, 1992 and HEC, 1997). The unsteady flow component was developed primarily for subcritical flow regime calculations. However, with the release of Version 3.1, the model can now performed mixed flow regime (subcritical, supercritical, hydraulic jumps, and draw downs) calculations in the unsteady flow computations module.

The hydraulic calculations for cross-sections, bridges, culverts, and other hydraulic structures that were developed for the steady flow component were incorporated into the unsteady flow module.Special features of the unsteady flow component include: Dam break analysis; levee breaching and overtopping; Pumping stations; navigation dam operations; and pressurized pipe systems.

Sediment Transport/Movable Boundary Computations

This component of the modeling system is intended for the simulation of one-dimensional sediment transport/movable boundary calculations resulting from scour and deposition over moderate time periods (typically years, although applications to single flood events are possible).

The sediment transport potential is computed by grain size fraction, thereby allowing the simulation of hydraulic sorting and armoring. Major features include the ability to model a full network of streams, channel dredging, various levee and encroachment alternatives, and the use of several different equations for the computation of sediment transport.

The model is designed to simulate long-term trends of scour and deposition in a stream channel that might result from modifying the frequency and duration of the water discharge and stage, or modifying the channel geometry. This system can be used to evaluate deposition in reservoirs, design channel contractions required to maintain navigation depths, predict the influence of dredging on the rate of deposition, estimate maximum possible scour during large flood events, and evaluate sedimentation in fixed channels.

Water Quality Analysis

This component of the modeling system is intended to allow the user to perform riverine water quality analyses. An advection-dispersion module is included with this version of HEC–RAS, adding the capability to model water temperature. This new module uses the QUICKEST-ULTIMATE explicit numerical scheme to solve the one-dimensional advection-dispersion equation using a control volume approach with a fully implemented heat energy budget. Transport and Fate of a limited set of water quality constituents is now also available in HEC-RAS. The currently available water quality constituents are: Dissolved Nitrogen (NO3-N, NO2-N, NH4-N, and Org-N); Dissolved Phosphorus (PO4-P and Org-P); Algae; Dissolved Oxygen (DO); and Carbonaceous Biological Oxygen Demand (CBOD).

Stormwater Software - XP SWMM

Taken from http://www.xpsoftware.com.au/products/xpswmm.htm


xpswmm is a comprehensive software package for modeling stormwater, sanitary and river systems. xpswmm is used by scientists, engineers and managers to develop link-node (1D) and spatially distributed hydraulic models (2D). It simulates natural rainfall-runoff processes and the performance of engineered systems that manage our water resources.

xpswmm models are used for the analysis, design and operation of storm and wastewater systems. It also simulates flow and pollutant transport in engineered and natural systems including ponds, rivers, lakes, floodplains and the interaction with groundwater.

xpswmm is a dynamic unsteady flow model rather than a steady state or standard step model. Our program is therefore capable of delivering results far more accurately and closer to real life than a steady state model will be able to accomplish. Dynamic models allow the effects of storage and backwater in conduits and floodplains and the timing of the hydrographs to yield a true representation of the HGL at any point in space and time.

xpswmm simulates the complete hydrologic cycle in rural and urban watersheds. Beginning with single or multiple rainfall events and dry weather flows, it models flows through collection, conveyance and treatment systems to the final outfalls. All hydrologic processes including infiltration, temporary storage and ground-surface water exchanges are included in the model. The software provides a fast solution for analyzing the design of the most complex hydraulic networks including loops, tidal inflows, hydraulic structures, regulators, multiple time varying boundary conditions and distributed storage structures

xpswmm uses OLE and ODBC database connections to quickly exchange data to/from any existing hydraulic model, asset management database or GIS. Results can be displayed and animated in plan and profile views, organized into tables, charts, or even 3D AVI movies.

Typically, xpswmm is used for:





Stormwater Management

• Stormwater master plans


• Major/Minor or Dual Drainage Systems


• Watershed master planning


• 1D drainage network with 2D overland flow hydraulics


• Detention pond optimization

• Subdivision drainage

Sanitary and Combined Collection Systems

• Capacity analysis and collection system hydraulics
  
• CSO and SSO mitigation studies


• RDII Infiltration and Inflow studies

River Systems and Floodplain Management

• 1D and 2D River Hydraulic
  
• Identifying flood hazards


• Culvert and Bridge Analysis Generating flood maps
  

Key features within xpswmm include:

• GIS Integration - connect to OBDC compliant databases, import and display ESRI shape files and MapInfo files. The purpose of the GIS link is to facilitate the import and export of modeling data from GIS and other data sources such as spreadsheets, asset management software and OLE/ODBC compliant databases. It also allows the inclusion of shape files as background layers and the data to be viewed and manipulated in our productive XP graphical environment.

• Animations - review and present model results in customizable animations including dynamic long section, dynamic section views, dynamic plan view and the full 3-D perspective view. These animations offer an unparalleled visualization of model results.

• Scenario Manager - easy way to examine "what if" scenarios within a single project without the need of adding redundant data. Compare model results graphically and in tables for various scenarios. A specialized scenario management tool exists also for simulating multiple storms in a single run multiple storms

• p2D - this option allows you to model overland flows, street flooding and river floodplains using either a 1D - 2D integrated model or a complete 2D model.

• Real Time Control - allows the simulation of control (RTC) such as gates, valves, flow regulators, moveable weirs, and telemetry-controlled pumps. An optional RTC add-on module extends the RTC to a comprehensive management and design tool. It's sensors can be any combination of velocity, flow and water level at nodes, conduits, pumps, weirs or orifices in the network.

• EPA SWMM Compatibility - import EPA-SWMM version 5 and the earlier 4.X models

• FEMA Approval - xpswmm is approved by US Federal Emergency Management Authority (FEMA) under multiple categories and results are now accepted for steady state, unsteady state, hydraulic or hydrological applications.

• Hydrology Choices - choose from 14 hydrology methods including SWMM Runoff, SCS Laurenson, SBUH, Rational method, Sacramento methods, LA County Hydrology, and many others.

• Localization - customize the software such as the model's defaults, parameter precision and create and use templates. Many sample templates are provided that contain common data used for typical modeling applications or typical data for a municipality/regions.

• Quick Data View provides one-click access to your model data and results.

• Subsurface Hydrology - account for perched water tables and limited soil storage using groundwater options.

• Conduit Design - design for full, partial flow, pressure flow (minimum allowable freeboard), minimum cover, multiple cells and the ability to select from a list of available pipes sizes.

• xpviewer - distribute your model to stakeholders in a read only format. Model simulations, including all scenarios may be viewed with downloadable free software.

Here are some of the newest features of xpswmm:

A layer control panel has been added to aid in the management of modeling objects such as links, nodes, text, polygons and polylines and other graphical layers such as background graphics and the model tin.

xptables have been expanded to a full tabular reporting tool that allows such features as: grouping of columns with subheadings, font and color selection, text alignment and rotation, ability to create custom variables and conversion of the units. For example the presentation of the Lake depth in the image is the subtraction of the Invert Elevation from the Ground Elevation.

The addition of new modeling objects called Catchment Polygons. These polygons can be imported from GIS or drawn on the screen. The catchment polygon can be graphically attached to the node it drains to and the area of the catchment automatically associated to the subcatchment area for the node.

The DTM feature allows the user to import triangulate and display a surface TIN. This powerful tool enhances the modeling experience by allowing the user to directly and indirectly use the surface in building the model. For example moving the mouse on the TIN displays a X,Y and Z coordinates in the status bar and node ground elevations can be automatically assigned from the elevation of the surface model. DTM is now included with all new xpswmm licenses.

The storage/treatment capabilities that were previously only found in the Sanitary mode are now accessible in the Runoff node and subcatchment and also the Hydraulics mode. This means that the model can now simulate LID at the catchment level and regional BMP in all modes. For example the BMP option in a Runoff subcatchment may simulate the quantity and quality benefits of a rain garden or green roof. The resulting node by hydrograph has the outflow from the BMP which can then be combined with other flows that are eventually routed to a water quality control pond simulated in the Hydraulics mode.

The xp2D module option that can simulate overland flow from flooded manholes or flow in floodplains. A 2D hydrodynamic engine called TUFLOW has been incorporated to allow integrated 1D and 2D modeling.