StormCAD

Evaluation of Drainage Management Software

The following sections outline the input requirements, computational methods and output options available with this software. The package was run through various tests for comparison with MTO drainage management practices provided by the MTO Drainage Management Manual (1997). A summary of out results and the requirements for using this software for MTO design, analysis or approvals is provided.

Model Capabilities:

Functionality:

Use in MTO Drainage Management Practices:

Summary Evaluation



Model Capabilities

What does it do?

StormCAD is a tool for the design and analysis of storm sewer systems. The model assumes uniform flow and can account for supercritical and subcritical flow.

The program considers all gradually varied flow profiles: horizontal, mild, critical, steep and adverse slope, in combination with the subcritical, critical, and supercritical types of flow.

The program provides additional design functionality through a constraint based design option. With this option the user inputs constraint parameters such as max. /min. velocity, slope, and cover. The user can also specify to match pipe inverts or soffits at each node. The program will automatically determine the pipe sizes and inverts to satisfy these constraints.

How does it do it?

The user draws the sewer system connectivity on screen (either schematically or to scale). Data defining the sewer system inlets, pipes, junctions and outlets is then entered through a series of input tables/windows. The data requirements are generally equivalent to what is needed to perform the calculations by hand, however some data is calculated automatically. The following methodologies are used by the program during computations;

Hydrology: Inlet discharge can be input by the user as a combination of contributing watershed flow, external watershed flow, additional flow, carry over or a known flow. Peak flow estimates for the contributing watershed are performed using the Rational Method. Rainfall Data can be input as IDF curve equations or tables. Alternately, the program can calculate rainfall tables based on National Weather Service Hydro-35 method (Not applicable in Onatario).

Hydraulics: StormCAD can use several variations of the general uniform flow equation to calculate the frictional factor, i.e.: Manning's equation, Kutter's Formula, Hazen-Williams Formula and Darcy-Weisbach Formula. It is up to the user to decide which equation to use. The model considers all gradually varied flow profiles: horizontal, mild, critical, steep and adverse slope, in combination with the subcritical, critical, and supercritical types of flow.

Design: Constraint based design is possible. The model can automatically design a system based on constraint parameters provided by the user. Parameters such as maximum and minimum velocity, slope, and cover can be set. The user can also specify to match pipe inverts or soffits at each node. Automatic design will determine the pipe sizes & invert elevations. The model gives warnings if any of the above parameters are violated.

File Management

A project file is saved as a StormCAD file (*.stm). The naming of the file is only restricted to 8 characters with the format that is acceptable to DOS.

The program allows full access to all the output data. The output data tables can either be printed or exported as *.txt files. The network profiles can be printed or exported as *.dxf files. AutoCAD can only extract the layout and the layers from the *.dxf files exported from StormCAD. The attributes (such as pipe size, elevation, etc) do not get exported.

It is possible to import *.dxf files as background. The imported background cannot be manipulated.

Output Options

Summary reports including input parameters and analysis results can be printed for each inlet, junction, pipe or outlet. Tabular output can also be printed for each element or any combination of elements. Plan views can be printed of the entire system. Profiles views can be generated for any series of elements.

As well the following files can be exported:

Network Profile
Schematic Network Layout as *.DXF
Combined Pipe/Node Report
       DOT Report
Node Report
Pipe Report

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Functionality

Experience Required

A basic knowledge of culvert hydraulics and hydrology is required to interpret results and to ensure the calculation methods used in the program are applicable to the scenario being modelled.

Navigation of the program requires basic familiarity of windows based programs.

Using the program

Installing:
Instructions give just enough information to launch the setup program. The setup program is self -explanatory and takes approximately 2-3 minutes.

Learning:
The program provides a "One minute tutorial" which is useful to those unfamiliar with PC's/Windows in general and shows the basic features of the program, providing enough information to get started. On line help is easy to use, is often context sensitive and provides detailed information on using the program and theories and equations used.

Using: The program is laid out logically and navigation is easy. Error notification is given for some, but not all, bad input and is usually fairly clear. It is relatively easy to find answers to most questions using the on line help. The amount of data entry required is minimal. Run time for performing analysis is insignificant. Numerous plots, tables and reports are available to view results. Results can be printed or exported to other programs.

Comparison to Previous Version

There are no previous versions of StormCAD

General Considerations

The following notes should be considered as appropriate when using this program on MTO projects or projects requiring approval by MTO.

  • The model uses only imperial numbers in the calculation. There are metric values accompanying the corresponding imperial values for pipe configurations in the MATERIAL.INI file, but they are only for display in the program, and are only rough conversions. However, it is possible to change the imperial values to more precise figures.

  • StormCAD can import .dxf files as background, but it can not be manipulated within the program. When exporting the layout as .dxf file, no parameters or attributes get imported along with the file. AutoCAD, however, identifies the blocks and annotations, separating them into different layers.

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Use in MTO Drainage Management Practice

Overall, the use of this model is acceptable by MTO. The optional methods for calculations offered in the program include those covered in the MTO Drainage Management Manual.

Minimum Requirements for Inclusion in Report

This section provides some guidance to designers, analysts and reviewers on the type of information and minimum requirements for reporting the results of a StormCAD analysis. This by no means should be considered a comprehensive list of the information included in a drainage report.

Summary of input parameters

A summary of input parameters and computational methods chosen needs to be provided. Most of this information is included in the Detailed Reports generated by the program.

A summary of which computational methods were used for rainfall simulation and discharge estimation should be included as well as the source of coefficients. Any variance from accepted practise should be explained.

Tabular and Graphical Output

The report should include both tabular combined reports and graphical output showing the plan view of the system and profile views of the design. Profile views should include HGL, invert elevations, ground elevations as a minimum. Any other variables pertinent to the report's recommendations should also be supported by tabular and graphical output.

Customized Files

To make additional material selection and configuration, the MATERIAL.INI file can be edited. Refer to StormCAD Help; search with keywords "material, component" for procedures.

StormCAD provides a limited list of pipe sizes that are used in the analysis. For this reason an MTO customized pipe size file was created. You need to download this file to the StormCAD directory to gain access to the additional pipe sizes.

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Summary Evaluation

Go to the HTML version of the Summary Evaluation of CuvertMaster, or download the PDF version (44 KB)

To view PDF files, you will require Adobe Acrobat Reader.

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Definitions

IDF curve:

Intensity-Duration-Frequency curves (or tables) provide the rainfall intensities corresponding to specified durations and frequencies of occurrence of rainfall events.

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