Goodbye By-Hand

June 9, 2008
An Illinois engineering firm finds improved design efficiency in a new storm water modeling solution

About the author: Douglas White, P.E., is project manager for Greengard Inc. White can be reached at 847.634.3883 or by e-mail at [email protected].


Over the past 50 years, the landscape of suburban Chicago has changed dramatically as the metropolitan area has grown. Since 1952, Greengard Inc. has been deeply involved in the area’s expansion, providing engineering services for residential, commercial and industrial land development.

The firm’s projects frequently involve storm water management, requiring design based on each county’s specifications. Over the years, the Greengard staff has tried numerous storm water modeling programs, but all have lacked the flexibility and capabilities needed. The engineers resorted to designing storm water projects using the Illinois Department of Transportation pipe-slope methodology with manual calculations and a series of Microsoft Excel spreadsheets—a time-consuming, error-prone approach.

Because data was built into individual cells in Excel files, engineers could not necessarily see full equations. Without that big-picture view, the firm risked undersizing pipes. The manual process led the engineers to again seek a more powerful modeling application.

Integration & Automation

While exploring different modeling solutions, the engineers came across StormNET by Boss Intl. The fully dynamic hydrology and hydraulic model analyzes simple and complex storm water systems using a variety of methods and models, including water quality.

The software integrates with the firm’s Autodesk Civil3D and Land Desktop programs, which means engineers do not need to draw elements twice. It also imports all the element properties (i.e., pipe diameters, pipe inverts, manhole inverts and rim elevations), greatly speeding up the modeling process.

The new modeling solution provides hydraulic gradeline design, which staff anticipated would result in more efficient storm water networks. Furthermore, the ability to model with smaller pipes significantly cuts clients’ project costs for storm water construction.

In-House Efficiency

Greengard engineers have found it simple to bring in pipe network drawings from Autodesk Civil3D and add junctions for manholes and pipes. Staff does not have to draw manholes or pipes twice—all the information from the pipe network is there when imported.

If the engineers change anything in a storm water network while in Civil3D, they re-import the storm water network back into StormNET, which updates the model with the new changes (i.e., elevations and pipe sizes).

Most often, Greengard uses the Rational Method and switches between storm scenarios as needed for projects. Engineers can click one button to switch between a 10-year and 100-year storm. Before, many changes had to be made on two different spreadsheets to change a storm event.

The modeling software’s graphical aspects allow Greengard engineers to see the impact of changes immediately. They can view water filling up pipes and see how a detention pond interacts with a storm sewer. Before, detention ponds were never in synch with storm sewers. It is helpful seeing how high a pond becomes in relation to a storm sewer for the design event in a project.

The engineers can also show designs to clients and municipal engineers, either on-screen in the office or as graphical printouts. Likewise, modeling enables them to demonstrate the viability of designs to project managers. Managers had previously reviewed Excel spreadsheets and checked calculations. It is also easier to prove to a project manager that a design works. A StormNET user clicks “Play” and the manager can see the model, reducing review time from two hours to 30 seconds.

Client Benefits

Greengard has seen the impact of more efficient modeling on a couple of projects. Staff designed a storm sewer to handle a 100-year storm event for a project in West Chicago, Ill., and found it helpful to switch between different storm events and arrive at the ideal pipe size. The final result comprised smaller pipe sizes than could have been achieved using the firm’s previous manual process, saving the client money.

Greengard also found that the software has contributed to design efficiency on a project with small slopes where there existed little room with which to play. Engineers could quickly and easily see and change the cover pipes to know whether the slope would work. As a result, the project required significantly less time than it would have before.

The newly implemented software cuts design revision time in half, if not more, allowing the firm to deliver projects sooner and minimize client costs by about 15 percent, according to Greengard staff.

The quicker design is done, the faster plans are reviewed, the faster clients can break ground, the less money the client is spending on taxes each month and the sooner they can begin making money on their development. In this business, a week means a great deal, a month is huge and three months can determine whether a project gets done before the winter.

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