Lincoln Memorial Avoids Flooding With Stormwater Engineering Software

The Lincoln Memorial in Washington, D.C., attracts millions of visitors each year and is one the most high profile landmarks in the United States. When it came time to rehabilitate the surrounding stormwater system, StormCAD® was the choice for CH2M Hill and the Eastern Federal Lands Highway Division of the United States Department of Transportation (USDOT).

Built between 1914 and 1922 as a memorial to U.S. President Abraham Lincoln, the structure sits on reclaimed swamp land at the west end of the mall and is a prominent gathering place not only for tourists, but also for special events. As the size of crowds and events around the memorial has grown, it has become imperative to update the surrounding Lincoln Circle and its approaches.

This $5-10 million construction project includes storm drainage improvements, replacement of all curbs, and new inlets as well as road rehabilitation, signalization, and safety improvements.The design of the storm sewer portion of the project was completed by CH2M Hill using StormCAD and MicroStation. Michelle Humowiecki, staff civil engineer at CH2M Hill explains, "We needed a storm sewer design package that was flexible, easy-to-use, and powerful. StormCAD filled all of these needs for us."

Engineers began by performing an analysis of the existing system. Using a DXF background image, calculated watershed areas, and surveyed invert data, they were able to quickly build a model of the system in StormCAD. Scenarios were then set up for various design rainfall events to replicate the conditions in the field.

Once the initial analysis was developed and running, they were able to identify where the existing system was over capacity and required larger or additional pipes and inlets. Using color coding, annotation, and profiles, they then were able to target the specific areas and prioritize their design work. This model, originally set up for system analysis, then became the base model for the design work.

StormCAD's user-friendly environment also allowed them to "roll with the punches" much more easily as the other portions of the design changed. Humowiecki added, "As the roadway design changed, it was easy to adjust StormCAD to reflect the drainage impacts, which saved us valuable time on the design."

Humowiecki also used StormCAD's inlet library to help tackle the inlet design. The site fell under the jurisdiction of two different governing bodies: the northern area drained into the Constitution Avenue combined sewer line, under the jurisdiction of the D.C. Water and Sewer Authority, and the southern area drained into the Potomac River, governed by the Chesapeake Watershed Commission. Each governing body required different inlet designs.

Although StormCAD did not by default have the exact inlets required for the project, by using the inlet library editor "it was easy to define inlet characteristics, such as dimensions, grate widths, etc., for this specific project," she said.

Another time-saver for the group was the automatic generation of HGL profile plots. In the past, when spreadsheets or other software had been used, it was necessary to manually plot these profiles for each of the design iterations. StormCAD reduced this to a few clicks of the mouse. The profile HGL plot from StormCAD was submitted directly to USDOT.

Recently, Haestad Methods announced its latest version release of StormCAD software for stormwater engineering. Version 5.0 builds upon the solid foundation established with previous versions of StormCAD, offering engineers a complete approach to storm sewer design and analysis.