The Olmsted Dam on the Ohio River is currently under construction 16 miles upstream from the confluence with the Mississippi River. It will consist of an 800-foot-long tainter gate section, a 1,400-foot navigable pass, two boat abutment sections, a fixed weir section, and upstream and downstream scour protection.

In 2002, the Jacobs/Gerwick JV completed the design of the dam, an engineering challenge for several reasons:
a) Its proximity to the New Madrid Fault could impose a seismic event on the structure, which is located in an area of potentially liquefiable alluvium.
b) Maintaining vessel traffic along the river and accommodating fluctuating river elevations between 30-40' annually, and as much as 60' in a 100-year period.
c) Designing for the scour and uplift forces of artesian ground water and preserving a wildlife sanctuary on the Southern shore at the dam site.

Gerwick provided several construction alternatives for consideration. An in-the-wet method utilizing a catamaran to place large precast shell elements onto pile foundations was selected over the in-the-dry method, which would have required constructing the dam using two or three stages of traditional, fixed cellular sheetpile cofferdam techniques.

In 2004, the dam construction contract was awarded to a JV of Washington Group (URS)/Alberici. Gerwick has been working with the USACE and Contractor to design the construction equipment/methods that will allow the concrete shells to be moved from the precast yard to the river. Shells were built in the precast yard on casting slabs. The units are being lowered down a skidway into the Ohio River by push-pull units, at which point a catamaran lifts the frame/shell from the cradle and transports it to its final position. The 5,500-ton catamaran lifts the frame/shell from the cradle and carries the partially submerged shell to its final location in the river, where it will be set-down and connected to pre-driven pipe piles with tremie concrete.