Over the years raSmith had completed numerous stormwater and floodplain analysis and design projects for the City of Oak Creek. As such, City officials knew who to turn to when floodwaters up to two feet deep were inundating Weatherly Drive. Both access roads to a residential subdivision were overtopped, providing limited access during flood events.
To avoid increasing flood stages upstream, it was necessary to provide enough capacity for flood flows while maintaining a wider than normal floodway. A 900-foot section of roadway was raised 6.5 feet to elevate the roadway above the flood stage. The final design included a 52-foot-long Conspan precast structure over the North Branch Oak Creek and twin 8-foot by 5-foot box culverts in the floodplain overbank. This Conspan structure is the largest constructed to date in the state of Wisconsin.