4 Mile Low Water Crossing
US Army Corps of Engineers
Fort Sill, Oklahoma


Structural Design

Hydraulic Analysis and Modeling

Environmental Permitting

Government Agency Coordination

MacArthur Associated Consultants (MAC) was the Designer-of-Record on the Design-Build Team led by Diversified Construction for the 4-Mile Low Water Crossing over Medicine Creek at Fort Sill Army installation in Comanche County, Oklahoma.

In May 2015, the bridge was deemed unsafe because it sat two feet above the creek. The new crossing provides a safe route over the creek that can remain open during storms, guaranteeing Fort Sill training exercises are not impacted.

The project consisted of removal and replacement of the existing low-water crossing and culverts with a five cell 14’x20’ reinforced concrete box structure with wingwalls, headwalls and aprons supporting a 30-foot clear span driving surface. The upstream incorporated a weir structure with orifices at an equal size and elevation to the existing corrugated metal pipes to ensure the upstream wetlands were maintained. Design also included new concrete roadway to tie crossing to the existing road.