US 20 Over Stoner Ditch in LaGrange County Gets Makeover
In 2018 LFA was asked to look for alternatives on a small structure replacement project regarding Stoner Ditch under US 20 in LaGrange County.
The existing structure was a 48-inch CMP corrugated metal pipe in poor condition. The original was built in 1964 and upgraded in 1986. It had become hydraulically inadequate to handle the storm water runoff of Stoner Ditch.
The hydraulic inadequacy of the structure was causing drainage issues upstream. This project was developed through a two tier approach first involving an Engineering Assessment process with an inventory of environmental considerations.
LFA recommended three alternatives for replacement with class 1 riprap placed at the outlet to protect the structure from scour. The preferred alternative was a sumped, 72-inch Reinforced Concrete Pipe. The replacement pipe was lengthened to better accommodate roadside safety with safer embankment side slopes.
Steady flow through the structure indicated dewatering and bypass pumping were required at this location during construction and documented through a Section 401 Water Quality Certification from IDEM and a Section 404 permit from the U.S. Army Corps of Engineers.
The project was completed in one phase under a complete closure with an official US 20 detour under a compressed construction schedule.
The project was completed in 2022 and now provides and structurally sound and hydraulically adequate replacement culvert addressing Stoner Ditch and US 20.