Case study | Water Resources
US 67 Delhi Bypass
Details
Owner
Illinois Department of Transportation
Client
Chastain & Associates, LLC
Project Cost
Unknown
Status
Completed 2019
Summary
Kaskaskia Engineering Group, LLC (KEG) was contracted by Chastain & Associates, LLC to provide Hydraulic Analysis and Transportation Engineering services for the realignment of US 67 (ADT 11,200) near the unincorporated community of Delhi, in Jersey County, Illinois. The project included the construction of roughly 2.6 miles of new roadway, including a new culvert crossing over an Unnamed Tributary to Little Piasa Creek. The new structure is a double 8’ x 8’ reinforced concrete box culvert similar to the existing structure, which is to remain in place.
Project
KEG performed detailed hydraulic modeling of the existing creek and the proposed structure to confirm the selected size and configuration. The analysis included the use of the USACE HEC-RAS program and utilized USGS StreamStats to generate peak flood volumes. The flowline of the creek in the vicinity of the proposed project was unusually steep for a rural Illinois waterway, which required both subcritical and supercritical flow regime analysis to accurately model the hydraulic conditions and the resulting flood profile. A full hydraulic report was prepared per the requirements of the IDOT Drainage Manual and was submitted for IDOT approval.
In addition to the hydraulic portion of the project, KEG’s transportation group was tasked with developing the Maintenance of Traffic (MOT) Plans for the construction phase of the project. Traffic will remain on existing US 67 during the construction of the new roadway, but Delhi Road will be bisected by the new alignment. KEG was responsible for maintaining traffic on this rural roadway while the new highway is constructed and traffic is eventually transferred over to the new roadway.