State Highway 3 Reconstruction and Relocation

St. Maries, Idaho

PROJECT OVERVIEW

In 1997, Welch, Comer & Associates, Inc. was selected as the prime consultant to ITD for reconstruction of S.H. 3 in Benewah County, Idaho. The reconstruction of S.H. 3 came about in response to the flooding that occurred in 1996, whereby the St. Joe River levee, supporting the highway, breached and flooded the airport, several residences and businesses, and many acres of land.

After the floods, the Corps of Engineers ordered Benewah County to raise the height of all levees in the area.  Damage to a 2.2 mile portion of S.H. 3 on the levee, and the COE order forced the reconstruction of the state highway. Welch-Comer provided civil engineering, design, surveying and project management, and teamed with a geotechnical engineering firm to design the new highway.  ITD supported the ER project by facilitating the environmental issues through the appropriate agencies and conducted the final right-of-way negotiations with property owners.

A corridor analysis performed by Welch-Comer identified a combination of levee and overland routes that would satisfy Federal and State design standards for 60 mph design speed.  Geotechnical investigation revealed saturated silts, clays, peat, and gravels, which led to unique and extreme solutions for stabilization of the roadway.  Incidental work included relocation of 24-inch and 8-inch sewer mains, construction of a new drainage district lift station, and complete relocation of telephone and electrical facilities.  In addition, Welch-Comer prepared special provisions and standard specification modifications, and construction cost estimates.

Welch-Comer also acted as liaison between ITD, Benewah County, City of St. Maries, and worked closely with other State agencies during the environmental approval process. The project was funded by FHWA as an Emergency Relief project, with construction costs of approximately $5.5 million. Welch-Comer prepared this project for bid in sixteen months, which is considered a short time frame for FHWA projects of this size.

KEY ELEMENTS

  • Corridor Analysis/Roadway Design
  • Geotechnical Solutions for Poor Soil Conditions/Foundations
  • Numerous Environmental Permit Requirements
  • Co-Management of Incompatible Uses - Levee vs. Roadway
  • Right-of-Way Acquisition (Federal Requirements)
  • MSE Retaining Walls
  • Sewer Realignment/Pump Station Relocation
  • Liaison with Agencies/Public/Adjoining Property Owners

State Highway 3 in the St. Joe River Valley