With the study of the environmental impacts now complete, actual design of the Timmerman to Ketchum improvement project of Idaho 75 will commence immediately, the Idaho Transportation (ITD) announced Sept. 4.
The project will be broken into separate phases for planning and construction, with phase one to begin as soon as a consultant can be hired. Initial design and establishing the final grade and placement of the reconstructed road will be the first steps of the development process.
None of this could happen until the Record of Decision (ROD) was signed by the Federal Highways Administration (FHWA), which was received by ITD in August. The ROD is the final step of the Environmental Impact Statement.
“The ROD had to be completed before we could begin any of the survey or design work,” District 4 Engineer Devin Rigby said. “Identifying all possible impacts is paramount to a successful construction project. Designing and building the road takes all the environmental findings into account.”
Included in the first phase is development of preliminary engineering and right-of-way plans, acquisition of right of way and initiation of preliminary construction, as defined in the Environmental Impact Statement (EIS). The three priority projects in the first phase all between Hailey and Ketchum are expected to be developed concurrently over the next year and a half.
As much as $27 million will be used to fund the first phase. Any excess from phase one will be available for later construction. Subsequent phases of planning and construction will happen over many years, contingent upon expected federal funding.
“These initial projects lay the groundwork for any funding that might become available in the next few years,” Rigby said. “We need to address the critical needs before additional development in the area makes planning and construction more complicated.”
A parallel project to all construction will be mitigation for wetlands and environmental impacts within the corridor, which fulfills a requirement of the EIS. The Boulder Flats mitigation site near Phantom Hill will be designed and constructed at the same time as the projects in the corridor. Mitigation will include restoration of wetlands along Idaho 75.
The total cost for all phases of the 26-mile corridor, estimated in 2008 dollars, is $250 million. Construction, beginning with phase two, is scheduled to begin in 2012.