The Buena Vista County Board of Supervisors on Wednesday approved a pre‑construction agreement with the Iowa Department of Transportation for Phase 3—the final phase of the Platinum Crush road project east of Alta.
Phase 3 focuses on redesigning Iowa Highway 7’s intersections with 70th and 80th Avenues, the last major pieces of roadway tied to the crush plant’s transportation network.
County Engineer Bret Wilkinson told supervisors the agreement outlines how responsibilities will be divided as the DOT takes over design and construction of the state‑controlled portions of the work. He said the DOT will design, let, and inspect the construction of the project.
Wilkinson said the agreement also clarifies what the county will continue to own and maintain once construction is complete.
The agreement does not include any dollar amounts. Instead, it confirms that the county will provide the DOT use of its existing right‑of‑way at no cost and sets the framework for additional agreements still to come.
He said County Attorney Paul Allen reviewed the language and found no issues.
The DOT also included its most current—but still preliminary—design sheets with the agreement. Those plans show proposed realignments at both intersections and several culvert replacements, including a new entrance culvert near Saint Andrews Drive. Wilkinson emphasized those plans are not final and will continue to evolve as the DOT refines the design.
Wilkinson noted that additional agreements will address funding, construction sequencing, and other details as the project moves forward. The agreement will now be returned to the DOT’s District 3 office for final signatures.
