Carroll County to Begin Diamond Grinding on Hawthorne and Delta Avenues Next Week

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Carroll County supervisors have approved a $659,000 bid from Diamond Surface Inc. to begin diamond grinding work on Hawthorne Avenue between U.S. Highway 30 and Halbur, and a mile stretch of Delta Avenue north of Iowa Highway 141. The work could start as early as next week, though the exact start location is still to be determined. Motor traffic will still be able to travel during the project, but pilot cars are expected to cause delays.

Why it matters

The diamond grinding project is aimed at improving the road surfaces in Carroll County, which will benefit both local residents and those traveling through the area. The quick turnaround on the project is notable, as the county is using new communication methods to keep the public informed of the work.

The details

Diamond Surface Inc., a Minnesota-based company, was awarded the $659,000 contract to perform the diamond grinding work. The project will cover nearly 7 miles of roads, including Hawthorne Avenue between U.S. Highway 30 and Halbur, and a 1-mile stretch of Delta Avenue north of Iowa Highway 141. The contractors approached the county last week requesting contract approval so they could potentially start the work as soon as next Monday, March 23. While the exact start location is still to be determined, the plan is to completely finish one section before moving to the other.

• The supervisors approved the contract with Diamond Surface Inc. at their meeting on Monday, March 16, 2026.
• The pre-construction meeting is scheduled for later this week, after which the county will have a better idea of the exact start date and location.
• The diamond grinding work could begin as early as next Monday, March 23, 2026.

What they’re saying

What’s next

The county will have a better idea of the exact start date and location for the diamond grinding work after the pre-construction meeting later this week.