WATERLOO -- The long overdue reopening of the Winslow Road bridge will have to wait even longer.

Damage from an apparent arson early Friday could push back the opening date for the rural Black Hawk County bridge by two to three weeks, said County Engineer Cathy Nicholas. The bridge over the Cedar River between North Union and Taylor roads is being replaced and had been expected to open this week.

"We'll be asking the contractor to perform more tests," Nicholas said. "We're hoping the steel wasn't damaged by the heat of the fire."

A seeder loaded with 100 bales of straw was parked on the west end of the bridge as construction contractors worked to finish planting grass on areas around the structure. That seeder was destroyed when the straw was ignited and other equipment owned by the private contractor was damaged.

Nicholas said there was obvious damage to the bridge deck and guard rails, which will need to be repaired.

It was another setback for the $2 million project, which stretched on much longer than expected.

The 55-year-old bridge, which had carried about 1,000 vehicles per day, was restricted to one lane of traffic in 2004 after inspections found deterioration in the concrete bridge deck. The bridge was closed entirely in August 2006 when engineers from Shuck-Britson Inc. began worrying about "the deck falling out from under the vehicle."

Minnowa Construction Inc., of Harmony, Minn., was awarded the bridge replacement contract in January 2007. The early onset of winter last November and high river levels in the spring of 2008 hampered the project, and the contract is now overdue.

The county is expecting to collect liquidated damages from Minnowa for failing to finish the project on time, but no dollar amount has been negotiated to date.

"That's the frustration," said board chairman John Miller. "The contractor had a chance to get this done last year but put their resources to other projects."

Miller said he's hoping the latest fire damage can be repaired quickly and the bridge can open to vehicles.

"I'm hoping that it's open for school because that will impact the Janesville district," he said.

The Black Hawk County Sheriff's Office is investigating the fire in conjunction with the Janesville Fire Department and the Iowa State Fire Marshal. No damage estimate for the county-owned bridge was available.

Contact Tim Jamison at (319) 291-1577 or tim.jamison@wcfcourier.com.