SANDPOINT — Road damages from extensive stormwater runoff are expected to surge past the $1 million mark.

A section of Cocolalla Loop Road failed late Sunday night or early Monday morning after a culvert became overwhelmed by stormwater.

“The culvert wasn’t large enough to handle that volume of water,” said Bonner County Emergency Management Director Bob Howard.

Stormwater scoured the west side of the road, ultimately undermining the base of the road and causing it to fail. Landowners along the road can still get to and from their homes because each end of the loop road remain open.

Other residents aren’t so lucky.

Parts of Bowen Arrow Road in Samuels are impassible, which means residents have to traverse the muddy track on foot.

Bonner County Commission Chairman Cornel Rasor verbally declared a state of emergency on Saturday, a declaration which is expected to be put in writing today.

The declaration allows the county to apply for state or federal disaster relief funding to repair public roads maintained by the county, such as Cocolalla Loop.

Repairing the loop road could cost an estimated $500,000-$600,000, according to Howard.

Bowen Arrow Road residents, meanwhile, are on their own. Though public, the road is not maintained by the county because developers did not build the route to a standard which allows it to be included in the county’s maintenance program.

“There’s no funding or assistance available for those roads,” said Howard.

Howard said a contingency plan has been developed to use military-grade vehicles to get responders through the closed section of road if they are summoned to a medical emergency.

Landowners along public but privately maintained roads have to foot the bill to bring the road to a county standard before it can be considered for inclusion into the county maintenance program.

Part of Merril Martin Road in Sagle has failed, although there is nobody living above the closure, Howard said.

Part of Grouse Creek Road has also failed, but motorists can use other roads to detour around the closure.

Last week’s storm event has caused an estimated $800,000 in road damages. A prior storm event had already done about $200,000 in damage, according to Howard.

“It’s getting quite expensive,” he said.