Sub-zero temps help ice thickness, but caution still urged

Tuesday, January 29, 2019
Ice ridges often create seams of open water or thin ice like the location seen here near Upper Gar.
Photo by Dave Stanley

Local officials responded to a pair of emergency calls over the weekend after recreational vehicles fell through the ice, according to Mark Petersen, a dive captain with Arnolds Park/Okoboji Fire & Rescue. The Dickinson County Communications Center received its first call for assistance at 8:37 p.m. Friday.

"We were called out for a report of a four-wheeler with two people who broke through the ice close to Okoboji Island (directly north of Trigg's Resort)," Petersen said. "When we got there, we actually found out it was two four-wheelers with four people. One person had made it west to safe ice and the other three were able to head east and made their way over to the Waterfront restaurant."

All of the ATV passengers were evaluated by medical personnel and escaped serious injury.

"We deployed pretty quickly, and everybody was already out of the water and on safe ice by the time we got out there," Petersen said.

Arnolds Park/Okoboji Dive Team members were called out again at 10:32 p.m. Saturday after a snowmobile fell through the ice.

"When we got there, we found two people who actually had to break though quite a bit of ice until they found enough ice to get crawled up onto," Petersen said. "We were able to approach them with the airboat and get them securely inside the airboat. We took them to shore over at Triggs' boat ramp. In both instances, that airboat was the key to getting us out there safely and back."

The Iowa Great Lakes area saw added traffic due to the 39th Annual University of Okoboji Winter Games celebration. Administrators with the Iowa Great Lakes Area Chamber of Commerce remained in contact with the Iowa Department of Natural Resources regarding events held on ice.

"The main thing is, we never, ever encourage people to drive onto the Lakes," IGLA Chamber CEO Blain Andera said.

The Iowa Department of Natural Resource officials had a "foot traffic only" recommendation for Winter Games participants.

"Generally, we're seeing 12 to 14 inches of ice, but it's the weak spots that have everybody worried," the DNR's Mike Hawkins said, before the weekend. "There are places where we've had open water — and for whatever reason, we've had a lot of it this year in some places where we haven't seen it before."

Petersen said the mid-week, sub-zero temperatures will certainly add ice thickness.

"But that doesn't mean there can't be holes that are still weak," he cautioned. "We haven't had a big, open patch of water that late in the season over on East Lake, like we did in front of Bridges Bay and that whole complex. But, boy, this year we sure did. Conditions are always changing. That's what I always tell people, 'when we do things on the lake, we don't go anywhere without checking the conditions ourselves.'"

Hawkins noted trouble spots around the bridges and at any constricted or narrow spots on the lake.

"Those spots are always a place to be concerned about — especially this year, because there's quite a bit of water moving in the system, and that moving water creates unsafe ice conditions or no ice at all," he said.

Even lake travelers who know the traditional locations for weak ice should use extra caution this year. Hawkins encourages visitors to watch for ice ridges — or pressure ridges — on the Iowa Great Lakes. The ridges are formed by sheets of ice pushing against each other. Sometimes, the buckled ice is highly visible and easy to avoid, but other ridges settle back down through contraction and expansion.

"They typically run in the same areas but this year, we're seeing some pressure ridges in some non-traditional locations," Hawkins said. "So, even people who are familiar with how the ice works on, say, West Okoboji are caught a little bit off guard this year."

The DNR season-long recommendations include a minimum of four inches of clear ice for fishing and at least five inches for snowmobiles and ATVs. 

"We've all been waiting for cold weather to get here, let's just give it some time to make ice," Joe Larscheid, chief of Fisheries for the Iowa Department of Natural Resources, said.

Just because arctic weather is here, anglers shouldn’t abandon their ice safety practices, he added.

"The cold weather definitely helps to grow ice, but when ice is covered by a blanket of snow, the snow acts like insulation, slowing ice growth," Larscheid said. "Anglers should treat all ice like new ice and check its thickness frequently when heading out."

The Arnolds Park/Okoboji Dive Team has had its airboat for almost a decade, and Peterson estimates the vessel has helped responders reach about 25 people who have been in thin ice situations.

"We've probably helped another 25 people who have had an accident or injury out on the lake," he said. "The response on an airboat is quick because we don't have to check ice conditions on our way out to where somebody's at. We can deploy the boat and respond immediately. … It was 100 percent donation funded in a short amount of time, so us (as a department) and the many people who have been helped would like to say 'thanks.'"

The DNR's ice safety tips on include:

• No ice is 100 percent safe.

• New ice is usually stronger than old ice. 

• Don’t go out alone — if the worst should happen, someone will be there to call for help or to help rescue.

• Let someone know where you are going and when you will return.

• Check ice thickness frequently — there could be pockets of thin ice or places where ice recently formed.

• Avoid off-colored snow or ice. It is usually a sign of weakness.

• The insulating effect of snow slows down the freezing process.

• Bring along these basic items: hand warmers, ice cleats to help prevent falls, ice picks (wear around your neck) to help escape from the water, a life jacket, a floating safety rope, a whistle to call for help, a basic first aid kit and extra dry clothes, including a pair of gloves.

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