Post date: Feb 02, 2010 7:16:23 PM

Johnson Lake shore no match for ice

Photo by: CNPPID Heaving ice has pushed ashore in

some neighborhoods on the east side of Johnson Lake.

The force of the ice has resulted in piles of riprap, bulges

in soil and buckling sidewalks in some yards.

By LORI POTTER Hub Staff Writer -- Tuesday, Feb. 2, 2010 Kearney Hub on line at: http://www.kearneyhub.com

HOLDREGE — The east shoreline at Johnson Lake is proving no match against heaving ice that’s pushing ashore, causing rip rap to pile up, soil to mound and sidewalks to buckle in some yards.

“It’s the place where the ice found the least resistance,” Central Nebraska Public Power and Irrigation District Natural Resources Manager Mike Drain told the Central board Monday.

He explained that there’s less dirt on the east shoreline to push back against the ice, so that’s where the heaving problems are most apparent.

Drain said cracks that form in the frozen lake may fill with water that freezes, and then the ice pack expands outward. CNPPID Real Estate Administrator Frank Vetter described the conditions as “kind of a glacier effect.”

Vetter showed the board photos he took in back yards in the East Shore, Northeast Bay and Crappie Corner neighborhoods. He said that as the ice expands, it pushes on the shore and lifts the soil and riprap.

Among the concerns are possible damage to underground electrical and lawn sprinkler systems. One photo showed a buckled concrete walkway next to a backyard patio.

Vetter said a Johnson Lake resident told him she’s checking with her insurance company to determine if her policy will cover ice-related repairs.

Unrelated circumstances have other CNPPID officials monitoring a possible seepage issue below the Johnson Lake dam.

Gothenburg Division Manager Kevin Boyd said he was contacted Friday by a Central patrolman who noticed water in an area where he hadn’t seen it before. When the patrolman chopped through the ice, he noticed moving water.

Further investigation showed that water was present in the mornings over the weekend, but had stopped by afternoon.

Boyd said it hasn’t yet been determined if the water is a result of snow melting off the dam or if there is a seepage issue. However, Central’s license conditions required him to call Federal Energy Regulatory Commission officials in Chicago to report the circumstances.

“It’s just a very, very slow trickle at this point,” he said Monday. “... I just think we need to monitor it.” Boyd added that it may not be possible to determine where the water is coming from until all the snow is off the dam.

Photos are being taken daily as part of the monitoring. Also as a precaution, the lake was lowered. “It’s been lowered two feet, and I can’t say that we’ve seen any change,” Boyd said.

He added that tests on the dam, such as drilling core samples, won’t be done unless the water situation gets worse.

“We don’t even know that this is water coming through the dam,” Drain said, because the pattern still suggests that it may be delayed snowmelt trickling down the dam.