Unusual winter weather has brought unusual sights on lakes formed by dams on the Tittabawasssee River -- exposed sand and gravel bars, stumps, stones, docks standing high above lake surfaces.

But it's not that lake levels are lower than normal, says an official of the company that operates the dams.

It's that the exposed lake bottoms are, well, exposed.

"Every year, beginning about Dec. 15, we pull the lakes down about three feet, all four lakes," said Frank Christie, general manager of Boyce Hydro, of the Tittabawassee River impoundments behind dams at Sanford, Edenville, Secord and Smallwood.

"That's about how far (down) they are now," he said in a phone interview this week.

"I've heard people complain that the lakes are too low, but the difference, I think, is that there's no ice.

"This is the first time in 50 years that there's been no ice on the lakes when we draw them down, and everyone can see just how far three feet is. I think that's what's happened."

In normal years, a blanket of ice and snow would remain when the water was withdrawn from beneath it. The ice and snow would either lie on the otherwise exposed lake bottom or remain suspended above it.

Neither is as visibly dramatic as exposed mud, stumps, clamshells and sand.

The drawdowns are done, Christie said, so that the lakes are ready "to catch a little of the spring floods so they don't have as much impact downstream, particularly at Midland.

"They also allow us to do some work on the dams, and allow people to work on their (lakefront) property, working on things like seawalls."

Some have assumed this year's more dramatic-looking drawdown was connected to upcoming work on the Wixom Lake dam at Edenville, but Christie said that's not the case.

He said that drawdown and work "is tentatively scheduled for summer 2013."

Come summer or autumn, he said, "we'll start a public notice campaign, (explaining) our plan to draw down, how much and for how long, all that. None of that is finalized at this point," he said, adding that the company is working with the Federal Energy Regulatory Commission on those plans.

FERC, which has oversight of hydroelectric dams, has not required but has "strongly encouraged" the company to do the work, Christie said.

A Wixom Lake Association newsletter last spring said Wixom Lake drawdowns of about eight feet are expected for three summer months each in 2014 and 2018.