There is an old saying about what authority figures really mean when they dispense advice: "Do as I say, not as I do."

Department of Natural Resources fisheries officials do not want be accused of being that way. So among the projects on the division's short list of missions to accomplish is removal of two dams at Thompson State Fish Hatchery in the Upper Peninsula.

Fisheries officials have been trying to remove outdated or unnecessary dams from Michigan waterways for several decades now. There are a wide variety of issues associated with dams, ranging from the simple and obvious -- they block the upstream migrations of fish -- to their potential for ecological disaster (such as the recent unintentional release of water and sediment that killed thousands of fish and damaged habitat on the Pigeon River).

"A lot of our small communities were built on rivers with nearby dams to harness water power," said Chris Freiburger, a fisheries biologist who works on dam-licensing and habitat issues out of the DNR's Lansing headquarters. "They put in mills, for instance, or they were used to generate power.

"Typically, the life expectancy of a dam is 50 years," Freiburger continued. "Most in Michigan are older. Something has to happen soon."

Not only are many of those dams aged -- and in need of repair or replacement -- many of them also no long fulfill their original roles.

"They're not generating power any more, very few are actually flood-control dams, and nobody wants to pay to have them fixed," Freiburger said. "It makes sense to remove some of these things as soon as we can.

"Five or six years ago, there were a couple of these coming out every year. Now there are five to 10 coming out every year."

The DNR is optimistic that in 2009, two of them that are owned by the agency will come out from the Thompson fish production facility. They fit the main criteria: they no longer serve a purpose -- and one of them, on Williams Creek, is no longer operating.

The old concrete and earthen dam built on Williams Creek in 1924 has been open since 2003. The remaining dam on Thompson Creek, located downstream from the hatchery building, impounds less than an acre of water and is no longer necessary.

Jessica Mistak, a habitat biologist at Marquette, said removing the dams will pay several dividends.

"There are costs associated with owning dams," Mistak said. "They have to be inspected by the Department of Environmental Quality regularly and often require maintenance."

But more importantly, removing the dams will provide habitat for migrating fish as well as some angling opportunity.

"Removing the upper dam would open up about two miles of stream," Mistak said. "It's a relatively short distance to the headwater, but there's still a resources benefit. There is a run of salmon and steelhead from Lake Michigan and it's pretty popular with anglers. Some of the local fishing groups have even done habitat improvement work downstream of the dam."

But it's not a simply a matter of removing the dams; the DNR, like anyone else, must obtain permits from the DEQ for dam removal. Although the Williams Creek dam is no longer functioning, there is enough of the old structure in place that a removal permit is required.

"We're hoping to use our heavy equipment crew to do the work for cost savings," Mistak said. "We hope to get the permit paperwork in this fall."

The Thompson Creek Dam, however, is another matter. This dam was built in 1944.

"We'll want to draw it down slowly to allow upstream sediment to stabilize," Mistak explained. "Managing upstream sediment typically is a large cost of removing a dam. First, although we have no reason to believe there's a problem, we'll have to follow procedures and make sure the sediment is not contaminated.

"Second, we have to determine how much sediment is in there and how to prevent it from becoming mobilized," she continued. "If there's enough that will move when the take out the dam, we could have a fish kill and we could kill aquatic insects and cover up spawning habitat."

If there is a lot of sediment Mistak said the DNR may have to construct some sort of sediment traps to collect sediment before it washed downstream. But she's optimistic that won't be too difficult a task.

"We expect this to be a rather seamless process," she said. "We've built a collaborative process with DEQ that gets them involved early. In fact, we work with the DEQ before we even apply for the permit and begin collecting information on the existing habitat."

Not only will removing the two dam structures associated with the Thompson Hatchery cut DNR costs and open up more habitat, it also should serve as an educational tool for DNR staffers who will be working on dam-removal projects in the future, too.

"We're gaining knowledge as we go along," Mistak said. "We expect this to become more common in the future and, as we begin removing more of our own dams, we'll have staff on hand to know how to do this safely and in a cost-effective manner."