By Jennifer Kotila
COKATO, MN Smith Lake, a 330-acre shallow basin located north of Highway 12 on Wright County Road 5, is in the process of a drawdown in order to improve wildlife habitat.
Smith Lake was labeled a “designated wildlife lake” by the Department of Natural Resources (DNR) in 2009, one of over 40 Minnesota lakes to have received that designation.
The designation allows the DNR to temporarily lower lake levels periodically to improve wildlife habitat. It also allows the DNR to regulate motorized watercraft and recreational vehicles on the lake.
Without the designation, the DNR needs formal permission from all the shoreland owners to lower lake levels.
In order for Smith Lake to be designated as a wildlife management lake, public hearings took place in the fall of 2008, after Ducks Unlimited (DU) engineered a plan for the drawdown of the lake.
The project on Smith Lake was made possible by a strong partnership between DU, the DNR, local stakeholders, and the Lessard-Sams Outdoor Heritage Council, according to a news release from DU.
Why a drawdown is needed
“I remember the lake in its prime after the drought of the ’30’s. I have never seen as much wildlife on the lake as there were in those days,” said Dan Nyquist, who owns land on the lake shore.
Due to an abundance of invasive fish, Smith Lake has been in a very turbid, degraded state for years and no longer supports migrating and brood-rearing waterfowl, according to the news release.
“The lake became like the dead sea with all the rough fish in it,” Nyquist said. “I have been wanting to see something like this done for 40 years.”
Six years ago, a fish barrier, called a velocity culvert, was placed downstream in order to prevent invasive fish, such as carp and bullheads, from entering into the lake, according to Fred Bengston, DNR wildlife supervisor.
A velocity culvert is a culvert that is placed at a certain grade which fish cannot swim up.
While the fish barrier has worked well to keep new fish from entering Smith Lake, Bengston said there has not been a significant enough winter-kill to rid the lake of the invasive fish that were already there.
“The whole lake is full of carp. When it rains, the carp fill up the creek on my property you could walk across them they are so thick,” Dennis Larson, who also owns land on the lake shore, said.
The last time there was a significant winter fish kill was in the winter of 2001, before the fish barrier was installed. The following summer, Smith Lake was a clear, beautiful lake, according to Bengston.
A drawdown of Smith Lake will also help to promote the germination and growth of aquatic plants and invertebrates favored by ducks and other wildlife, according to the news release.
The return of aquatic plants and invertebrates, along with the removal of invasive fish, will improve the quality of the lake water, which benefits downstream water resources, as well.
Work began mid-November to clear the outlet channel and install nearly 1,000 feet of 24-inch pipe.
Larson gave the DNR a 50-foot easement to do the drainage through creek bed that runs through his property.
Although work started a month later than planned, Landwehr Construction, the company hired to install the infrastructure for the project, was able to finish what needed to be done before winter set in, according to Bengston.
The company will resume work next spring, placing additional pipe further into the lake to draw out more water, Bengston said.
Thus far, the lake has been drawn down eight inches and is being monitored weekly, Bengston said.
With Smith Lake being a larger lake, part of an agricultural watershed with numerous drain tiles, and with the fact there has been an unusual amount of snow this year, Bengston anticipates the drawdown to take place over a two-year time period.
If there is a dry spring and summer, Smith Lake may be improved for wildlife in one year.
After there is a mud flat on the majority of the lake, a “jungle” of plants should start to grow, according to Bengston.
The DNR seeded the lake with wild rice this year, which provides brood cover for breeding waterfowl and is an important food source for migrating waterfowl.
The wild rice seed was collected from the Brainerd area, and there are questions as to whether or not it will take hold since Smith Lake is a little south of the transition area for it, according to Bengston.
There is no need to seed the lake with other plants, as there is hundreds of years of seed stored on the bed of the lake, Bengston said.
After the aquatic vegetation begins to grow, the lake is allowed to fill back up by placing stop logs in the outlet, Bengston said.
“It will be interesting to see what happens, how long it takes for the lake to fill with water again,” Larson said.
Smith Lake will be about a half-foot below the natural run-out of today because the run-out has filled in over the years.
Every 10 to 15 years, Smith Lake will be drawn down again to help maintain its wildlife habitat.