DNR, OOWD strategize over Lake Ocheda
WORTHINGTON — With the lack of a significant fish kill on Lake Ocheda this past winter, the Okabena-Ocheda Watershed District (OOWD) board met with several Minnesota Department of Natural Resources officials and a Ducks Unlimited biologist Tuesday afternoon to discuss options to bring the nearly 1,700-acre lake back to a healthy state.
At issue is the extremely large population of rough fish that continually stirs up bottom sediment, preventing sunlight from penetrating the murky waters of the lake’s three basins. Without sunlight, submergent vegetation can’t grow in the shallow prairie lake.
For the past two winters, the watershed board has hoped low water levels would result in a significant fish kill . The hope was greatest this past winter, when ice thickness extended all the way to the lake bottom in places.
With the spring thaw came the discovery of dead bullheads, carp and even walleye along the shoreline, but it was soon realized a healthy population of fish survived. It has now led the watershed board to begin considering options for a management plan that would focus primarily on improving water quality. The lake’s status as a fishery would be of secondary importance.
Watershed board members Les Johnson and Rolf Mahlberg said the district has long talked about the turbid state of Lake Ocheda. The decision now is whether the watershed district will take the lead on developing a management plan for the lake, or let the Department of Natural Resources and Ducks Unlimited step in to begin the project.
Josh Kavanagh, a biologist with Ducks Unlimited, said Tuesday that DU has partnered many times with the DNR on projects in the prairie pothole region of Minnesota.
“Really, the key in improving these shallow lake systems is aquatic plants,” Kavanagh said. “One of the best tools we have is doing the water level drawdown.”
Since DU began partnering with the DNR in 2004, Kavanagh said the organization has been successful in improving lakes, doing up to 10 projects per year.
“Our primary interest is habitat — waterfowl habitat,” he said.
“There’s no reason a body of water this size can’t be good for ducks and fish,” Johnson responded. “What’s good for ducks is good for fish. This isn’t about making it a duck lake. It’s about making it a clean, environmentally friendly lake … that attracts both waterfowl and fish.
“Healthy lakes have aquatic vegetation; unhealthy lakes don’t,” he added.
Lake Ocheda isn’t the only shallow prairie lake to suffer from poor water quality. DNR Area Wildlife Manager Bill Schuna said his agency worked with Ducks Unlimited on Curtis Lake near Cottonwood. In 2006, the lake was full of rough fish and algae. After back-to-back winter kills through a drawdown, water clarity has improved immensely.
Schuna said it would be impossible to de-water Lake Ocheda’s basins completely, but the lake level could be brought down low enough to ensure a winter fish kill.
A drawdown plan may generate concerns among some residents whose shallow wells could be impacted by a drawdown, cautioned OOWD Administrator Dan Livdahl.
While DNR officials could offer no guarantee that wouldn’t happen, groundwater specialist Jim Sehl said the matter would have to be researched.
The bigger issue at this point is the impact it would have on Worthington’s wells, as water from Lake Ocheda flows to Lake Bella. However, with the ongoing drought, there is little water flow entering the wellhead.
“We don’t have to simulate a drought — we’re there now,” said Worthington Public Utilities General Manager Scott Hain. “From a water supply and management (standpoint), everyone looks at Lake Bella as being a critical body of water for our well supply recharge. However, I think it’s foolhardy to say the water in Lake Ocheda doesn’t impact that as well.”
Hain said drawing Lake Ocheda down by two feet is the equivalent of more water than the city of Worthington uses in a year.
“It would add 19 feet to Lake Bella,” Hain said. With no way to keep that water in place, it would flow into Iowa and be lost.
Hain expressed appreciation that the drawdown didn’t occur two years ago, prior to the city’s water concerns. If a drawdown is done now, it would take 46 million gallons of water to raise the water level by one inch across Lake Ocheda’s three basins.
“We’re potentially looking at an awful long period of time before we see any water moving down to Lake Bella,” Hain said.
Already, WPU is getting about as much water as it can from its two hook-ups with Lincoln-Pipestone Rural Water, and the Lewis & Clark Regional Water System project is still in limbo. At the most, the water project would offer two-thirds of the city’s daily water needs when it does arrive.
“You get good news in two weeks (about Lewis & Clark), and you could do this (drawdown) in three years,” Hain said.
Still, Hain said he didn’t see a reason why the watershed district couldn’t proceed with developing a management plan and having it in place until a drawdown can be conducted.
If the watershed district chooses to be the lead agency for a drawdown, it would need to have at least 75 percent landowner approval to move the project forward. On the other hand, if the DNR proceeds, it wants to know there is public support, but that it’s not tied to a percentage of the landowners.
“I think we’re real close to that 75 percent, and with some more education, I think we could get to 80 (percent),” said Paul Langseth, an OOWD Advisory Board member.
“I think this board is unanimous that we want to enhance the quality of that body of water,” Mahlberg added. “It starts with us and the commitment we have. The board is universally supportive of making that lake function.”
Livdahl said the watershed board will host a public informational meeting this summer to educate landowners. At the same time, the DNR and Ducks Unlimited will work on feasibility issues for a drawdown.
Daily Globe Reporter Julie Buntjer may be reached at 376-7330.