Group that oversees Clean Water Fund talks Canada goose control

Dec. 18—WORTHINGTON — A healthy Canada goose population on and around Worthington's Lake Okabena can be heard and seen this time of year as they congregate on any last remaining areas of open water.

While some may enjoy the beauty of the local wildlife, others do not appreciate what the flocks leave behind — either in the lake or on the beaches and in the parks.

During the annual meeting of the Clean Water Partnership last Thursday, Okabena-Ocheda Watershed District Administrator Dan Livdahl said the Minnesota Department of Natural Resources estimated 5,000 geese on Lake Okabena two weeks ago. Those 5,000 geese contribute an estimated 3 pounds of phosphorus to the lake per day through the feces they leave behind.

"There's so much goose (poop) on Centennial Beach that that beach would be closed all year because of e.coli bacteria," Livdahl told CWP board members, who include two representatives of the Worthington City Council, two representatives of the Okabena-Ocheda Watershed District and one community resident.

Livdahl raised the goose issue during a lengthy discussion about the lake's toxic algae blooms, which stretched from mid-July into September this year. The city erected signs at boat landings and beaches recommending the public and their pets refrain from recreating in the water when toxic blooms were present.

City Councilman Chad Cummings said some sort of goose deterrent is being discussed by the city. He specifically noted one option to use strobe lights on public docks and floaters in the lake that would keep geese away, but not be distracting to people.

"We get told all the time at Centennial (Beach), 'What do you even put those docks out for?'" Cummings said, noting that the docks can be cleaned one day and completely covered in goose droppings by the next. And when they aren't on the docks, the geese are on the beach.

He said they want to keep the docks in place so people recreating on the lake can pull up to a dock and use the restrooms or visit the Beach Nook, but noted that attaching strobe lights to the docks — or having them float in the lake — will create other issues for boaters.

Livdahl said he'd like to have people with herding dogs go out to the areas where the geese commonly congregate starting in March and April and continuing through the end of the nesting period to keep the geese away. This would encourage them to nest elsewhere, away from Lake Okabena, and hopefully stay away from the lakeshore.

"It's more than just the feces," Cummings added, noting that people walking or biking around the lake have encountered geese hissing at them. There is a concern the birds could chase after or bite people if they feel threatened.

OOWD Manager Jay Milbrandt asked if the lake's aeration system encourages geese to stay through the winter.

"Is it a way to keep the phosphorus out?" Milbrandt asked in his recommendation to leave the aeration system off this winter.

"If oxygen levels get too low, are people going to care if there are geese floating on the lake in February when you get thousands of dead fish?" responded Cummings.

Livdahl said oxygen levels on Lake Okabena were really high last winter, when most other shallow lakes in the area experienced significant winter fish kills due to snow cover on lakes leading to low oxygen levels.

"DNR people said they don't think aerators work," Livdahl added. "But if they tell you to turn them off and there's a fish kill, they don't want to be to blame."

"We'd like to see the aerators not turned on unless it's needed, and do more dissolved oxygen testing to make sure it's needed," he said.

While there was no official vote taken, there was a consensus to ask city staff to not turn the aerators on unless testing showed oxygen levels were getting too low.

In other business, the partnership:

* Authorized funding for test strips for the watershed district to monitor for the presence of microcystin and cylindrospermopsin toxins in Lake Okabena. Livdahl said the total cost for test strips this year was $1,689, and noted that the city's Clean Water Fund was accessed to pay for the strips, while the watershed's contribution is to do the testing. Livdahl also noted that the city's Clean Water Fund currently had a balance of more than $54,300.

* Agreed to reimburse the watershed district for half the cost of tree mowing at the Prairie View property. This year, the district hired Henning Construction to do the mowing at a cost of $300 per hour for nine hours. The city's parks department went out a couple of weeks later and finished the job.

Livdahl said mowing down the volunteer trees will likely need to be done every year on the property.

* Learned about the need to set aside funds to remove sediment from the sand filters at Prairie View, and to replace the sand in the filter within the next year.

"We need to remove the crust on the surface — the sediment and the sand together — and then replace the sand every three to four years," Livdahl reported. "Next year I think we need to replace the sand."

He said the last time the sand had to be replaced — due to a construction error — it cost $25,000.

"The watershed district will probably direct that activity, but having some money to help cover maintenance out there would be a good thing," Livdahl said. "This board has typically paid half."

* Discussed continued carp control efforts on Lake Okabena. Livdahl reported that southwest Minnesota's commercial fisherman was unable to conduct a seining operation on the lake prior to it freezing over this fall.

"We know the carp population is not super high in the lake, but we don't want it to get to 100 kilograms per hectare either," Livdahl said, raising the idea again of herding carp into Sunset Bay during spawning season and then netting them out. Carp Solutions is a Minnesota-based company who has box nets available to complete the work.

"If we're going to do something with carp, we need to get on Carp Solutions' list to do something in April or May," Livdahl said. "They're the experts and I think they're interested in coming down here and working with us."