Lake algae a concern
Lake Okabena Improvement Association wants to speed up process to improve lake's health
WORTHINGTON -- Consultants hired by the Lake Okabena Improvement Association (LOIA) may be able to quicken the process of improving the health of the local lake.
John Downing, a limnologist at Iowa State University in Ames, and Rich Brasch, a senior scientist at Wenck Associates Inc. of Woodbury, met with LOIA board members, city, Nobles County and watershed district personnel for more than two hours Wednesday afternoon. The group discussed water quality and water clarity in Lake Okabena, and steps to increase both.
The two were asked to develop possible solutions to the algae blooms that smell bad, look worse and essentially put a halt to summer-time recreational activities on the lake.
"As a lake association ... we wanted to look at a larger scope of the lake and what we could do for water quality," said Genny Turner, president of LOIA. "Water quality is the biggest concern we have as a lake association."
With Lake Okabena slated to be added to Minnesota's list of impaired waters this year, the lake association wants to start work on projects to benefit the lake and move up the estimated 2012 timeline for conducting a TMDL (Total Maximum Daily Load) study. A completed study is required before state funds can be accessed to make improvements.
Brasch said in the months since his firm first met with LOIA, it has looked at the data collected on Lake Okabena and the work completed by the Okabena-Ocheda Watershed District. With input from attendees on Wednesday, he said Wencl will complete a report and provide recommendations for the community to take the next step.
Downing spent much of the meeting talking about the condition of the lake as well as projects he has worked on, including the cleanup of Clear Lake in north central Iowa. He called Lake Okabena hypereutrophic, meaning it is more productive than it needs to be. As more nutrients collect in the lake, the worse it gets.
"We've got 14 acres feeding into each acre of the lake," said Downing. "The more acres you have coming in, the more nutrients you have coming into the lake."
While nutrient levels -- mainly phosphorus -- feeds into the frequency and severity of algae blooms, Downing said there isn't enough data on the sources of those nutrients to adequately prescribe a "surgical" fix for the lake.
Two recommendations he did make were to conduct dredging in Sunset Bay to reestablish a water detention structure, and to divert flow from Whiskey Ditch to somewhere other than Lake Okabena.
The diversion of Whiskey Ditch poses a series of questions, however, such as the impact it would have on the lake level.
"You probably don't need the water, and you sure don't need the nutrients," said Downing, adding that up to 50 percent of the sediment coming into the lake flows in through Whiskey Ditch.
City Engineer Duane Haffield was concerned with the suggestion, saying Whiskey Ditch is used for flood management and diverting it away from Lake Okabena would require storage elsewhere.
Setting a goal
Downing encouraged the nearly 20 people in attendance to develop a "broad community agreement" on restoration goals for Lake Okabena. He suggested they update the land use GIS data and compile a hydrology report to identify how much water comes into the lake from other sources.
The main goal is to reduce phosphorus concentration in the lake. Downing said average phosphorous levels from the late 1980s to today is 206 parts per billion (ppb). Haffield said more recent data put the average at 120 ppb, while the Minnesota Pollution Control Agency (MPCA) wants the level closer to 90 ppb.
"Ninety (ppb), I think, is very attainable for Okabena," said Downing. "I think you can do considerably better than that."
Brasch said there is no harm in asking the MPCA if work can begin early.
"Let them know that we think we can and we want to do better," said Brasch. "How well you are positioned to get funding is a little up in the air."
While the LOIA wants to move forward as soon as possible, it is not a taxing authority and therefore cannot apply for funding from the MPCA. It will take a governmental body -- such as the city, county or watershed district -- to request those funds.
Brasch recommended submitting a letter to the MPCA to request TMDL preparation dollars.
While the dollars would be awarded to the taxing authority, Brasch said the money could then be used to hire the consultants to begin the work.
"The state is enthused if a third party is willing to step up and do the TMDL, rather than the MPCA having to do it," Brasch said. He added that if the TMDL was advanced, the project could get funded as early as July 2011.
"If you've got local leadership ... somebody to step forward, it looks like you have the prospects (to get funding earlier)," said Brasch. "You could make some significant strides."
Worthington City Administrator Craig Clark questioned the need to have consultants do the work, saying it would displace some of the work the MPCA would do.
There was some discussion Wednesday on which governmental body would request funding for the TMDL.
Okabena-Ocheda Watershed District Administrator Dan Livdahl said all three lakes in the watershed -- Okabena, Ocheda and Bella -- are slated to join the list of impaired waters this year.
"To me, it makes more sense to have the watershed take the lead," said Livdahl.
LOIA member Craig Bergh questioned if the city was interested in supporting water quality outside of the city limits.
"I've got to confess that I don't really care about what happens outside of the city," Bergh said.
Livdahl replied that the city's water supply is fed via wells at Lake Bella.
Other questions raised at Wednesday's meeting were the potential of reducing rough fish in Lake Okabena and the use of copper sulfate to reduce algae blooms.
Downing said phosphorus levels in the lake likely would not be impacted by removing more rough fish; and the use of copper sulfate is not recommended because it won't solve the problems long-term.
Alderman Lyle Ten Haken said he would take the information from the meeting to the Worthington City Council for further discussion.
"Everyone in this room has a concern about water quality. Those that are heavily involved in it are putting it at the top of the list," Ten Haken said. "While we all have a high commitment to the lake, we can't just drop everything and say, 'Here we go.'"
Ten Haken said he didn't want people to get disenchanted with the speed in which the city works on issues pertaining to the lake.
"We just don't leave this meeting and go over there and get things rolling," he said. "We want to charge ahead ... just don't browbeat us."
Clark interjected, "We want to do this right so we get the best product possible."