Last week, I wrote Part 1 in my series on Lake Okabena. I asked whether Worthington is losing its greatest asset and whether the community is giving enough attention to the lake. The article received great feedback from readers. The response was unanimous and clear: The lake is one of our greatest assets and it needs more attention and investment from the community.
Given the response, I decided to expand the series into three posts to fully discuss solutions, particularly from feedback from readers.
Some Givens
First, lake quality is not a new problem. The challenges of a shallow prairie lake are not unique to Worthington. I’ve spent time on lakes all over the region and they all seem to get green in the summer (sometimes much worse than Okabena). It’s also not a modern problem—algae blooms were reported on the lake decades ago and lakes can go through cycles. Some challenges we have to live with, but we can learn from others.
Second, unfortunately, there’s no silver bullet. The long-term solutions are indeed long-term and could take decades to implement. In preparation for this series, I sat down with Dan Livdahl of the Okabena-Ocheda Watershed to learn about the many good things they are doing. We talked about everything from giant aerators to draining the lake and digging it out with mining equipment.
Defining the Problem
From the feedback I received, it’s clear that we are not proud of Lake Okabena, and a lot of that has to do with water quality.
Let’s face it, Lake Okabena is a shallow, mud bottom prairie lake—we will never have crystal clear waters. I’ve been in lakes and rivers and oceans around the world and, trust me, it actually gets a lot worse than our murky water. This is also getting better and, until the torrential rains this June, I noticed a lot of improvement. Praise goes to the Watershed team, which is working hard upstream, removing rough fish, and building retention ponds.
Algae—this issue may be the chief concern for citizens. The “green paint” algae blooms start as early as June now and inhibit us from using the lake, and even the parks surrounding the lake. The algae affects the most people. Boaters can’t use the lake, fisherman can’t use the lake, swimmers can’t use the lake. Have you walked around the lake during a bad bloom? The smell is horrific, rendering many of Worthington’s parks and bike trails unusable, not to mention being aesthetically displeasing.
Seeking Solutions
Can we address the cause? The cause of the algae is runoff. Approximately 70% of the runoff comes from Whiskey Ditch and 30% from town. Improving runoff is a long-term strategy that changes agricultural practices and land use for filtering. We definitely need to invest in the watershed, but there is overnight cure.
Can we address the symptom—the algae blooms themselves? Hopefully. One can largely kill the algae by chemically treating the lake on a monthly basis. This, however, has undesirable effects on fish and the ecosystem. As a nod to our local biotech companies, if you can create an economic, large-scale, ecologically harmless solution to lake algae, cities across the world will be clamoring for your product.
I am attracted to an out-of-the-box solution: Algae skimming.
Algae floats on top of the water, so it’s possible to simply skim it off the top like skimming the fat off broth. Several cities and lakes are now employing algae skimmers. An algae skimmer is much like a floating lawn mower: As you drive, rollers filter the water and deposit algae in a bucket. If seeing is believing, watch this video:
I spoke with the Minnesota-based manufacturer of the Eco Harvester above. The Eco Harvester will remove approximately 1 acre of surface algae per hour and it’s a good size for our lake. At less than $50,000, it costs about the price of a small tractor the city might use for maintenance (they offered under $40,000 for an end-of-summer sale).
I look at the algae problem much like having a giant park—we just need to mow it occasionally to make it useful. And, the algae can potentially be used as fertilizer after harvesting.
In my view, it’s worth having a conversation about whether an algae skimmer is a good investment for Worthington. An algae skimmer would solve our chief complaint and make the lake instantly more usable during the summer months. When other lakes in the region suffer algae blooms, Worthington would be a refuge.
Conclusion
There is much more to discuss about the future of Lake Okabena and how it fits into a strategic vision for Worthington. Clearly, we need to actively pursue solutions to immediately improve the lake. In my next post, Part III, we will discuss dredging. It may even warrant a new series on setting a vision for merging downtown and Sailboard Beach into a destination for shopping and dining. For now, I suggest that an algae skimmer may be part of that answer.
My question for you: Do you agree that an algae skimmer is part of the solution and would it be an investment supported by the community?
I like it.
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Looks awesome – it’s got my vote. I would think this could double as a Zamboni in the winter right? Can we put a pond hockey rink in over by my parents place Jay?
Ha, sure! You can drive it. Thanks, Zach.
Interesting comparison between mowing the grass at our parks and skimming the lake. I spent a few summers during college working for the City of Worthington mowing grass at our parks. First, I can say that (as of about 4 years ago) the local parks dept. owns and operates 4 industrial lawn-mowers, each of which cost about $40K. Assuming they had $0 of incremental revenue to throw at this issue, I would be willing to bet that the public would happily sacrifice 25% of the grass-mowing capacity in exchange for a cleaner, more useable lake. Second, if “Zach” is in fact who I think he is, then I second the vote for a pond hockey rink near his (my) parents’ place.
Thanks, Tim. Great inside scoop on the cost of industrial lawn mowers! Yes, you’ve identified the right Zach. I third the pond hockey rink.
Jay, I agree that the lake is probably the biggest asset to Worthington. It’ll be interesting the suggestions you have for changing farming practices. I would encourage you to investigate all angles before you suggest practice changes. I think you’ll be surprised that farmers are doing more to protect our water and land then most think. I look forward having you come out so we can walk through some of these practices.
Taking pride in our land and water, Farmer Chad
Chad, thanks for responding. I do not have any suggestions for changing farming practices. That question is involves the watershed and falls within the wheelhouse of the Okabena-Ocheda Watershed District. I’m focusing solely on what we can do at the level of the lake. I do know that the Watershed District has worked closely with farmer to address best practices for tiling and installing berms and filtering strips to minimize soil erosin. You can see more on the Watershed District website. Are there any practices that you think would help? Can’t wait to come out this fall!
I seen one of these being used on a TV show. Dirty Jobs maybe. When I seen it, I thought of it and our lake.
Interesting. Did it appear to be effective?
Given the amount of wind that we have here, I question how many days, hours, this unit can be used. From my observations, the algae slim only shows up on quiet, or nearly wildness days on the lee ward side of the lake. For instance, south shore has relatively few days where algae is a problem because of the prevailing southerly winds in the summer.
Thanks, John. You make a good point. The question, it seems, does the slime bother us enough to do something? There’s probably a study in there of how many days and what percentage of the lake is covered. In my view, however, we shouldn’t judge a solution based on how many days/hours the unit can be used. If we decided that algae was our chief problem, and we found a solution that cleared it up in (hypothetically speaking) just one day, I think that would be a greater success.
Just for a historical note – Worthington Park Superintendent A.J. (Hap) Ehlers, for whom Ehlers park is named, and Hap’s assistant, Daryl Gerber, used to go out in a rowboat each summer and go back and forth pouring bags of (I believe) copper sulphate in Lake Okabena. This was toxic to algae and it cleared the water but I believe it also is toxic to fish and I believe use of copper sulphate in lakes is now banned. I am uncertain of these details; maybe they even were using a different compound. I mention this because – if someone would want to pick up on this to learn the pluses and minuses – Daryl Gerber could be interviewed at his home on Humiston Avenue.
Thanks for the history on this Ray! It would be interesting to learn how well the copper sulphate worked. But, yes, my understanding is that it is now banned largely due to the negative effect on fish–though I heard that they would really bite when the copper went into the water. Would be fascinating to hear from Daryl.
Skimmer is a good plan but man hours required that adds expense. Think they should install some solar panel aerators . They run year round .I take care of wastewater ponds and toured a lot of facilities that have them.Seen great results on algae also it would help fish.Upstream runoff is solution the water shed is doing great job on.I don’t know much about upstream water demographics coming in to lake but think couple of spillways to help oxygen levels that would take some impurities out.
Lloyd, it would be quite interesting to know more about large-scale aeration. I’ve looked at aeration options for small ponds 1-10 acres and it seems to be very effective. It would be amazing we could aerate 800-acre Okabena. If you have any guidance, let us know.
Hi Jay, great article! I spoke to you regarding our Eco-Harvester last summer! It’s good to see that the community values the lake and agrees something needs to be done.
We also offer total lake aeration and it would be great solution long-term to managing your lake. We would be happy to put together a quote of installing if you like? In addition, aeration is just one tool for managing your lake and it would be a nice complement to the Eco-Harvester!
Let me know if I can be of any further assistance?
Mike Faber
Lake Weeder’s Digest
http://www.weedersdigest.com
763-551-1441
jay, great articles so far. one think i will say though, is that its easy to blame farmers for runoff but as mentioned many of the farmers already use best-practices. A large culprit that adds perhaps more directly to the algae in okabena is persons who live on or near the lake over fertilizing and using products on their properties that have no buisness being applied that close to a body of water. not sure if wgtn has done this, but some communities, to promote and improve water quality, completly ban applications of phosphorus based products as there are now much safer alternatives.
Justin, you’re absolutely right. While Lake Okabena may have more runoff coming from land used for agricultural purposes (Watershed Board told me 70% from Okabena Creek and 30% from in town), if we look at it on a per capita basis, in-town runoff challenges are substantially more significant. I’m not sure what’s been done in the past as far as a public awareness campaign goes, but there’s room to make significant headway on that front. I don’t think there’s anyone to blame. Everyone has been doing what they’ve done for decades and hopefully all these efforts can align as we develop a common goal.
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