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Posted on July 9, 2019 at 9:24 AM by Ryan Hiniker
Drainage update 7/08/2019
Upcoming Drainage Hearings or Meetings:
As many of us southern Minnesota lake dwellers know, things can get a little green and stinky on some of our lakes during the warmer summer months. The common reason for this is thick blooms of algae. The algae quickly feast and multiple by a sudden influx of phosphorus in the water. The water-soluble phosphorus is thought to be released from the muddy bottoms of our lakes. The lakes will often contain nutrients and sediment that contain forms of insoluble phosphorus that will stick to their muddy bottoms until conditions are just right.
Unfortunately, conditions are just right for this phosphorus release about the same time as we want to be out on the water. As temperatures rise during the summer months it will also raise the lakes water temperature. Warmer temperatures bring on more weed growth, the combination of warmer water and additional weeds leads to a depletion of oxygen in the water that can sometimes turn anaerobic. Usually when this happens, we will notice more dead fish and larger areas of algae growth, sometimes toxic algae spores.
Many lake groups and associations across the State of Minnesota are joining in the fight to clean up their area lakes. To my knowledge, there is no “Silver Bullet", used to get a lake completely free of algae and crystal clear. Many lake associations have tried large combinations of things to help clean up algae and water clarity issues on their individual lakes. Locally we know of groups using floating islands with plants that act as natural filters for the lake. Carp netting, bubble aeration systems and other shore land efforts are just a few things that are having great results locally.
I did come across an article that spoke of company that is using Aluminum Sulfate to treat algae blooms. So, think back to high school chemistry class with positive and negative charged ions. The aluminum sulfate acts as a blanket to the phosphorus on the bottom of the lakes. The aluminum sulfate can be a very effective way of treating lakes with serious algae issues, but it can’t be resolved by a chemical treatment alone. All in-coming waters to a lake also need to be treated or addressed for phosphorus and nutrient pilling. Adding more grasses along shorelines, keeping storm sewer drains clean of leaves and fertilizer, and reducing sediment will also help reduce phosphorus. The aluminum sulfate application is more of a band-aid than a permanent fix to the lake’s ecosystem. This application is not cheap, but is a sought-after option for many area lakes. For more information click on the link. https://www.mprnews.org/story/2019/07/05/algae-lake-chemical-treatment
Recent Drainage Inspections – week of July 1 – July 5:
Hope that everyone had a safe and wonderful Fourth of July.
Special note that the blog will be moving to a Tuesday posting in the near future. So, same great blog just being posted one day later on Tuesdays.
We require that all repairs to a county drainage system (tile or open ditch) be authorized by one us in the drainage office, either Craig or myself, before any repairs are made.
Drainage Management Specialist