When Good Lakes Go Bad

By Gary Mittelbach

A recent article in MLive shows just how much it can cost to control invasive plants once they invade and take hold in a lake https://www.mlive.com/news/kalamazoo/2023/03/portage-readies-to-begin-five-year-effort-to-clear-austin-lake-of-invasive-plants.html . Residents of Austin Lake in Portage (MI) are going to spend $117,445 in 2023 and up to $450,000 over the next five years in efforts to reduce the abundance of invasive plant species (including Eurasian Milfoil and Starry Stonewort) and other nuisance weeds in their lake. The volunteer organization the Austin Lake Riparians worked with the Portage City Council to form a special lake assessment district with the power to assess Austin Lake property owners the cost of treatment (herbicide treatment for invasive species and mechanical harvesting of nuisance levels of native plants). With 438 parcel holders around the lake, the average Austin Lake property owner will pay about $200/yr.

There are some parallels and some important differences between Austin Lake and Gull Lake. Both are relatively large lakes (Austin Lake is 1,133 acres while Gull Lake is just over 2,000 acres). However, Austin Lake is much shallower than Gull Lake, with an average depth of 5ft and a max. depth of only 11ft (Gull Lake max. depth is 110 ft). The deep, cold waters of Gull Lake and its low nutrient status (see https://glqo.net/portfolio-item/water-quality-committee/) help protect Gull Lake from the nuisance level of plant growth found in Austin Lake. However, Gull Lake does have three of the nasty invasive species found in Austin Lake (Eurasian Milfoil, Starry Stonewort, and non-native Phragmites), albeit at low abundance. The Gull Lake Quality Organization (a non-profit, volunteer organization funded by member dues and donations) contracts with Progressive AE, the same firm handling the invasive species treatments in Austin Lake, to monitor and treat with herbicides the invasive species in Gull Lake.

The GLQO currently spends about $12,000 per year for monitoring and treating invasive plant species and another $17,000 per year staffing and maintaining the boat wash at Prairieville Park public landing. The boat wash is an important tool to help keep invasive plant species from spreading into and out of Gull Lake. So far, these treatments have kept the invasive plants in Gull Lake “under control”.  But, the clear message from Austin Lake and other lakes in our area is this – “Be vigilant and don’t let invasive species get the upper hand, for if you do it’ll cost you – big time”!

You can read about the GLQO efforts to control invasive species in Gull Lake in our Fall 2022 Newsletter.