Wakesurfing can Harm Lake Bottoms — Minnesota Phase II Study now out
The long awaited University of Minnesota Phase II study is now out and the results are not good for Wisconsin. We’re going to ask you to watch the 45 second video below before going further in this article. It depicts bottom impacts from a wake surf boat at a depth of 14 feet (turn the sound up to hear the boat go across the surface).
Ever since wakeboats began to show up regularly on Wisconsin waters a decade ago, we’ve been told by the industry and their supporters that claims of downward prop wash and wake scouring of the lake bottom were exaggerated. The rebuttals are familiar to many:
“That video of bottom scouring was shot in three feet of water, fishing boats do more prop wash scarring than anyone at those depths”
“We only wake surf in deep water, otherwise we can’t generate a wave, so don’t worry about it”
“Our trade group tells us ten foot depths are fine and that a computer modeled study they did confirms this”
None of the rebuttals above ever seemed to add-up given reports and videos we’ve received from around Wisconsin over the past two years. Nor do they line up with the Lake Waramaug study from December of 2024, where downward prop wash disturbed bottom sediment at a depth of 26 feet.
We’ve now got some significant new information courtesy of the University of Minnesota Phase II study, released this past week. The team at the St. Anthony Falls Lab (SAFL) has completed and published their work. You can read the full study and accompanying data HERE.
The most important conclusion is that wakeboats in wake surf mode should only be used in water depths 20 feet or greater. While all boats can impact the bottom, the wakeboat impacts are quite jarring when compared to the other types of watercraft tested. While the bottom videos only cover depths of 9 and 14 feet, the 20 foot recommendation was based on additional SAFL testing done in 27 feet of water. The study report goes on to say that the 20 foot buffer should be measured from the surface of the water to the top of any bottom vegetation where our fish population will many times reside.
Below is a video of a different model wakeboat blowing up the bottom in the study at a 9 foot depth. Note all the underwater vegetation blowing past the camera.
We’re certain the wakeboat manufacturers will eventually release a critique of the SAFL report, claiming some sort of bias or false testing protocols. But the videos above don’t lie. Wakeboats have a much greater negative impact on lake bottoms than the industry has ever been willing to acknowledge.
Why does the industry fight settled science on this topic? The answer is simple. They’ve sold untold millions of dollars of very expensive boats to people across the country and want to keep every inch of water open for wakesurfing. If wakesurfing was restricted to large lakes (greater than 1,500 acres) and very deep water, sales would suffer in Wisconsin.
There is another industry in Wisconsin, of far greater importance than wakesurfing, and that is the fishing community.
Fishing generates $2.3 billion of annual economic impact for the State, including an estimated 21,500 direct jobs per the WI DNR
As you watch the SAFL videos above and below, do you think fish nests and habitat could survive those blasts? Notice all the bottom vegetation being uprooted.
Are long dormant bottom sediments now being released into the water column?
Food for thought for our Governor, Legislators and the DNR as they continue to debate this topic. The future of our glacial lakes are indeed at stake.