Two Combined Sessions

Overview of Impacts of Motorized Watercraft on WI Lakes
Speaker: Tim Asplund


In 2000, I published a review of the Impacts of Motorized Watercraft on Wisconsin Lakes on behalf of the WDNR research program, which included studies that I had initiated in my role as a researcher in the 1990's, as well as my review of the current scientific literature.  In the intervening 20 years, I have continued to field questions and inquiries about this review paper and also track new information and research studies, even though my work focus has changed.  Fortunately, the information is still relevant and useful in helping address new issues and questions that have come up recently in regards to changing technology, increased recreational use, and navigating user conflicts.  In this talk, I will briefly summarize the findings of this review paper, provide examples of historical and recent research, and talk about management solutions that have been successful in addressing these impacts. 

Wave Propagation Dynamics and Water Quality Impacts on a Freshwater Lake in SE Wisconsin: North Lake, Waukesha County
Speakers: Capt. Tim Tyre, Mike Mortensen

The impacts associated with "wave enhancing" water craft (Wakeboard Boats) has become a concern for many lake residents. Damage to shorelines, subsurface impact to lake bottom sediments and water quality and effects upon other boats and lake users was studied in this Phase I research effort. A multi-agency effort was undertaken through the summer of 2020 to systematically measure wave propagation characteristics and their surface and subsurface impacts. Commercial drone technology was utilized to provide both aerial and underwater imagery. Sampling across 18 weeks of study during the 2020 boating season has produced preliminary findings revealing re-deposition of bottom sediments, plume effects during heavy boat usage times and clear differentiation between the "types" of waves produced by commonly used vessels on a typical freshwater recreational lake. Additional study is warranted and a science base is developed for lake management groups to address these concerns.