Onterra is currently working on waterbodies in nearly 20 counties in Wisconsin. These projects include studies and surveys on lakes ranging from 6,500 acres to less than 60 acres, chains of lakes with over 20 waterbodies, and several town-wide projects. Some are management planning projects while others are implementing a plan Onterra assisted in creating. A few projects investigate a specific issue on a lake, like internal nutrient loading, and others focus upon general monitoring of the lake’s environment to build long-term datasets.
Below we have highlighted several of our current and recent past projects. While there are similarities between many of our projects, each is unique because each lake is unique.
Below, we have provided brief summaries of some of our more recent projects. The final project deliverables can be viewed on the respective Wisconsin DNR Find-a-Lake page by clicking on the project title. Additional project summaries will be added regularly to this page, so please check back occasionally to learn more about our work.
Lake Puckaway is a shallow, 5,039-acre lake with a vast watershed of over 442,000 acres. The lake is considered hypereutrophic and, in many years, the water exiting the lake is of worse quality than the water entering the lake. This project was funded with three Wisconsin DNR grants and took over two years to complete. The resulting plan addresses management challenges for the lake and lake district. The Lake Puckaway Protection and Rehabilitation District is currently partnering with Ducks Unlimited, the Wisconsin DNR and Green Lake County to implement a portion of the lake’s plan by rebuilding a dredgebank that once existed in the lake in order to reduce wind-induced sediment resuspension and the associated impacts on aquatic plants.
During 2016 and 2017, Onterra worked with the North and South Twin Lakes Riparian Association to update the group’s 2006 management plan. Much of the focus of the updated plan is on managing an expanding Eurasian watermilfoil population in both lakes. Completion of this plan in 2018 ensured the eligibility of the newly-formed North and South Twin Lakes Protection and Rehabilitation District to apply for state AIS control grants.
The Crystal Lake Club partnered with the Marquette County Land and Water Conservation Department to sponsor a Wisconsin DNR Lake Management Planning Grant in 2017. Crystal Lake is a deep (60 feet), spring-fed, headwater drainage lake of 119 acres. The project was spurred over concerns of marl sedimentation and heavy growth of Chara and hybrid watermilfoil. A primary objective of the planning process was to inform riparian stakeholders of realistic management actions that could be used to ensure recreational use of the lake.
Onterra assisted the Lake Iola Lake District in creating the lake’s first management plan in 2008. A water level drawdown was completed during 2011-13 to complete dam repairs and install a lake drain pipe. The district contracted with Onterra to update the lake’s management plan to account for the changes the lake faced following the drawdown. The management plan addresses issues with nuisance levels of native plants through mechanical harvesting and herbicide applications. It also includes periodic assessments to track AIS populations.
The completion of the North and South Twin Lakes Comprehensive Management Plan (2018), provided the North and South Twin Lake Protection and Rehabilitation District the general framework for managing Eurasian watermilfoil (EWM) in the system moving forward. This project built off that framework, and the specific details for 2019 monitoring and management plan. The planning discussions and partner collaboration involved within this process were arguably as important as the written deliverable.
The Silver Lake Management District initiated a 3-year Eurasian watermilfoil control project that included a whole-lake pelletized fluridone treatment strategy in 2016 with integrated pest management (IPM) activities, consisting of contracted hand-harvesting efforts, being conducted in 2017 and beyond. This report discussed the implementation planning and the pre/post aquatic vegetation monitoring of the control strategy. This report also proposed the next stage of management, which has resulted in a much-lowered EWM population in the lake to date.
The Musser Lake Comprehensive Management Plan (2013) outlined a management goal to control curly-leaf pondweed (CLP) within the flowage. During the fall of 2013, the Price County Dams Department needed to lower the system’s water levels by 6 feet. Discussions within the Musser Lakes Association, the Price County Dam Tender, the Wisconsin Department of Natural Resources, and Onterra lead to a plan to retain the lowered water level through winter in an effort to impact that flowage’s CLP population. This report documents the monitoring of this winter water drawdown through 2015.
In 2014, the Pigeon Lake Association of Manitowoc County completed a comprehensive management plan with Onterra’s assistance. A primary goal of that plan was to create a hybrid watermilfoil (HWM) control strategy if the lake’s population continued to increase. Following additional monitoring and education, the association moved forward with a large-scale treatment during spring 2017. The large-scale treatment was highly effective in controlling HWM, with no HWM being located during the year of treatment (2017) or the year after treatment (2018). While some impacts to the native aquatic plant population were noted, the magnitude of decline was less than anticipated by Onterra and less than was discussed with the PLMC during the pretreatment risk assessment. Onterra crews located a single HWM plant in 2019, which was removed via hand-harvesting. No HWM was found during surveys completed in 2020.