Submerged aquatic plants, often dismissed as “weeds,” are essential to the freshwater ecosystems of lakes and rivers. Known scientifically as macrophytes, aquatic plants absorb nutrients like phosphorus and nitrogen which otherwise can fuel algal blooms. They also stabilize lake-bottom sediments, help protect shorelines from wave erosion, and provide critical habitat and food for fish and other wildlife. Because aquatic plants play such a vital role, the Wisconsin Department of Natural Resources (DNR) regulates and limits their removal to preserve the numerous benefits they bring to our waterways.
2026 Frozen Assets — The Coolest Yet!
Thank you for helping make Frozen Assets unforgettable!
Thank you for helping Clean Lakes Alliance turn frozen lakes into a full-on celebration! Our annual Frozen Assets Festival and 5K Run/Walk brought people together and put winter lake appreciation front and center.
2026 Frozen Assets Festival
February 7 @ 10:00 am – 3:00 pm
About the Frozen Assets Festival
Join Clean Lakes Alliance on Saturday, February 7, from 10 a.m. to 3 p.m. for Frozen Assets, with Presenting Sponsor CG Schmidt and Hosting Sponsor The Edgewater, and many other sponsors! The family-friendly festival on frozen Lake Mendota at The Edgewater connects the community with the lake through free winter activities.
Festival attendees can see skydiving, figure skating, dance, science, large show kite demonstrations, and the legendary Mary B ice boat. Guests can also participate in an Indigenous Snow Snake Contest, try pond hockey and snowshoeing, and enjoy free ice skating and hot chocolate, among other activities.

The day begins with the annual Frozen Assets 5K Run/Walk on frozen Lake Mendota. Whether you run, walk, ski, snowshoe, skate, or even ride in a sled, participants experience the thrill of crossing frozen Lake Mendota for a good cause. Registration includes admission to the 5K, a winter stocking hat (while supplies last), and post-race beer (21+) courtesy of Wisconsin Distributors. Kids ages 10 and under may participate for free with a registered adult. Proceeds support efforts to protect and improve the lakes, lands, and waters of the Yahara Watershed.
Each year, this FUNraiser, FRIENDraiser, and FUNDraiser highlights the year-round value of our lakes, while raising funds for lake improvement projects, educational programming, and volunteer water quality monitoring.
When the lakes freeze in Greater Madison, they become our largest parks. Clean Lakes Alliance encourages community members and visitors to experience these “frozen assets” and appreciate their importance, even in the middle of the winter. For more information about Frozen Assets, including event details and times, please visit: cleanlakesalliance.org/frozen-assets/#Schedule.
Related Events
2025 Water Quality Monitoring Results
LakeForecast water quality monitoring in 2025
Clean Lakes Alliance’s LakeForecast water quality monitoring program completed its 13th season in 2025. This program is entirely volunteer implemented, with more than 100 trained monitors assessing water quality conditions from nearshore and offshore locations across all five Yahara lakes (Mendota, Monona, Wingra, Waubesa, and Kegonsa).
From Memorial Day through Labor Day, volunteers recorded water clarity, air and water temperature, waterfowl presence, the extent of floating plant debris, and the severity of green algae and cyanobacteria at public beaches, lakeside parks, and private piers. Submitted condition reports were able to be tracked in real-time on Lakeforecast.org or our free app, allowing the general public to stay up to date on current lake conditions.
What’s Behind Winter’s Loudest Lake Sounds
Lakes can be surprisingly noisy in winter. Ice fractures and cracks are constantly forming through these cold winter months, causing audible sounds ranging from a slight echoing “blooop” sound to a startling or explosive “bang!” Why exactly are our icy lakes so loud?
Ice isn’t always as solid as it looks
Although lake ice appears stable and solid, it is an ever-shifting material subject to ever-changing forces. Unlike nearly every other substance or material, the volume of water significantly expands as it freezes, increasing the given volume of water about 9% after freezing. The expansion can induce incredible amounts of pressure onto the ice. Think about how frozen water can cause metal pipes to bend and burst.
When will the lakes freeze? It’s complicated.
The brisk air is a reminder that our local lakes will soon freeze, but predicting when is anyone’s guess. There is a complex interplay of many forces that uniquely influences each lake’s ice-on date. (Learn more about the Mendota Freeze Contest and make your guess for when Lake Mendota will freeze.)
Freezing air temperatures are obviously the driving force behind lake ice formation. Yet water has a high specific heat capacity. This means it takes a lot of energy to change the temperature of water compared to other materials. Therefore, air temperatures from much earlier in the season can impact timing of ice formation. A cool September, for instance, can set the stage for an earlier freeze.
Thank you! 2025 Frozen Assets a success!
Thank you for helping make Frozen Assets a week to remember!
Thank you for helping make the 2025 Frozen Assets Festival and 5K Run, Walk, and Skate one of the best ever! Throughout the week, Frozen Assets not only brought the community together, but it also educated people and raised awareness for our number one asset – the lakes!
Frozen Assets 5K Run/Walk
February 8, 2025 @ 10:00 am – 12:00 pm
Frozen Assets 5K
Join us on Saturday, February 8th, 2025, for the 6th annual Frozen Assets 5K Run/Walk with Major Sponsor Associated Bank and Hosting Sponsor The Edgewater. Shake up your fitness routine and experience our lakes from a whole new perspective – from frozen Lake Mendota! The Frozen Assets 5K Run/Walk truly is a bucket-list experience – this event is one of the only races worldwide to be held ENTIRELY on a frozen lake.
Your registration in this event raises important funds for lake improvement projects, water quality monitoring, and education!

Event details
Day: Saturday, February 8th, 2025
Time: 8 – 9:30 a.m. check in | 10 a.m. start
Location: The Edgewater & frozen Lake Mendota (*New in 2025 – if ice conditions are inadequate, the 5K will be moved to a land course)
Course: The 5K course begins off the end of The Edgewater’s pier. Runners and walkers will head out toward Picnic Point, past the Memorial Union, before looping back and finishing at The Edgewater.
Registration cost:
$45 for walking/untimed participants
$55 for chip-timed participants
FREE for children 10 & under with purchase of adult registration
Participants receive a super soft t-shirt, courtesy of Lands’ End, and participants 21+ will receive a post-race beer, courtesy of Michelob Ultra.
EVENT FAQS: cleanlakesalliance.org/frozen-assets/#5K
Thank you, sponsors!

Frozen Assets Festival
February 8, 2025 @ 10:00 am – 3:00 pm
Frozen Assets Festival
Join Clean Lakes Alliance on Saturday, February 8th from 10 a.m. to 3 p.m. for Frozen Assets, with Hosting Sponsor The Edgewater! The family-friendly festival at The Edgewater helps connect the community with the lake through free winter activities. Festival attendees can see large show kites, science demonstrations, and try ice skating and snowshoeing. Festival goers can also enjoy free hot chocolate and more!
Each year, this FUNraiser, FRIENDraiser, and FUNDraiser highlights the year-round value of our lakes, while raising money to protect our waters through lake improvement projects, educational programming, and our volunteer water quality monitoring program. When the lakes freeze in Greater Madison, they become our largest parks. Clean Lakes Alliance hopes community members and visiting guests can interact with our “frozen assets” and appreciate their importance, even in the middle of the winter.
Saturday, February 8th, 2025 (10 a.m. – 3 p.m.)
The Edgewater & Lake Mendota
FREE, open to the public

All-Day Events (Saturday 10 a.m. – 3 p.m.)
2025 Ice and Snow Sailing World Championships, Lake Mendota
Kites on Mendota with Wisconsin Kiter’s Club, Lake Mendota
Free hot chocolate, Grand Plaza
Free ice skating and free skate rental, The Edgewater Ice Rink and Skate Shop
Try snowshoeing, Lake Mendota
Explore how UW-Madison Center for Limnology monitors our lakes in the winter months, Lake Mendota
Play Plinko (Lake-O), Nolen Gallery
Spin the Price is Right Wheel, Nolen Gallery
Snow Snake with members of Ho-Chunk Nation, Lake Mendota
WI Salt Wise booth – hear about how salt use can impact our lakes, outside
More events to be announced!
Scheduled Activities (Saturday, February 8th)
8 – 9:45 a.m. Check in for Frozen Assets 5K Run/Walk, 5th Floor Registration Tables
10 a.m. Frozen Assets 5K Run/Walk begins, Lake Mendota off The Edgewater Pier
10 a.m. – 1 p.m. UW Physics “What’s Colder Than Ice?” Lake Mendota
10:30 a.m. – 1:30 p.m. IceCube demonstrates Space Dust & Neutrinos, Outside
2:00 p.m. Clean Lakes 101 family-friendly science presentation, “Frozen Frontiers – Secrets of Life Beneath the Ice,” The Edgewater Grand Ballroom C
More events to be announced!
About the Festival
Join Clean Lakes Alliance at The Edgewater for the Frozen Assets Festival! We’ll have FREE, family-friendly activities on frozen Lake Mendota! Thank you to our hosting sponsor The Edgewater, and our other sponsors for making this community event possible.
The Frozen Assets Festival will kick off with the Frozen Assets 5K Run/Walk, held entirely on the ice in front of The Edgewater. The rest of the day will include family-friendly activities on the ice and The Edgewater Plaza.
Thank you, sponsors!

2024 Water Quality Monitoring Results
LakeForecast water quality monitoring in 2024
Clean Lakes Alliance’s LakeForecast water quality monitoring program completed its 12th season in 2024. This program is entirely volunteer-implemented, with over 100 trained monitors assessing water quality conditions from nearshore and offshore locations across all five Yahara lakes (Mendota, Monona, Wingra, Waubesa, and Kegonsa). From Memorial Day through Labor Day, volunteers recorded water clarity, air and water temperature, waterfowl presence, the extent of floating plant debris, and the severity of green algae and cyanobacteria at public beaches, lakeside parks, and private piers. Submitted data can be seen in real-time on Lakeforecast.org or our free app, allowing the public to stay up to date on current lake conditions.



