Rock Lake



RLIA Recommendation to the City Council on Water Levels
click here
Thinking of Shoreland Changes? Read this first…
Waterfront Landowner Reference Guide
Rain Barrel Workshop
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Add a Shoreland Garden or Rain Garden to your Rock Lake property! Check the Healthy Lakes website ( and contact Zach Nagel at the Jefferson County Land and Water Conservation Department for next steps and financial assistance (  920-674-7111).

View the ‘Lake Lot 101 Workshop’ featuring experts that address a variety of concerns about our lake’s shoreline.   ⇒   ⇒   ⇒   ⇒   ⇒   ⇒   ⇒   ⇒   ⇒

Lake Capacity Issues: “On certain weekends & holidays, Rock Lake experiences an amount of boat traffic which exceeds common safety standards.” View our letter to the City Administration.

Miljala Tributary Restoration Project latest updates.

“Welcome to Rock Lake” area information with a map, created by the Joint Rock Lake Committee.

Beach Water Quality Testing Results for Sandy Beach, Bartel’s Beach, Tyranena Park, and Ferry Park can be found here:
If the E. coli in the water exceeds 235 cfu/100 ml, then an advisory sign is posted at the beach. If the E. coli in the water exceeds 1,000 cfu/100 ml, then a beach closure sign is posted. To find out more about beach water sampling, advisories, closures, and E. coli see: Beach Advisories, Closures and Human Health

Rock Lake Clean Boats, Clean Waters – see how many people were contacted and what lakes they came from; data from 2016 to 2021.

Harmful Algal Blooms in Wisconsin’s Lakes…they may look like thick paint floating on the water and frequently give off a foul odor… Further information on Blue Green Algae blooms are at:

Swimmer’s Itch; is neither dangerous nor contagious, but it is very uncomfortable.

Check these Boating Safety Tips put together by the Joint Rock Lake Committee

City Drains that Flow Directly to our Lake (Map)

Map of the Rock Lake Watershed, see what a drop of rain flows through to get to the lake.

Aerial photo of Rock Lake, 1994, Robert T. McCoy Photography.

Aerial Winter Photo, Rock Lake, March 2013, Stan Smoniewski

Korth Park – All about the history and ecosystems of this treasure that contains 1300 feet of shoreline, 89 total acres of land.

RLIA Suggestion for Odor Reporting for Daybreak Foods