Fall Lake Updates

Dane County Lake Management News

Welcome!

Labor Day has come and gone, and with it another summer is winding down. Kids are back in school, the water is cooling off, and fall weather is settling in.

This year, the Yahara lakes enjoyed pretty good water quality and clarity for most of the summer. But those clear conditions also encouraged plenty of filamentous algae (Cladophora). This stringy, slimy algae grows on plants and the lake bottom, and sometimes piles up into large mats. Staff worked throughout the summer to provide some relief, though floating algae is especially tricky to collect.

Stable water levels likely added to the algae growth as well, since the lake surface stayed fairly steady until August rains finally brought some fluctuations. Staff will continue to manage water levels within the summer range until November 1st, when we shift over to the winter goals.

Dave Rowe

Lake Management Supervisor

rowe.david@danecounty.gov

(608) 575-3375

Navigation Buoys and Public Boat Ramp Piers

As the boating season winds down, Dane County LWRD staff will begin removing navigation buoys from the lakes after October 15th. This process usually takes 2–3 weeks, depending on the weather. A big thank-you to everyone who reported buoy issues this summer—your help in spotting missing or moved buoys and channel markers makes a big difference!

Staff will also begin removing boat ramp piers on October 26th to prepare for winter.

We appreciate everyone’s cooperation as we wrap up another great season on the lakes!

Pier Pick Up Program

Pier Pick Up had another great summer this year—seven weeks of service on Lakes Monona and Mendota, and six weeks on Lakes Waubesa and Kegonsa. A big thank-you goes out to the local municipalities and lake associations who help make this program possible!

We did run into one challenge a few times: some residents placed shoreline material out for collection. Things like dug-up shoreline plants with roots, soil, rocks, or gravel are too heavy and can damage our equipment.

Examples of unacceptable material for pier pick up service

What’s okay to put out:

Aquatic plants
Driftwood
Dead fish or other lake-generated material

What’s NOT okay to put out:

Shoreline plants with roots
Soil, rocks, or gravel

If you’d like to clear aquatic plants from around your pier, you’re welcome to do so following Wisconsin DNR guidelines (up to a 30-foot corridor without a permit). We’ll gladly collect those aquatic plants too. You can find more details on the Wisconsin DNR Aquatic Plant Management website.

Thanks for helping us keep this service running smoothly for everyone!

Fall Floaters

As late summer and early fall arrive, one of the Yahara Lakes’ most common native plants—Vallisneria americana (also known as perch grass, water celery, or lake grass)—often breaks loose from the lake bottom and floats to the surface. This can happen from boat propellers, wind, and waves, sometimes leading to large mats of floating plants that can feel like a nuisance.

Mats of floating Vallisneria on Lake Kegonsa

Despite the mess, Vallisneria is a very beneficial plant. It provides habitat for fish and other aquatic organisms, serves as an excellent food source for migrating waterfowl, and helps trap sediment to improve water quality.

During the summer, the Pier Pick Up program is available to help remove nuisance floating plant fragments. As we move into fall, however, residents are encouraged to compost these plants, or dry them out and treat them like other yard waste if they wish to remove them.

What to do with Zebra Mussels on Piers?

As lakeshore owners pull piers and boat lifts out for winter storage, many will notice zebra mussels attached to the equipment. We get lots of questions each year about what to do with these invasive organisms.

You have a couple of options:

Remove them and place them in the trash for disposal.
Leave them attached—they will not survive the winter months.

⚠️ A quick reminder: zebra mussels have very sharp shells, so please use caution if you choose to remove them.

Winter Ice Ordinance Chp. 71

Since February of 2025, the Dane County Lakes and Watershed Commission has been gathering comments regarding possible changes to Dane County Ordinance, Chapter 71: Regulation of Icebound Inland Waters. Deputies from the Dane County Marine and Trail Enforcement Bureau, as well as Conservation Wardens from the Wisconsin Department of Natural Resources, provided the Commission with information on implementation of the current ordinance. As a result, the Commission recommended that Land & Water Resources Department staff reach out to the public, as well as local Fire & EMS Departments, to gather any comments they may have regarding the ordinance.

May–June 2025: Public Comment Period

More than 30 comments were received through the Land & Water Resources Department website and a public information meeting.

September 2025: Lakes and Watershed Commission Recommendation

The Commission recommended updating the ordinance

Focusing on personal safety
Practicality of flotation devices and compliance
Recognizing changes in motorized recreational vehicles.

Next Steps

Land & Water Resources Department staff will draft proposed changes to Chapter 71 of the ordinance.
Proposed changes will be reviewed by the Dane County Board as part of the formal amendment process.
The public will be invited to provide comments on the proposed changes before adoption.

Share the Lake News!

If you’ve enjoyed these updates and reminders, please encourage your neighbors and fellow lake users to sign up for the Lake Management e-Newsletter. We send it out at the start and end of the summer season, as well as when there are important announcements to share.

The Land & Water Resources Department also offers several other e-newsletters with regular updates on projects and programs.

Dane County Land & Water Resources Department Website