Zebra Mussel Sampler

Boat Launch AIS Inspection Hours

Aquatic Invasive Species (AIS) inspections are done May 1 - December 1 by DNR trained AIS inspectors during the following hours. The public boat launches are locked during non-launch hours.

May 1 – September 17
Daily:  6 am–10 pm

September 18 – October 9
Daily:  6 am–9 pm

October 10 – November 5
Daily:  7 am–8 pm, Inspector On-Call*

November 6 – December 1
Daily:  8 am–6 pm, Inspector On-Call*

*On-Call Program (October 10 - December 1)
FOR INSPECTIONS CALL (612) 499-3068 for Lake Calhoun and Lake Harriet or (612) 499-3072 for Lake Nokomis. After the inspection, the launch will be opened to allow boaters on to the lake. Boaters must call to be let off the lake and have a post-inspection. Boaters not exiting the lake by closing time must secure their boat and return for it the next day. 

Minnesota's waterways are threatened by a number of aquatic invasive species (AIS), which are not native to Minnesota and cause economic or environmental harm or harm to human health. Once an AIS is established it is nearly impossible to eliminate it. The Minneapolis Park and Recreation Board (MPRB) is taking steps to ensure that our water resources can be enjoyed for years to come by being committed to AIS prevention efforts. The MPRB has been actively monitoring AIS since the late 1980s when Eurasian water milfoil was first discovered in the Chain of Lakes.

While some of the City water bodies do contain AIS, such as Eurasian water milfoil, zebra mussels and common carp, there are several other species that have not yet established themselves here but are already in neighboring lakes and rivers throughout the state.

Visit the DNR's website for the most up-to-date infested waters list, detailed biological information and current regulations on aquatic invasive species. 

Aquatic Plant Management

Successful aquatic plant management is key to providing recreational opportunities in Minneapolis’ lakes. Plants that grow in and around water can have an impact on the long-term health of our area lakes. For this reason, the Minneapolis Park and Recreation Board (MPRB) completes aquatic plant surveys on Minneapolis lakes every two to three years. These surveys document the increase or decline in different species of aquatic plants.

View the MPRB Water Resources Report for detailed annual monitoring data, data collection methods, and more.

Management Methods


Biocontrol methods can be used to manage some aquatic plants. A beetle that feeds on the leaves of Purple loosestrife has been successful at controlling this invasive wetland plant species. Beetle populations can be impacted by harsh winters and may need to be supplemented throughout the years to remain effective.


Seed head and individual plant removal is used to help control some invasive plant populations including purple loosestrife and yellow iris. This labor and time intensive method of control can be effective over time.

mechanical harvester boat
Mechanical Harvester

Harvesting is currently the best management option that the MPRB has to control aquatic plants, including Eurasian watermilfoil, an aquatic invasive species that is prevalent in many Minneapolis lakes.

  • A boat called a mechanical harvester removes plants that are in the top six feet of water. This temporarily allows for trouble-free boating and swimming.
  • Divers using SCUBA gear hand pull plants in areas that are inaccessible or hard to reach with a mechanical harvester.
divers pulling eurasian watermilfoil
Divers Removing Eurasian Watermilfoil

Minnesota DNR issued permits limit the area of milfoil that can be harvested each year. Harvesting is done primarily in swimming areas and boat launches.



Species Currently Found in Minneapolis Waters

Eurasian Watermilfoil (Myriophyllum spicatum)

Curly Leaf Pondweed (Potamogeton crispus)

Purple Loosestrife (Lythrum salicaria)

Yellow Iris (Iris pseudacorus)

Flowering Rush (Butomus umbellatus)

Reed Canary Grass (Phalaris arundinacea)

Zebra Mussels (Dreissena polymorpha)

Chinese Mystery Snails (Bellamya chinensis)

European Carp (Cyprinus carpio) and Goldfish (Carassius auratus)

Species of Concern to Minneapolis Waterways

Brazilian Waterweed (Egeria densa)

Other Aquatic Invasive Species of Concern

Prevention Efforts

In order to aid the public in the prevention of the spread of AIS, the MPRB has implemented a watercraft inspection program. Effective April 15, 2013 ALL boats, watercraft and watercraft equipment passing through the public boat launches on Lakes Calhoun, Harriet and Nokomis will require inspections for aquatic invasive species. Boats launched from the shoreline are not required to have an inspection. Boat launches will be closed when inspectors are not on site; be sure to check for current boat launch hours prior to your visit.

In addition to watercraft inspections, MPRB also implemented the following actions to prevent the spread of AIS:

  • AIS education and outreach efforts
  • Lake usage data collection at the launches
  • Signage and additional trash receptacles to encourage proper bait disposal at launches, fishing docks, and high use shoreline fishing areas
  • Early detection monitoring
  • Staff education
  • Developing an AIS Rapid Response Plan for future Board adoption

AIS Prevention in the Future

Park Board staff will continue to evaluate and improve its AIS prevention program from year to year. AIS Inspectors will be collecting data during inspections to continue to help inform decisions about future efforts.


Under Minnesota law, it is illegal to transport aquatic plants and animals as well as water, to and from water bodies. Failure to comply with Minnesota AIS regulations can result in fines up to $1,000.

Help Protect Your Waters

If you are a lake user do your part to prevent the transport of aquatic invasive species from one lake, river or creek to another. Protect Minnesota’s waters by following the state aquatic invasive species laws.

You Must:
  1. Clean visible aquatic plants, zebra mussels and other prohibited species from watercraft, trailers, and equipment before transporting from any water access.
  2. Drain water from bilge, livewell, motor, ballast tanks, and portable bait containers before leaving water accesses or shoreline property.
  3. Keep drain plug out and water-draining devices open while transporting watercraft.
  4. Dump unwanted bait in the trash.
You May Not:
  • Transport aquatic plants, water, or prohibited invasive species such as zebra mussels or Eurasian watermilfoil.
  • Dump live bait into state waters, on shore, or on the ground.
  • Launch, or attempt to place, watercraft, trailers or equipment with aquatic plants, zebra mussels, or prohibited invasive species into any state waters.
Additional Recommended Precautions:
  • To remove or kill hard-to-see aquatic invasive species before moving to other water bodies the following is advised:
    • Spray with high-pressure water and rinse with very hot water and/or
    • Dry boats and water-related equipment for at least five days
  • Report new sightings of aquatic invasive species. If you suspect a new infestation of an invasive plant or animal, save a specimen and report it to a local natural resource office.

Additional AIS Prevention Information


What is the resolution for aquatic invasive species inspection?

When will inspections and launch hours be in effect?

Why is the Park Board concerned about AIS?

Isn’t it too late to prevent the spread of AIS?

Which AIS is the Park Board aiming to keep out of Minneapolis lakes?

How does the resolution affect canoes, kayaks and sailboats?

How was the inspection/launch season determined?

How long will inspections take?

What if I refuse to have my boat inspected?

Which lakes or water bodies will be affected by the AIS inspections?

What if I want to go fishing on the lakes before the launch opens or after it closes?

Can I use my gas powered motor on any of the lakes?

What is proper bait disposal and how does it protect against AIS?

What can I do to stop the spread of AIS?