cautionNew Ice with Variable Temperatures Forecast - Please use extreme caution. Lake users should view ice safety practices prior to lake use:


August 4, 2020 -- In late June, the MPOA received reports of a submerged obstruction which had been struck by passing watercraft, on the east side of the lake, just southwest of Wonder Lake Marina. The object was apparently partially buoyant, capable of bouncing and drifting along the lake bottom. The MPOA and Wonder Lake Fire Department Dive Team subsequently coordinated a search for the object, using a boat equipped with side scanning sonar. Despite a number of attempts to locate the object, it could not be found. At this point, it can only be assumed that the object finally sank to the lakebed, and/or drifted into deeper water. However, anyone boating in the general vicinity of Wonder Center Beach should still use caution, and contact the MPOA if anything is encountered.


The MPOA Office will allow in-person processing of MPOA watercraft decal sales.

The MPOA office re-opening is based upon the following conditions, and CDC guidelines.

  1. Masks must be properly worn at all times. No mask will mean no entry / no service.
  2. To allow for social distancing, only one person will be allowed in the MPOA Office at one time. You will be let in individually one by one.
  3. Have all required documentation, payments, and proper identification ready.

Please note that anyone who had acquired MPOA watercraft decal(s) in 2020 will have their 2021 Decal application mailed to them in mid-January, 2021. Bringing that paperwork in will greatly expedite your decal purchase. If not available, and if requested by sending an email to a duplicate application will be USPS mailed, To avoid crowds / delays, it is still strongly recommended to apply for your decal(s) by US mail.

The MPOA appreciates everyone’s patience and cooperation in getting decals sales back up to speed in this unprecedented situation


Please note, that although Wonder Lake is a private lake, the subdivision swimming beaches found around Wonder Lake are, under state law, considered public beaches, subject to the regulation of the Illinois Department of Public Health (IDPH) and McHenry County Department of Health (MCDH). However, this does not mean they are open to the general public. Only residents of each Wonder Lake subdivision with a swimming beach are allowed to use them.

In addition, the COVID-19 related swimming beach guidance being provided here by IDPH and MCDH only applies to those public (subdivision) beaches; not to anyone swimming on their lakefront property or from watercraft on the lake.

As always, under any circumstance, lake users are encouraged to not swim in the lake after heavy rainfall events, as that is usually when water quality issues can arise, and when subdivision beach advisories or closures occur. Once MCDH resumes its routine swimming beach water quality monitoring (as discussed below), lake users are encouraged to view the posted water quality results for their subdivision beach, or one near their lakefront property, at:

From the McHenry County Department of Health

There has been a recent development regarding the beach operation during Phase 3 of the Restore Illinois plan issued by the Office of the Governor in response to the pandemic. A representative from the Illinois Department of Commerce and Economic Opportunity has confirmed that beaches will be able to operate during Phase 3 under guidelines from Illinois Department of Public Health (IDPH) which are anticipated to be released soon. Once guidelines are established they will be available for review at the following address: . Please note these guidelines will likely be listed under the Outdoor Recreation section.

In anticipation that the IDPH swimming beach operation guidelines will be available shortly our Department will be conducting water sampling at all the McHenry County Beaches which have historically participated in our sampling program on Monday June 8, 2020.

Beach inspections will also be conducted starting on June 9th for any beaches which are ready for inspection at that time. Please notify us if you anticipate your beach will not be ready for the annual inspection by June 9th.

The official opening of beaches will be dependent on the release of the IDPH swimming beach guidelines and your ability to meet the guidelines. In addition please be reminded that beaches must also be in substantial compliance with the IDPH Swimming Facilities Code including satisfactory sampling results prior to opening for the season. You will also need to renew the bathing beach license(s) through IDPH if you have not already done so. If you have any questions or need additional information regarding your license renewal, you can contact the IDPH at phone number 217-782-5830 or email:

The revised 2020 routine schedule for MCDH beach sampling is anticipated to be as follows:

  • June 8th, June 23rd and June 30th
  • July 14th and July 28th
  • August 11th and August 25th



WELCOME to the Master Property Owners Association (MPOA) in Wonder Lake, Illinois 60097. The MPOA owns and manages Wonder Lake, a private 830 acre recreational lake located northwest of Chicago. The MPOA office is located at 7602 Hancock Drive, at the northwest corner of Hancock Drive and E. Wonder Lake Road, roughly two miles north of IL Route 120. Do you have a question about the Lake, or need information about the Wonder Lake area? E-mail:, Phone: (815) 653-1000


The two primary reasons watercraft are prohibited from using the lake during lake closure is to protect the shoreline from wakes and protect the people and watercraft from floating debris. The Lake Use Commission reviewed this procedure and concluded that non-motorized vehicles, canoes, kayaks, etc. do not make a wake and travel slow enough that they should be able to see and avoid floating debris. It is therefore the recommendation of the Lake Use Commission that future Lake Closure notices will prohibit the use of motorized vehicles.


Dredging is now complete and equipment / pipes are being removed. (restoration of areas disturbed by the dredging equipment will take place in 2019). Fun fact: 516,265 cubic yards of sediment were removed from shallow areas of the lake. This is the equivalent of about 29,000 dump truck loads!

•  NEW  LATEST UPDATE → Lake Managers Report
• Read about the History of Wonder Lake's Restoration
• EROSION CONTROL BARRIERS: Read 2012 Notice to Lake Users


You can take boat safety classes online, at anytime: Boater, and are fast and easy and certification cost is $29.95. Persons at least 12 years of age and less than 18 years, without an Adult are required to have a certificate. As lake use on Wonder Lake is largely governed by Illinois Department of Natural Resources regulations, it may be useful to periodically review information related to those regulations. Information can be downloaded at:


Lake users are reminded that MPOA Lake Use Decals MUST be permanently affixed to the watercraft / snowmobile / ATV  to which they are registered, and that they are NOT transferable. The Wonder Lake Police Department Marine Patrol is provided with a list of all MPOA Decal registrants, and the specific type and description of the unit each decal number was issued to. Failure to have your MPOA decal permanently affixed is a ticketable offense. 2020 Decal Form

  • ALL WATERCRAFT 1- 39 HP $20-



• Senate Bill 3434 allows for the seizure of a watercraft used in the commission of certain offenses related to operating under the influence. The new rules bring penalties for boating under the influence more in line with those for operating a motor vehicle while impaired by drugs or alcohol. 

• Senate Bill 3433 requires all persons born after Jan. 1, 1998 to take and pass a boating safety course validated by the Illinois Department of Natural Resources and hold a valid boating safety certificate before they can operate a motorboat with an engine over 10 horsepower.

• Senate Bill 2731, mandates that the operator of any watercraft that is towing a person, such as a water skier or tuber, must display a bright orange flag measuring not less than 12 inches per side. The flag must be displayed from the time the person to be towed leaves the boat until that person returns to the boat at the conclusion of the activity. 
Under the law, flying the flag for purposes other than towing is prohibited, so be sure to only display the flag when towing.