1. Our hot dry summer continues. Since June 1, Wonder Lake has received a total of 14 inches of rainfall, as measured at the USGS Thompson Road gage. Fortunately, 10 of those inches of rainfall have occurred since early August, so we might be getting into a wetter period to help improve flow through the lake. With more rain, and as temperatures start to cool down as we move into fall, it is hoped that the algae blooms will begin to finally fade away.
1. Northern McHenry County is still the ONLY location in the entire eastern United States that is under extreme drought. According to data released by the National Weather Service, the month of June 2021 was the fourth-hottest June ever recorded in Chicago’s history. Based on long-term climate averages, from April 1st to today, the amount of expected rainfall at Wonder Lake would be 13.7 inches. Instead, for this same period, the USGS rain gage at Thompson Road only recorded about 6.1 inches.
1. As everyone knows, most of McHenry County is experiencing a severe drought. Based on long-term averages, over the last two months, the amount of expected rainfall would have been over 8.5 inches. Instead, the USGS rain gage at Thompson Road only recorded 1.75 inches of rain over that two-month period. This lack of rainfall, which is even more extreme in the Nippersink Creek watershed above Wonder Lake, has resulted in the stream flow into Wonder Lake dropping from an average of around 60 cubic feet per second (CFS), to less than 18 CFS.
1. On April 15th, with the cooperation of the Woodstock Fire/ Rescue District, the Wonder Lake Fire Protection District and Hebron-Alden-Greenwood Fire Protection District performed a controlled burn at the Wonder Lake Sediment Drying Facility on Greenwood Road. Conducted as a FPD training exercise, this burn was done at the request of the MPOA, to burn off undesirable vegetation growing in the highly fertile dried sediment. Thanks to all involved for getting this accomplished.
1. The three islands on the east side of the lake (O’Brien Shoals North & South and Wickline Island) previously had rip-rap installed offshore as a collar to help break up wave action before hitting the unprotected shoreline soils. While these practices have been very successful in creating quiet water areas, there is still more work needed. We are beginning to explore developing plans for adding additional erosion control protection around the islands, removing undesirable vegetation while replacing it with desirable native species, and improving fishery habitat.
1. Lake users are reminded that with the recent thaw, any remaining ice surface should be considered unsafe.
2. In addition to the state-required annual inspection of the Wonder Lake Dam, the MPOA has retained the engineering firm (CBBEL) that conducts those inspections to also prepare a report on the Wonder Lake Dam and Spillway. The scope of that study is provided below. A draft version of that report has been received, and is currently under review, it is hoped that the final report can be available for distribution in the next month or so.
CBBEL SCOPE OF SERVICES
1. Lake users are reminded that with the deeper water now present in the dredged portions of the lake, ice formation on the lake can be inconsistent, particularly where streams flow into the lake. Please use caution accessing the lake unless you are positive of safe ice conditions.
1. The annual inspection of the Wonder Lake Dam and the Wonder Lake SDF was conducted by the MPOA consulting engineers on Friday, October 9th. The engineers were pleased with the concrete repair work that was done on the spillway during the Fall 2019 lake drawdown. Their summary report will be forwarded to the IDNR-OWR, as required.
1. The 2019 drawdown of Wonder Lake is now officially over. As of the beginning of December, water again began flowing over the dam spillway, allowing the sluice gates to again be fully closed. It is still expected that the lake level will still rise a bit more, as it usually maintains a normal pool from 3 to 6 inches above the spillway crest.