In 2006, the year in which McHenry County Blog was begun, I noticed boats out on Crystal Lake doing something I had never seeen before.
I took some photos, discovered the people in the boats worked for the Illinois Geological Survey and published their findings.
Timothy H. Larson and B. Brandon Curry were from the Geological Survey and they, along with Nigel Wattrus of tthe University of Minnesota-Duluth, analyzed the data and wrote the paper
Unfortunately, good old Google labeled my work as a bad blog and wiped everything out, including that article.
Needless to say, my blog is no longer hosted by Google.
The team constructed a to construct a bathymetric map of Crystal Lake.
Back during my college days, I probed the bottom of the lake with a string and weight and found the deepest part was east of Rumsey’s Point, which is described as a “small peninsula.” I found it was 44 feet deep.
First the West End of the lake was examined.
From a north-south bar about two feet deep to the central north-south basin, which was six to seven feet deep.
The woman standing is Joan Thomason, the man is a worker from the city Crystal Lake.
Sediment ranged from less than a foot to.more than two feet.
The channel’s maximum recorded depths wre only 18 feet.
Eleivstion of Crystal Lake was 889.4 when the study was done.
“Over much of the northeast and east shore of the lake, the lake bottom dips very gently to about 4 to 6 ft depth where there is an abrupt steepening of the bottom slope to the deeper parts of the basin.”
483 soundings were taken.
Poles, a weighted line and an echosounder were used to determine the depth.
This boat came down from the University of Minnesota.
The outlet dam raises the water level one and a half foot.
“…the volume of water in the lake is 4,530,000 cubic meters at a surface elevstion of 889.3 feet.”
AI tells me that is 1,196,699,397 liquid gallons.
Crystal Lake showing shallow areas in 2006.
Crystal Lake West End contour map in meters. Xes mark where the sondigs were taken.
Red areas show regions of increase in sediment accumulation, blue areas show regions of sediment scour since soundings were made through the ice in 1990. Scour is the removal of soil, sand, and rock from seabeds by fast-moving water.
Crystal Lake depths east of West End in 2006.
Crystal Lake depths in 1957.
Crystal Lake east and west basins combined. Contour interval is 5 feet.
Although it is not in this report, I remember that part of a pine tree found at the bottom of the lake indicated it was 10,000 years old.
Photo credit: Tim Larson (ISGS retired) .
