Back in 1987 mild-mannered Salt Creek, in a rare fit of pique, overflowed its banks and Venicized surrounding streets. This disaster inspired some smarty to propose using the 125 year-old Elmhurst Chicago Stone Quarry as a flood control reservoir. A swell idea: the monstrous hole in the ground — it averages 200 feet in depth and can accomodate 8,300 acre-feet of water — was just sitting around not doing anything. Normally the quarry is empty except for a couple of feet of water in the eastern “lobe” (the half to the east of the narrow stone wall that bisects it).
After Ike the Hurricane sent his mere crumbs up to northern IL, both halves were filled.
Here’s a picture from the DuPage County web site that shows the quarry as it usually appears:
Now here’s my photo from about the same angle, except I couldn’t go inside the grounds. I had to clamber up a fence topped with barbed wire, where I injured my arm in my selfless quest to serve you better.
I can’t do the math, not knowing what the heck an “acre-foot” is, but 8,300 x 200 average depth = lotsa water. To give you a better idea of the scale of this thing, here’s a grab of a Google satellite shot taken in more clement days. The aquamarine hand and smiley face indicate Salt Creek as it meanders to… oh, I don’t know… Oak Brook, I guess. The bloody red hand and frowny face indicate the spot from which I photographed the expanse of Ike Water. The shadows cast by the walls of the quarry give some idea of their height. Or depth, I suppose. Can a wall have depth?
Finally, here’s another graphic borrowed from the DuPage County web site (paid for, after all, with MY TAX DOLLARS), which shows the same stuff schematically.
Oh, what the heck, here’s one more photo, taken at great peril, of the other half of the reservoir. It was taken from the southeast corner of the western lobe, facing north by northwest. The concrete structure is a pumping station.
Ordinarily a canyon, it’s now a lake.
UPDATE: Okay, I looked it up. An “acre-foot” is a measure of water volume. It’s the amount of water you’d need to cover one acre under one foot of water. It comes to about 325,851 gallons of water. The number I found for the volume of the quarry is 8,300 acre-feet. Now get this: 8,300 times 325,851 = 2,704,563,300. Two point seven billion gallons.
Here’s another way to look at it, courtesy of Wikipedia: “As a rule of thumb in U.S. water management, one acre-foot is taken to be the planned water usage of a suburban family household, annually.”
ANOTHER UPDATE: I took some photos downstream from the quarry during the height of the rain and later when then waters had subsided a bit. You can see the photos as this post: CLICK ME NOW, NOW NOW!
Also, at this post, you will discover another photo of the quarry taken two weeks later: PLEASE CLICK ME AND SEE THE QUARRY PICTURE. PLEASE.