We were very lucky to get these Rock Tour aka Elmhurst Quarry Tour tickets. They are available online only one day every other year, and sell out in 3 minutes! My wife, not so lucky, as she came under the weather so I invited my bud Jeff.
Floods have plagued DuPage County for decades as it quickly developed. Seizing the opportunity, the county purchased the Elmhurst Quarry from The Chicago Stone Company in 1992.
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| The East lobe of the quarry. Notice the ‘keyway’ on the back left of the wall. |
Salt Creek, the notorious North/South conduit that wreaks havoc when its banks overflow is no ‘babbling brook’. It averages over 12 feet wide and crests at over 13 feet. Engineers, whose areas of expertise include a wide range of environmental sciences, have done a fascinating job of collecting and returning rainwater to the creek during and after ‘rain events’…big and extended downpours. These water control wizards are passionate and proud of their work, as they should be. Let’s begin.
Salt Creek levels are monitored and water is manually released through a 7’X7’ sluice gate when it reaches a pre-determined level. The water flows Eastward through large channels at up to 700,000 gallons per minute! It continues until the water hits a ‘vertical drop vortex’ where the water falls 80 feet and flows under Route 83, a busy six-lane road. From there water splashes into an opening and enters the West lobe of the quarry.
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| The Vertical Drop Vortex |
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| The Sluice Gate |
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| The West Lobe |
The water then flows down the spillway and under West Avenue which divides the lobes, and enters the East lobe of the quarry through a ‘keyway’. The East lobe is 200 feet deep and can hold 2.7 billion gallons of water. After a couple of dry days, sediment and pollutants sink to the bottom of the quarry, and four 500 plus horsepower pumps begin to return the water back under Route 83 to Salt Creek. Since the water was stagnant, oxygen is restored to the creek via a large ‘staircase’.
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The staircase where oxygen is reintroduced and returned to Salt Creek.
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Both sides of the quarry have been filled before. We caught a peek of this in 2008 before a public viewing area was set up. In this condition, it takes 72 days to empty the quarry, although 10-15 feet of water is always left to accommodate the fish, and to mask odors created from pollutants sinking to the floor.
I feel like a ‘creek geek’ now, and will definitely be checking out the creek levels and the quarry when the next rain event arrives.
For an excellent and more thorough video presentation, visit
