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| Street View, Oct 2015 |
USACE, Rock Island District posted two photos with the comment:
Today's edition of 'Then & Now' takes us over to Coralville Lake! The first photo, taken in 1957, shows construction of the dam and spillway. The area looks much different today as the reservoir has filled in to help with flood control in the area.Coralville is one of three lakes/reservoirs in the District that help with flood control, in addition to two "dry" reservoirs we have as well!
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The emergency spillway is a parking lot for the boat ramp and beach when the lake is at its normal level.
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| Street View, Oct 2015 |
The spillway waters flow over some very old rocks.
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| Street View, Oct 2015 |
They are from the Devonian Period.
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| uiowa, p2 This bedrock was exposed by the floods in 1993 and 2008. "The limestone rocks exposed at the Devonian Fossil Gorge are of middle Devonian age (about 375 million years old) and include the Rapid and Solon members of the Little Cedar Formation. During this time, Iowa and much of North America lay at tropical latitudes just south of the equator, and the Devonian sea covered most of what is now the United States." |
The record 2008 flood:
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| By United States Army Corps of Engineers - Photo, Public Domain, Link "View of Coralville Dam at floodstage, Sunday June 15, 2008. The spillway fully open with water about 5 feet deep -- the record for the dam" |
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