(WKRN) – The rainfall on August 21, 2021, was historic. Parts of west Middle Tennessee received eight to over 20 inches of rain in 24 hours, and most of that came between midnight and the mid-morning hours.

Graphic courtesy of the National Weather Service in Nashville

Although Waverly had rainfall amounts in the 8″ to close to 10″ range, nine miles to the east, McEwen received 17″ to 20″ plus. As a matter of fact, a state record for 24 hours was set at the McEwen Waste Water treatment when 20.73 inches was measured.

Graphic courtesy of the National Weather Service in Nashville
Graphic courtesy of the National Weather Service in Nashville

All this in itself would be enough to cause major flooding in the area. But there was something else that day that made it worse for Waverly.

Trace Creek, which caused the flooding in Waverly, runs basically from east to west from McEwen to Waverly. So whether it falls in McEwen, Waverly, or any point in between, it ends up in Trace Creek.

But during the event, a railroad bridge just east, or upstream of Waverly clogged with debris, causing the water to back up, making a lake with an estimated 47,900,000 gallons of water.

Graphic courtesy of the U.S. Army Corps of Engineers

Eventually, a breach in the railroad bed occurred, and all that water suddenly rushed downstream to Waverly.

The railroad tracks were left hanging in mid-air.

The result? This tsunami-like wall of water rushing downstream into Waverly, climbing to around four feet or higher in a matter of roughly eight to nine minutes.

Courtesy of Michael Phillips

Although with this much rain, severe flooding still would have occurred, most feel that the big rush of water into downtown Waverly would not have happened without the debris-blocked railroad bridge creating that huge lake.