1000+ Year Flood Event Terry D. Leatherwood, P.E.

 On the above dates, a massive rainstorm swept through West and Middle Tennessee.  The storm crossed the Mississippi River, North of Memphis, and swept Northeast toward Nashville.  Many areas received from 15 to 20 inches of rain during a 48 hour period.

 21 Deaths occurred in Tennessee due to the flood.  52 of Tennessee’s 95 Counties were declared as Federal Disaster Areas.  Although a final tally has yet to be made, damages in Tennessee are expected to be over $2 billion dollars.

 44 of the 52 Counties had bridges that suffered maintenance issues because of the flood. The total currently stands at 1,167 structures with damage.  These 44 Counties have a total of 10,216 highway bridges over waterways.  Therefore, only 11.4 % of bridges over waterways needed maintenance % of the highway bridges survived the flood with NO SIGNIFICANT DAMAGE.

 In order to track the damage, a database table for flood damaged bridges was created.  Five categories of damage were tracked.  Bridges could have multiple types of damage.  If the bridge required closure, that was also noted.

 Our Database shows damage to 1,167 Highway Bridges  773 Bridges had a single type of damage  317 Bridges had two types of damage  65 Bridges had three types of damage  4 Bridges had four types of damage  1 Bridge has all five types of damage

 504 Bridges showed debris accumulation  415 Bridges had damage to the roadway approaches  At 362 Bridge Sites, there was channel embankment erosion  225 Bridges showed scour damage  115 Bridges suffered some type of structural damage  54 Bridges required closure