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

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.

Unusual Damage

Unusual Damage

Unusual Damage

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. 88.6 % of the highway bridges survived the flood with NO SIGNIFICANT DAMAGE.

BridgeWatch System

Tracking the 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.

Debris Accumulation

Debris Accumulation

Debris Accumulation

Approach Roadway Damage

Approach Roadway Damage

Approach Roadway Damage

Approach Roadway Damage

Approach Roadway Damage

Embankment Erosion

Embankment Erosion

Embankment Erosion

Embankment Erosion

Bridge Scour

Bridge Scour

Bridge Scour

Structural Damage

Structural Damage

Structural Damage

Structural Damage

Structural Damage

Summary of Flood Damage 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

Summary (Continued) 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

Questions?