[Jon is the TDOT Hydraulics Section, Manager, Nashville, TN] The flood of May 2010 was a record rainfall and flood event in Nashville, Tennessee and many parts of middle and west Tennessee. The maximum rainfall for the event exceeded the 1000 year 48 hour rainfall frequency of 12.2 inches in the Nashville area according to NOAA Atlas 14 by as much as 5 inches in closer to 36 hours. River stages ranged from a 200 year flood frequency elevation to as much as 4 and 5 ft above the 500 year FEMA elevations in rivers and creeks in middle Tennessee. Floods of this magnitude are expected to cause millions of dollars in damage to property and disruption to traffic, commerce, government operation and even loss of life and this flood met expectations quite well in middle and west Tennessee. This presentation will focus on the damage of several types to roads and bridges in the riverine environment and recovery efforts in the Nashville area and middle Tennessee from the TDOT perspective as well as new bridge design efforts. The presentation will also discuss the cleanup and property management issues for event recovery and preparation for future flood events from a flood plain management perspective for Metro Nashville government.

1. 2014 River Management Society Symposium
Managing Rivers in Changing Climes: Training Tomorrow’s River
Professionals
Jon Zirkle, P.E.

2. May 1-2, 2010
 On the above dates, a massive rainstorm swept through West
and Middle Tennessee. A 1000+ year rainfall event.
 The storm crossed the Mississippi River, north of Memphis,
and swept northeast through Nashville.
 Many areas received from 13 to 18 inches of rain in less than a
48 hour period.
 According to NOAA Atlas 14, the 1000 year 48 hour rainfall
event in Middle Tennessee is 11.7 inches.
 Streams and major rivers responded with flood elevations
ranging from less than a 50 year event to 4 ft above the
expected 500 year event.

3. Affected Area

4. Heavy Flooding Occurred

5. Statistics
 21 Deaths occurred in Tennessee due to the flood.
 52 of Tennessee’s 95 Counties were declared as Federal
Disaster Areas.
 Damages in Tennessee were expected to be over $2
billion dollars.
 $45M in FHWA authorized emergency repairs alone

6. Expected Damage
Landslides above
and below the road
Pavement and shoulder
damage, debris and down
power lines

7. Unusual Damage

8. Unusual Damage

9. Unusual Damage

10. What about the Highway Bridges?
 44 of the 52 Counties had bridges that suffered
maintenance issues because of the flood. The total
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.

11. 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.

12. Debris Accumulation

13. Debris Accumulation

14. Debris Accumulation

15. Debris Accumulation

16. Approach Roadway Damage

17. Approach Roadway Damage

18. Approach Roadway Damage

19. Approach Roadway Damage

20. Embankment Erosion

21. Embankment Erosion

22. Bridge Scour

23. Bridge Scour

24. Bridge Scour

25. Structural Damage

26. Structural Damage

27. Structural Damage

28. Structural Damage

29. 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

30. 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

31. Bridge Design

32. Bridge Design

33. River Training
Bendway weirs
Rock spurs

34. Questions?
Jon Zirkle, PE
C.E. Manager 1
TDOT Hydraulics Section
Suite 1200, J.K. Polk Bldg.
505 Deaderick Street
Nashville, TN 37243
Jon.zirkle@tn.gov