1. Historic Flooding of May 7, 2009 for the City of Montgomery, Alabama

2. Torrential rain caused severe flash flooding in Montgomery and surrounding areas on May 7, The River Region experienced a line of severe thunderstorms having widespread rainfall totals of six to eight inches, with local amounts in excess of 10 inches, falling in just over a four hour time period.

3. From NOAA’s Technical Paper No
From NOAA’s Technical Paper No. 40 (SCS method) we can see that a 100-year 6-hour storm would be about a 7 inch event.

4. 6 7 8 9

5. Areas impacted by this storm event were: Autauga County
Elmore County
Montgomery County
Macon County
Bullock County

6. Storm vs. flood, what is the difference?

7. Following the May 7, 2009 flood event, the USGS collected data for the following streams:
Oliver Creek
Sherwood Ditch
Jenkins Creek (2)
Baldwin Slough (2)
Three Mile Branch
Miller Creek

8. Location of data collection sites

9. The Tools

10. Oliver Creek @ University Drive Drainage area = 2.7 sq. mi.
Computed peak flow = 4,880 cfs
Runoff per square mile = 1,781 cfsm
Published Q500 (FEMA) = 3,500 cfs (Atlanta Highway – DA = 3.7 sq. mi)

11. Sherwood Ditch @ Sherwood Drive Drainage area = 2.3 sq. mi.
Computed peak flow = 6,170 cfs
Runoff per square mile = 2,683 cfsm
Published Q500 (FEMA) = 4,987 cfs (At Mouth – DA = 2.8 sq. mi.)

12. Jenkins Creek @ Chantilly Pkwy Drainage area = 7.1 sq. mi.
Computed peak flow = 5,740 cfs
Runoff per square mile = 808 cfsm
Published Q500 (FEMA) = 5,160 cfs (At CSX RR – DA = 7.3 sq. mi.)

13. Jenkins Creek @ I 65/US 80 Drainage area = 12.3 sq. mi.
Computed peak flow = 9,700 cfs
Runoff per square mile = 789 cfsm
Published Q500 (FEMA) = 10,480 cfs

14. Baldwin Slough @ McGee Road Drainage area = 2.3 sq. mi.
Computed peak flow = 5,720 cfs
Runoff per square mile = 2,487 cfsm
Published Q500 (FEMA) = 3,430 cfs

15. Baldwin Slough @ Woodley Road Drainage area = 4.6 sq. mi.
Computed peak flow = 5,920 cfs
Runoff per square mile =1,287 cfsm
Published Q500 (FEMA) = 6,090 cfs

16. Three Mile Branch @ Federal Drive Drainage area = 8.1 sq. mi.
Computed peak flow = 8,300 cfs
Runoff per square mile =1,025 cfsm
Published Q100 (FEMA) = 8,209 cfs

17. Miller Creek @ I 65/US 80 Drainage area = 15.7 sq. mi.
Computed peak flow = 5,220 cfs
Runoff per square mile = 332 cfsm
Published Q50 (FEMA) = 6,730 cfs

18. Montgomery Runoff Curve for May 7, 2009 Flood
CFSM
Drainage Area in sq. mi.

19. September, 2009 Atlanta flood
N.F. Peachtree Creek cfsm (DA=1.42 sq. mi.)
Butler Creek – cfsm (DA=3.6 sq. mi.)
Allatoona Creek cfsm (DA=14.1 sq.mi.)
Pew Creek cfsm (DA=7.0 sq. mi.)
Powder Springs Creek cfsm (DA=17.3 sq. mi.)
Noonday Creek cfsm (DA=24.3 sq. mi.)
Sope Creek cfsm (DA=29.2 sq. mi.)

20. May, 2010 Nashville flood Locke Branch - 2222 cfsm (DA=0.81 sq. mi.)
South Garrison Creek – cfsm (DA=0.51 sq. mi.)
Slick Rock Creek cfsm (DA=0.36 sq.mi.)
White Oak Branch cfsm (DA=0.26 sq. mi.)
Kelley Creek cfsm (DA=2.18 sq. mi.)
Copperas Branch cfsm (DA=1.62 sq. mi.)
Richland Creek cfsm (DA=24.3 sq. mi.)
Browns Creek cfsm (DA=11.8 sq. mi.)

21. May, 2009 Montgomery flood Sherwood Ditch - 2683 cfsm (DA=2.3 sq. mi.)
Baldwin Slough – cfsm (DA=2.3 sq. mi.)
Oliver Creek cfsm (DA=2.7 sq.mi.)
Baldwin Slough cfsm (DA=4.6 sq. mi.)
Three Mile Branch cfsm (DA=8.1 sq. mi.)
Jenkins Creek cfsm (DA=7.1 sq. mi.)
Jenkins Creek cfsm (DA=12.3 sq. mi.)
Miller Creek cfsm (DA=15.7 sq. mi.)

22. The Need: More Data! New USGS gages: (Montgomery)
Sherwood Sherwood Drive
Baldwin Woodley Road
Oliver University Drive
Jenkins Chantilly Pkwy
Three Mile Federal Drive

23. Questions ???