The document summarizes drought conditions in Texas from 2010-2011 based on a presentation by Jeffrey Lindner of the Harris County Flood Control District. It notes that 2010-2011 was the driest period on record for many locations in Texas. Wildfires destroyed thousands of structures in 2011. Lake and reservoir levels were far below average. The drought ranks as the 2nd worst in Texas history and caused billions in economic losses. Rainfall deficits remain high and it may take 25-35 inches of rain to end the drought conditions. Forecasts suggest La Nina conditions may persist, which could prolong the drought.

1. Jeffrey Lindner Meteorologist Harris County Flood Control District October 25, 2011 2010-2011 Drought

2. Texas Annual Rainfall

3. Notice Any Trends?

5. 2010 Texas Rainfall

6. 2010 Texas Rainfall Departures DRY WET

7. 2010-2011 Texas Rainfall Departures (Sept 10- Oct 11)

8. 2011 Drought Conditions

10. 2011 Drought Conditions Lake Levels and Capacity Oct 21 Lake Conroe: -6.86 (71%) Lake Houston: -5.60 (74%) Lake Livingston: -4.00 (83%) Lake Somerville: -10.03 (39%) Lake Texana: -11.59 (44%) Lake Buchanan: -28.45 (41%) Lake Travis: -52.86 (36%) Lake Georgetown: -25.36 (34%) Toledo Bend: -11.90 (59%) Sam Rayburn: -13.14 (56%) Lake Houston Lake Travis Lake Travis

11. Conservation Storage Statistics -TWDB <>

12. 2011 Drought Conditions March 30 October 19 Mandatory: 636 Voluntary: 311 Mandatory: 33 Voluntary: 34

14. Texas Wildfires – Labor Day Weekend Bastrop Complex: 34,036 acres 2 fatalities 1554 homes lost 5,000 evacuated 1351 ground personnel, 14 aircraft Tri-County: 18,638 acres 63 homes lost (23 damaged) 8,000 evacuated 698 ground personnel, 16 aircraft 20.8 million acre feet of timber burned (12.8 million in value) 12 large fires, Labor Day 2011 Over 2,000 homes lost in 3-4 days

15. Texas Burn Ban Map 229 out of 254 counties under burn bans, old record was 221 in 2006

17. October 9, 2011 Rainfall Location Rainfall: 1-1-11 to 10-8-11 Rainfall 10-9-11 New Yearly Total % 2011 Yearly Total on 10-9-11 940: Lt Vince Bayou at Jackson 9.24 6.92 16.16 43% 920: Vince Bayou at W Ellaine 10.52 6.88 17.40 40% 320: Berry Bayou at Forest Oaks 11.44 6.36 17.80 36% 310: Berry Bayou at Nevada 11.56 5.84 17.40 34% 240: Armand Bayou at Beltway 8 9.52 5.00 14.52 34% 610: Taylor Bayou at Shoreacres 12.16 5.80 17.96 32% 620: Lt Cedar Bayou at 8 th St 12.0 5.64 17.64 32% 640: HCFCD F101 at Sens Rd 10.8 4.52 15.32 30% 230: Big Island at Fairmont 13.0 4.28 17.28 25% 270: Willow/Springs at Fairmont 11.72 4.64 16.36 28% 125: Chigger Creek at Windsong 11.32 4.88 16.20 30% 1070: Spring Creek at SH 249 10.84 3.20 14.04 23% 550: White Oak at Lakeview 11.32 4.44 15.76 28% 2210: Buffalo at Turning Basin 13.0 5.68 18.68 30%

18. 2010-2011 Drought Top 5 Driest Feb-Oct 24 Periods for Houston: 2011 – 10.23 in (22.6% of normal) 1917 – 14.25 in 1930 - 15.89 in 1956 – 15.95 in 1925 – 16.69 in Top 5 Driest Jan 1-Oct 24 Periods for Houston: 1917-15.28 in 2011-15.27 in 1988- 20.71 in 1948 – 21.94 in 1901 – 22.21 in 1.1950-1957 (Sept 1956 peak) 2. 2010-? 3. 1916-1918 (Aug 1918 peak) 4. 1924-1925 (July 1925 peak) 5. 1999-2000 (Sept 2000 peak Texas Drought Rankings 4.02 inches of rain required at IAH to move to second place and .76 inches at Hobby (5.11 fell at Hobby on Oct 9…still in first place) Drought Lowest PDSI 2010-2011 -7.97 AUG 2011 1951-1957 -7.80 SEP 1956 1916-1918 -7.09 AUG 1918 1924-1925 -6.10 JUL 1925 1999-2000 -5.51 SEP 2000

19. 2010-2011 Drought Driest 12-Month Period Ever (September 30, 2010 to October 1, 2011) Red: broke previous record by over 10 inches Orange: broke previous record by over 5 inches Location Rainfall (in) (9-22-10 to 9-23-11) Previous Rainfall Record (in) Record Exceedance (in) Bellville 12.75 19.90 (1987-88) 7.15 Brenham 16.10 13.76 (1924-25) 2.34 Columbus 14.84 17.57 (1955-56) 2.73 Conroe 17.42 22.51 (1924-25) 5.09 Freeport 17.98 24.77 (1953-54) 6.79 BUSH IAH 17.71 23.25 (1916-17) 5.54 Huntsville 15.31 18.09 (1916-17) 2.78 Katy 14.67 27.31 (1987-88) 12.64 Livingston 17.77 31.35 (1947-48) 13.58 Somerville 14.83 19.77 (1970-71) 4.94 Tomball 12.44 22.15 (1960-61) 9.71 Wash on the Brazos 14.52 24.44 (1955-56) 9.92

20. 2010-2011 Drought Bellville: -29.09 Brenham: -29.70 College Station: -27.10 Columbus: -29.05 Conroe: -33.00 Freeport: -33.00 Hobby: -29.89 IAH: -30.94 Katy: -27.44 Livingston: -34.88 Matagorda: -29.93 Huntsville: -33.59 Victoria: -28.51 Tomball: -38.43 Rainfall Deficits (Oct 1 2010 to Oct 24 2011) Galveston: -43.07 Houston IAH: -31.09 Houston Hobby: -35.06 College Station: -31.10 Richmond: -38.51 Bay City: -36.74 Wharton: -34.46 Livingston: -43.28 Rainfall Deficits since Hurricane Ike Have been in mild drought since Ike, but the last 8 months have been brutal October 2010 to September 2011: Driest 1-year period ever for state of TX

21. 2010-2011 Drought 2011 Driest water year on record for Texas

23. 2010-2011 Drought Most areas would require 25-35 inches of rainfall to bring them to near normal conditions and end the drought

24. 2011-2013 ENSO Forecast Models La Nina El Nino Neutral

25. La Nina Impacts

26. La Nina Impacts

27. 2011 Drought Forecast

28. Rainfall Forecast 8-14 days 1 month 3 months

29. Questions