Transcript Drought - Texas Climate Adaptation

Climate change related to
floods, droughts, and water
supply shortages in the
Capital Area
Raymond Slade, Jr.
Certified Professional Hydrologist
Slide show organization
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Introduction
Floods in the Capital Area
Current and previous droughts
Current and future water supply
shortages during severe drought
Do we understand water resources ?
Introduction
“The scientific literature and the Intergovernmental
Panel on Climate Change (IPCC) have
independently suggested that the intensity and
frequency of extreme weather events will increase
due to climate change.”
American Meteorological Society
It is likely that the Capital Area will experience higher and
more frequent floods, and droughts with greater intensity
and duration.
Arguably, Central Texas, has the greatest variability in
precipitation and runoff
(extreme floods and severe droughts).
Floods in the Capital Area
Google “Texas flood”…
You might get
Stevie Ray Vaughn
playing the song
“Texas flood”
Texas leads the Nation in flood
fatalities and flood damage costs
Flood fatalities by State
1959-2005
Flood insurance damage costs
by State 1978-2001
http://floodsafety.com/media/ffa/movieplayer.htm/trailer.htm
Hallettsville, Fayette County
22.7 inches of rain, June 29-30, 1940
Also in Fayette
County:
14.9 inches of rain
May 22-28, 1936
13.2 inches of rain
Oct. 30-31, 1981
San Marcos, Hays County
30 inches of rain, Oct 17-18, 1998
Also in Hays county:
15 inches of rain
May 24-31, 1929
18 inches of rain
May 14-15, 1970
16 inches of rain in 4 hours
and 12 inches in one hour
May 11-12, 1972
Pedernales River near Johnson City, Blanco County
26 inches of rain on Sept 9-11, 1952
Hwy 281
Taylor, Williamson County
38 inches of rain, Sept 10, 1921
Sept 9-10, 1921 storm and flood
• 38.2 in. during 24 hrs at a U.S. Weather
Bureau station at Thrall, Tx (national record)
• 215 drownings statewide--deadliest flood in
Texas history.
• 87 people drowned in and near Taylor and
93 in Williamson County.
Colorado River at Austin, 1935
Floods in 1936 and 1938
also topped Congress
Avenue bridge
“Floods are merely a hazard…
mankind is the disaster”
Gilbert White
Austin, Texas, 1981 Memorial Day flood
13 people drowned, $36 million damages
8 inches rainfall in 2 hours—largest rain depths fell outside Austin.
At the time of this flood, at least 7,000 families were known to live
within 100-year flood plains in Austin—most did not know.
Flooded area
in blue
Shoal Creek near
12th Street
Press release after flood
Flooded area superimposed on aerial
photo of part of Shoal Creek basin
Current and previous droughts
Google “drought”…
You might get a TV meteorologist defining
drought as an annual rainfall deficit
Father Guido Sarducci
Vatican Weatherman, SNL
Typical drought cycle
Palmer Drought Severity Index
Edwards Plateau
Through Sept. 2013
Green—wetter than
normal
Gold – drier than
normal
Increasing numbers represent greater drought intensity
Historical drought severity documentation
Severe droughts
Public water supply
systems under water
use restrictions
In 10-county Capital Area (Sept 11, 2013)
145 systems under restrictions
These systems serve 1,684,000 people
Reality—how we deal with drought
Start here
Drought Impacts
Economic Development
Agricultural Production
Electric Power Generation
Increased Wildfire Threat
Ecological Integrity
Public Water Supply
From Maidment
Current and future water supply
shortages during severe drought
Texas Water Plan 2012
Texas Water Development Board
Purpose of Plan
Estimate current and future water needs
(shortages) and identify water
management strategies and associated
costs to meet future needs.
Based on
• Data and analyses of current and future
population, water use, and water
availability (every 10 years from 2010 to
2060)
• Severe drought conditions (water demand
at maximum and supply at minimum)
• 6 water use types: i.e., municipal (urban &
rural), irrigation, livestock, manufacturing,
mining, and steam electric)
http://www.twdb.state.tx.us/wrpi/swp/swp.asp
Definitions of water category terms in the
Texas Water Plan
Existing water supplies - the amount of water that can be produced
with current permits, current contracts, and existing infrastructure
during severe drought.
Water Demand Projections - Quantity of water projected to meet the
overall necessities of an area in a specific future year.
Water supply needs (shortage) - projected water demands in excess of
existing supplies that would be legally and physically available during
a severe record.
Water management strategies - projects and associated amount of
water designed to meet needs for additional water supplies during
drought.
Capital Area population projections
Year
2010
2020
2030
2040
2050
2060
Population
1,830,000
2,322,000
2,799,000
3,303,000
3,809,000
4,277,000
2012 Texas Water Plan
Texas Water Development Board
Capital Area municipal water demand, supply, and needs
Demand minus Supply = Need
Need
Demand
Supply
Need (shortage)
Storage of Lake Austin
Municipal (urban and rural) water needs, 2020
Explanation
Burnet
985
27%
3
Llano
1681
80%
3
Williamson
16,795
52%
4
Need - acre feet per year
Percent that demand
exceeds supply
Number of water suppliers
with needs
Lee
Blanco
Total need is
1.8 times the
storage in
Lake Austin
0
0%
0
Travis
Hays
5436
52%
12
Total for area:
Need 37,011 ac-ft per year
Demand exceeds supply by 65%
43 water suppliers with needs
11,053
181%
12
Bastrop
604
36%
1
Caldwell
409
57%
7
48
11%
1
Fayette
0
0%
0
Municipal (urban and rural) water needs, 2060
Explanation
Burnet
Llano
7279
83%
7
2744
57%
4
Williamson
76,638
209%
5
Need - acre feet per year
Percent that demand
exceeds supply
Number of water suppliers
with needs
Lee
Blanco
Total need is
10 times the
storage in
Lake Austin
64
37%
1
Hays
Travis
69,352
25%
18
35,513
118%
19
Total for area:
Need 223,433 ac-ft per year
Demand exceeds supply by 65%
66 water suppliers with needs
Caldwell
2345
128%
9
Bastrop
179
40%
1
13,039
128%
2
Fayette
0
0%
0
Conclusion
“The scientific literature and the Intergovernmental
Panel on Climate Change (IPCC) have
independently suggested that the intensity and
frequency of extreme weather events will increase
due to climate change.”
American Meteorological Society
Arguably, Texas, especially central Texas, already has the greatest
variability in precipitation and runoff
(extreme floods and severe droughts).
Therefore, climate change may increase the frequency
and severity of catastrophic floods, and
the intensity and duration of severe droughts.