A Coastal Barrier Protecting the Houston/Galveston Region from Hurricane Storm Surge

Transcription

1 A Coastal Barrier Protecting the Houston/Galveston Region from Hurricane Storm Surge 1/20/2011

2 The Houston/Galveston Region Is home to about 2 Million people and may double by 2050 Galveston Bay provides valuable ecosystem services Supports largest petrochemical complex in US Port of Houston alone generates over $117 Billion in economic activity annually Houston area Industry/Economy is much more important nationally than New Orleans where $14B is being spent on surge suppression

3 Regional Threats and Vulnerabilities Affected by a major storm about every 15 years Surges are channeled up the Bay Considerable infrastructure near sea level Large-scale evacuations are increasingly difficult Especially for Hurricanes that quickly increase in intensity and/or change direction

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5 Time of forming Cat 3 to landfall- 6+ hours Within 250-miles of the landfall location hours Center for Texas Beaches & Shores, Texas A&M University at Galveston

6 Chasing Ike Sheltering Community Staging Area Evacuating Area NHC Advisories Sept Source: Dr. Gordon Wells, UTA

7 1932 hurricane image

8 September 13, 2008 Ike passed over Galveston Island Killing about 48 people Causing $30 Billion dollars in damage Plus many hidden costs Damaging sensitive ecosystems and wildlife habitats Devastating our vulnerable (poor, elderly) populations much more than others Demonstrating the region s vulnerabilities Triggering the need for surge protection

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14 Had It Hit Farther West Many more lives lost Billions more in damage Perryman Report Katrina-like storm would cause aggregate losses to Texas economy of $73B in gross product, $61.3B in income and 863,000 jobs

15 Source: Dr. Gordon Wells, UTA Possible Cat 4 Surge

16 Dutch response A similar problem The 1953 de Ramp

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18 The overall strategy is to keep the ocean surge out of Galveston Bay using a coastal barrier (the Ike Dike) similar to the Dutch Delta Works Houston Ship Channel High Island Bolivar Roads Existing Seawall Intracoastal Waterway Coastal Spine San Luis Pass

19 Houston Ship Channel High Island The first component of the Ike Dike already exists the Galveston Seawall Bolivar Roads Existing Seawall Intracoastal Waterway San Luis Pass

20 Galveston Seawall -17 foot tall fixed barrier The Galveston Seawall has done it s job preventing catastrophic Gulf overflow But does not prevent back surge from the Bay

21 Houston Ship Channel High Island The second component - Land Extensions of the protection afforded by the Seawall Bolivar Roads Existing Seawall Intracoastal Waterway San Luis Pass

22 Design by Marie Garrett, Coastal Solutions Inc and Dr. Billy Edge. Texas A&M University.

23 Revetments can be hidden to look natural

24 Protection can also be by raised highway Coastal highways could be raised 12 feet

25 Houston Ship Channel High Island The third component - Sea Barriers Bolivar Roads Existing Seawall Intracoastal Waterway San Luis Pass

26 The Galveston Gates Galveston gates will be the costliest component of the Ike Dike and its biggest tourist attraction Must not impede navigation Must allow water circulation into the bay under normal conditions But close quickly when a hurricane approaches to provide a 17ft higher-than-sea-level barrier across Bolivar Roads Can we use existing technology?

27 A navigation solution

28 Animation of the flood gates closing

29 Closed Flood Gates

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31 Bolivar Roads

32 A Bay circulation solution

33 The Netherlands Storm Surge Barrier in Action

34 Possible New York Barrier

35 All together it forms a coastal spine But will the Ike Dike, suppress massive surges? Houston Ship Channel High Island Bolivar Roads Existing Seawall Intracoastal Waterway San Luis Pass

36 Simulations: Ike s Surge without an Ike Dike - The University of Texas Gordon Wells, Jennifer Profit, Clint Dawson

37 Simulations: Ike s Surge with an Ike Dike - The University of Texas Gordon Wells, Jennifer Profit, Clint Dawson

38 Simulations: Difference in Ike s Surge with and without an Ike Dike Gordon Wells, Jennifer Profit, Clint Dawson

39 Additional Characteristics Allows Bay shores to be natural System can be leaky - unlike New Orleans Only needs to hold maximum surge for a few hours Designed for a 10,000 yr storm Most Hurricane surges much smaller

40 Contact Information George P. Mitchell 40 Chair Department of Marine Sciences Texas A&M University at Galveston

41 Hurricane Ike Chinese FY1-D MVISR September 12, 2008 at 6:18 PM CDT

42 The Ike Dike Provides Comprehensive Protection from Storm Surge Protects People, Properties and Industrial Base for a Nationally Important Region Reduces Vulnerability Will Encourage Investment in and Commitment to the Region Costs Much Less than a Single Hurricane Recovery Probably Costs Less Than Individually Armoring the Entire Bay Complex

43 The Ike Dike (continued) Prevents Surge Damage to the Bay s Natural Resources Is More Environmentally Sound than Armoring the Entire Bay Complex Best (and Perhaps Only) Way to Protect Our Less Resilient Populations Protects Lives Especially During Difficult Evacuations from Hurricanes that Quickly Change Path or Intensity

44 Next Steps Six County Public Corporation formed Each County Judge is on the Board Will select three at-large Board members Robert Eckels appointed president Dannenbaum appointed engineering consultant Legal, Secretary/Treasurer set up Congressional Action and/or Recovery Monies Public Outreach and Involvement

45 Design Premise The human settlement near Galveston Bay has reached such a size and importance - and hurricane surge is such a significant threat - that a comprehensive regional approach to surge suppression makes sense

46 Outline What we wish to protect The nature of the threat Proposed comprehensive solution Its attributes/issues Next steps

47 Combining Gate designs, the Bolivar Roads portion of the Barrier can: - allow navigation in the Ship Channels - allow for circulation in Galveston Bay