Coastal Development and Hurricane Risks

Overview

• Focus on present-day coastal development after covering basics of hurricane formation, categories, characteristics, and historical context
• Discussed specific examples, impacts of hurricanes, protective measures, and future directions

Coastal Protection Measures

• Seawall on Elvaston Island: In place since early 1900s
• Beach Restoration: Managed by the Galveston Park Board and the Army Corps of Engineers
• Beach Erosion: Natural processes erode beaches, necessitating replenishment
• Current Development: Continued development including Pleasure Pier and other tourist areas
• Tourism & Private Ownership: Varying levels of protection and development outside the seawall

Physical Characteristics

• Wind Currents: Dominant wind directions influence water color due to sediment transport
• Easterly/Northeast Winds: Often carry sediment from Louisiana coast, Mississippi River
• Occasional Reversal: Brings clear, blue water from the south

Hurricane Risks and Adaptations

• Unprotected Areas: Areas beyond seawall still vulnerable to hurricanes
• Raised Homes: Newer homes raised higher to mitigate storm surge damage
• Storm Surge Understanding: Increased base elevation of new structures

Statistical Hurricane Risk

• Probability Assessments:
  • 1 in 10-year event: 10% chance annually
  • Category 3 storm levees: e.g., Texas City
  • Ike almost over-topped Category 3 levee
• Different Areas, Different Risks:
  • Low risk behind seawall
  • High risk in areas like Bivard, West End
  • Flood risk from storms due to lack of protection
• Historical Data: Uses 150 years of historical data to assess risk
  • Houston/Galveston: 1 in 9 chance annually of hurricane hit

Specific Historical Events

• Hurricane Ike (2008) and Harvey (2017): Both significant events, 9 years apart

Geographic Risk Distribution

• Texas & Florida: Highest risk areas for intense hurricanes
• Probability Maps: Gulf Coast and certain East Coast areas highest risk
• Hazard Risk Scores: Indicate likelihood of being impacted by hurricanes including other hazards like wildfires and floods

Case Study: Hurricane Harvey (2017)

• Path: Zigzagged due to high pressure systems; caused prolonged rain
• Impact: Excessive rainfall (>60 inches), catastrophic flooding
• Consequences: Redesign of weather service color scheme wegen massive rainfall
• Affected Areas: Widespread inundation of lands in Houston and SE Texas

Future Directions and Protective Measures

• Proposals: Ike Dike and Coastal Armoring Plan; Controversial due to high costs
• Advocacy: For building less in high-risk, unprotected areas, elevating structures, and ensuring timely evacuations

Summary

• Ongoing development in hurricane-prone areas with focus on building safer structures
• Increase in base elevation and better forecasting and evacuation protocols