The city of Houston, aided by HARC, is not alone among major cities in exploring ways to adapt to the risks posed by a changing climate and build a more resilient future.
Analysis of the Hurricane Ike Storm Surge and Waves
The purpose of this project was to conduct data collection, analysis and modeling for a study of the storm surge and wave impacts on land in Harris County around Galveston Bay due to Hurricane Ike in 2008 and effective ways to use breakwater islands to mitigate the effects. Analyzing the impact of Hurricane Ike represented an opportunity to isolate the effects of storm surge and wave action and develop policy options related to creation of systems for enhancement of coastal resilience.
The wind and water impacts of Hurricane Ike had a substantial effect on people, structures, and natural resources around Galveston Bay. Storm surge typically causes flooding damage in the properties due to rising water at a relatively slow rate of 0.5 to 2 feet per hour; so it is not the main reason for the large scale destruction of structures on the coast. However, storm surge enables higher waves, which in turn cause high impact and sudden damage to structures.
The Harris County Housing Authority conducted a survey, which concluded that Ike damaged more than 50% of the homes in the county. The hurricane left more than 18,000 residential units uninhabitable. The monetary loss for residential property in the county was estimated at $8.2 billion. About one third of the total cost of damage was caused by surge and waves. Harris County has more than 55% of its land classified as developed. The extent and cost of this natural disaster could provide justification for creation of engineered or natural systems that reduce storm surge and wave damage.
HARC developed this project to coordinate data collection, analysis, and strategy evaluation aimed at developing recommendations that would promote creation of effective systems to reduce damage from storm surge and wave action of hurricanes. Specifically, the effect of creating offshore breakwater islands to reduce some of the destructive force of the waves was investigated. These islands were not intended to eliminate the rising water from the surge, but to absorb the energy of the waves by forcing the waves to break offshore and then have to regenerate in a shorter distance between the breakwater island and the shoreline. The idea is that with the breakwaters closer to the shore the waves don’t have time to fully develop on the landward side. The proposed islands would be a natural area/wildlife habitat, which would have sand and vegetation on the top and a more robust structure at the bottom to stand against the force of hurricane waves and surge.