Experiencing severe coastal storms has always been part of living near the sea; however, current planning models and infrastructures are putting residents in positions equivalent to placing their heads in the sand. On September 13, 2008 Hurricane Ike struck the upper Texas coast, wreaking havoc on infrastructure and washing away entire communities. In response, SWA teamed with the University of Houston for Rice University’s SSPEED (Severe Storm Prediction, Education and Evacuation from Natural Disasters) Center to identify a system of solutions that equally considers structural and non-structural strategies.
The focus was to protect where appropriate and promote land uses resilient to environmental forces, where the viability of the landscape is an indication of effective, sustainable shields to flooding.
Hurricane Ike still narrowly missed the modeled “worst case scenario,” where storm waters would track up the densely populated west shore of Galveston Bay and into the heavily industrialized Houston Ship Channel. Labeled only as a category two storm by wind speed, Ike surpassed all inundation damage predictions for its designation and changed the lives of millions of people.
This one event, in a region populated by 6.5 million residents and frequented by hurricanes, sparked a sorely needed reassessment of historic storm preparedness . The first major proposal was the “Ike Dike”, a continuous dike to be built across the bay. This proposal came with high costs and potential for great environmental degradation. Once completed, the monumental dike would promote a false sense of safety, exponentially increasing the original post-Ike rush to rebuild and develop and exposing millions more to future risk in the still environmentally fragile bay. Before long, the concept was deemed a “moral hazard”.
What are needed instead are new approaches to effectively and sustainably protect and develop our modern coastlines by the integration of land use and necessary infrastructures.
The Coastal Resilience project aims to identify reasonable planning solutions to respond to Galveston Bay’s frequent tropical storms, hurricanes, and coast shaping forces. Currently, there is no clear understanding of the level of risks along the coastline, and even in the presence of clear information, it is human nature to underestimate high-level risks that occur infrequently. As a starting point, suggested non-structural responses included: improving and strictly enforcing building codes, hardening public infrastructure to be protected to a 100 year surge level, removing flood and wind subsidies in unprotected areas, buyout storm damaged properties after an additional flood, full disclosure for all future purchases, flood depth signage in all unprotected areas, better communication tools like readily available storm surge maps, and alternative land uses such as the creation of a national recreation area.
Structural or levee building opportunities sought to protect highly populated and culturally significant areas such as building an earthen levee that can protect against a 500 year return frequency (including a wave protection factor) to encourage development in the protected area. The resulting plan also identified an opportunity to tie the coastal defense infrastructure into the natural topography by rebuilding an existing roadway to specifications offering the desired 100 year flood protection and creating marshes, coastal dunes and waterfront parks to help heal the bay, promote habitat development, absorb the storm surges and sustain and protect the coastline. With this approach, isolated ‘pocket’ levee systems would only be needed in areas of existing high value development like the Houston Ship Channel. The great expense of land acquisition for post-disaster buyouts would be minimized and few populated areas would be excluded from protection. This would afford some development opportunities and also promote agriculture, recreation areas, eco-tourism and carbon sequestration opportunities outside the identified zones of protection.
This project identifies several responses to this reoccurring event and plans for the health, safety and welfare of the Galveston Bay region, subject to severe environmental forces. Each measure taken would be evaluated to maximize both the economic benefits to the local community and the potential for enhancement of the environment.
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Posted by The Coastal Resilience Team in Landscape Infrastructure on