Page 1: Rationale for Storm Barrier

Page 2: A Storm Barrier a Good Investment

Page 3: An Alternative Strategy: Galveston Bay Park Plan

An Alternative Strategy: Galveston Bay Park Plan

An alternative to the Coastal Spine is the Galveston Bay Park Plan (GBPP) proposed by Jim Blackburn co-director, Severe Storm Prediction, Education, & Evacuation from Disasters (SSPEED) Center at Rice University and the author of the 2019 report: Houston-Area Surge Flooding and its Effect on Regional and National Security.

In the report, Blackburn argues that the Coastal Spine proposal is very expensive and may not adequately protect Galveston Bay from the storm surge from rising sea levels and devastating storms such as the 2008 Hurricane Ike. Instead, Blackburn proposes GBPP utilizing a protections system including dredge materials to build wetlands and park lands within Galveston Bay that would cost between $3- $6 billion. He argues that the Coastal Spine would not sufficiently protect Galveston Bay from a storm surge that had a 15% greater wind speed than Hurricane Ike: “The spine system does reduce water levels in Galveston Bay, but sufficient water remains in the bay to cause substantial flooding along the western shoreline and in both the Bayport and Houston Ship Channel industrial complexes, where the water would rise to about 20 feet and flood many critical facilities.”

Blackburn argues his less ambitious protection system can also be constructed faster than the Coastal Spine. He states that GBPP would not block the tidal flow between the Gulf of Mexico and Galveston Bay as the Coastal Spine and would thus minimize the impact on the marine ecology in Galveston Bay: “The key to the GBPP is that the protection is proposed within the bay system to address surge from the Gulf as well as surge generated solely within the bay. This plan is compatible with navigation, and it essentially provides disposal capacity for the dredge material generated by widening the Houston Ship Channel, a current priority for oil exporters. These dredged material disposal areas could then be converted into either wetlands or park lands. Currently, the Port of Houston is seeking federal approval to widen the Houston Ship Channel, an action that would provide the construction material for the GBPP barrier wall. Thus, there may be cost sharing opportunities here.”

Blackburn argues that the GBPP will also provide protections for the populated areas of Houston and Galveston and protect Houston Ship Channel facilities including oil and gas facilities: “The GBPP provides significant protection to the populated western side of Harris and Galveston Counties and to the industrial complexes at Bayport and the Houston Ship Channel. It does not provide flood relief for the undeveloped lands of Galveston and Chambers County and therefore will not induce new development behind its protection. It is intended to protect the already existing infrastructure and development. Further, the back-side levee surrounding the city of Galveston can be expanded at an approximate additional cost between $500 million and $1 billion to protect the Port of Galveston and Texas A&M University at Galveston.”

Mitchell insists there is no alternate proposal to the Coastal Spine project. “There is no alternate proposal. The proposal by professors at Rice University to create protections for the Western end of Galveston Bay will not protect the whole bay and the entire population and the petrochemical complex from a storm surge. This is therefore not an alternative solution, but a partial solution for some of the people,” Mitchell explained.

The Exposure of Houston To Flooding

In their summary, Davlasheridze and Highfield noted that the storm surge barrier does not solve the problem of chronic flooding in the Houston and Galveston Bay areas: “To be clear, it is not a silver bullet to address the larger and increasingly challenging issues related to flooding in the region — there remains a substantial amount of long-term, comprehensive planning and implementation of many different flood mitigation techniques to address our larger flooding problems.”

Mitchell agrees: “There continues to be a problem of flooding in the region. There are legitimate concerns about the ability of the bayous to efficiently flow in a rain event and relieve the pressure of rainfall during a major event. For this reason, we have supported the Clear Creek Watershed project since 1961 in an effort to relieve flooding from high rainfalls and allow a natural outfall of rain. That project would have cost around $350 million dollars back then, but has been the subject of incremental increases in the U.S. Army Corps budget process and despite a recent infusion of $350 million will still not be complete.” 

An environmental group ‘Save The Buffalo Bayou’ cited the research of Texas A & M Galveston professor Sam Brody arguing that too much residential and commercial development in flood prone areas of Houston has undermined the ability of bayous to provide natural run-offs of water during heavy rainfall: “As wetlands have been lost, the amount of impervious surface in Harris County increased by 25 percent from 1996 to 2011.”  Thus, the spread of housing and concrete fails to absorb rainfall and allow the water to flow gradually into Galveston Bay. Instead, the high degree of development creates manmade hard surfaces, preventing water from being naturally absorbed. The result is more and worse flooding. The group argues that flooding will remain a serious problem until flood mitigation efforts are fully addressed. At the very least, the group argues it is vital “to remove the 140,000 homes that remain in the 100-year floodplain.”

Borrowing on the Dutch model of building inland reservoirs to reduce flooding, a graduate of the University of Texas at Austin Schools of Architecture and Liberal Arts, Dana Moore, has proposed, in her thesis ‘The Sentinel City,’ a way to relieve the flooding pressures on Houston by developing a string of new carless housing developments along existing rail lines, each containing a reservoir. Moore proposes a network, of what she calls the ‘String of Pearls’ be built around the Houston area over a period of years using the reservoirs to absorb heavy rainfall during storms. The water would be released later outside of the Galveston Bay, thus relieving Houston’s network of small rivers known as bayous including the Buffalo Bayou that flows into the Houston Ship Channel and then into Galveston Bay. The idea would be for the newer developments to replace older developments nearer the Ship Channel and allow creation of more open space and less concrete so that rain water would be absorbed into the ground and flow more gradually into the sea after storm surge has abated. The result, she argues, would reduce the flooding effect on Houston and the Houston Ship Channel:

“The String of Pearls is a chain of pro-development pods centered around detainment reservoirs to relieve the pressure on the overburdened bayou system. The String of Pearls catches and stores water during rainfall events, and releases it outside of the highly vulnerable Galveston Bay, effectively circumventing the compound flood zone of central Houston along the Ship Channel. They augment a modified version of the Ike Dike proposal, filling its gaps in scope.” 

Mitchell concedes that weather patterns are changing but is unsure whether they are caused by human activity: “We have to recognize that something is happening with our climate as we have seen a change from average rainfall events that have gone from 2-3-inch events in the past to become 5-7 inches’ events… Even more extreme was the 51 inches of rainfall that fell at one time from Hurricane Harvey in 2017. There is no way that you can defend against a 51-inch rain event. Now, I may be naïve in saying this, but while I believe that something is happening in Nature, I do not know whether it is man-made or not.”