There are two quite different strategies for hurricane surge barriers that would provide comprehensive protection to the industries, businesses, schools, government facilities, residences and associated infrastructure near Galveston Bay. One is the coastal spine approach, the Ike Dike, modeled after the Dutch Deltaworks, which stops oceanic surge at the coast. I have described the Ike Dike and its attributes on the website http://www.tamug.edu/ikedike/ and in in many other articles and discussions. In this editorial, I describe my concerns with the other approach - to allow the oceanic surge into Galveston Bay and provide protection by stopping the surge between the Bay’s oceanic surge engorged waters and the assets being protected. The latter approach is favored by the SSPEED Center at Rice University whose leaders have proposed the construction of a large surge gate and associated barrier in the upper reaches of Galveston Bay. There are significant problems with this approach.
The original SSPEED Center’s proposal was to construct a barrier along 146 with a major ship transit gate on the Houston Ship Channel near the Hartman Bridge. The “146 Dike”, a twenty-one foot high barrier, would extend from the present Texas City barrier across the gated channel to high ground near Baytown. In addition to this mainland barrier, SSPEED also proposed a circular barrier that would surround the eastern portion of Galveston Island. SSPEED further proposed that the projects would be funded locally by the entity being provided surge protection.
Subsequently, the SPEED Center abandoned its proposal for barriers along Highway 146 and surrounding eastern Galveston Island citing local opposition. (It is worth noting that the municipalities in these areas have endorsed the coastal spine, Ike Dike, concept.) SSPEED’s present concept is to construct a gated barrier near or a little south of the Hartman Bridge. This concept, which would be placed to protect the upper reaches of the Houston Ship Channel, is referred to as the Centennial Gate – after the principal feature of the gated barrier. Ironically, as we will see in the next sections, although the SSPEED Center’s approach has downsized from a stated strategy to protect a large portion of the western portion of land near Galveston Bay to that of protecting a select area in the upper Channel, the ultimate consequence of either approach is the same – to surround Galveston Bay with barriers.
There are serious technical and strategic issues with the Centennial Gate concept that evolve from its placement high inside Galveston Bay. The technical issue is simply that this gate must be designed to handle much higher surges than any other large navigation gate in existence or proposed throughout the world. The high surges put pressures not only on the gate structure itself but also on the foundations supporting the gate. Designing a gate that can hold back very high surges is a tough problem that even if resolved will lead to an expensive solution. This technical issue is a direct result of the SSPEED Center’s strategic decision to place the gate in the upper reaches of the Ship Channel, an area with very high surge because of the surge channeling effects of the narrowing upper Bay. Conversely, the coastal spine approach places the water barrier at the entrance to Galveston Bay where the surge is the smallest.
There are a host of other strategic shortcomings associated with the Centennial Gate’s placement high in the Bay. Perhaps the central problem with the approach is that it takes the region to a flawed coastal surge suppression strategy, a strategy that the Dutch abandoned after their major flooding disaster in 1953. After that disaster, which killed over 1800 citizens, the Dutch formed a Delta Commission to consider the appropriate strategies to protect their homeland against coastal surges. The Commission considered two main options, to continue to protect individual communities and areas by strengthening polders (circling dikes) or to protect everyone by shortening the length of the barrier needed with a coastal spine. They adopted the latter strategy and it has led to successful comprehensive protection from coastal surges for the past quarter century. Among the arguments against having individual polders strengthened is that the approach leads to ever increasing wall heights as each community tries to avoid flooding by building higher but by doing so puts its neighboring communities at greater risk so in turn they are encouraged to build higher and so on.
As with the Dutch, our choice is clear. We can choose a coastal spine that would provide protection for everyone or chose individual barriers that protect some at the expense of others. Without an Ike Dike, there are going to be huge surges in In Galveston Bay, especially in the Bay’s upper reaches. Building large barriers there might prevent surge behind them but will cause surge to increase elsewhere. Why achieve protection by putting your neighbors at increased risk if it isn’t necessary? This is exactly what the Centennial gate concept does and the consequences are enormous.
Because communities and businesses harmed by the strategy of placing the gate near them will properly want and need surge protection, the Gate is merely the first step in an approach that will lead to armoring the Bay’s shores and therefore its cost is merely the down payment in a very expensive approach to achieving comprehensive protection. Let’s explore where building the Centennial Gate will eventually lead us.
The Centennial gate concept places a major surge barrier somewhere near the Hartman Bridge. The communities and industries above the barrier would have protection but those below, especially those immediately below, would be subject to larger surges. SSPEED mentions that, if the Centennial Gate had been in place during Hurricane Ike, the increase in surge below the gates would only be measured in inches. This may be true, because Ike hit to the east and the Gate region was in an area of outflowing winds and currents, but it’s misleading because a hurricane with a path slightly farther west would cause devastating increases in surge near the gate. Besides why tolerate any increase in surge?
Not surprisingly, many people and communities below the Centennial gate are worried and upset because of its planned location. Some municipalities have passed resolutions opposing it and questioning its strategy. The City of La Porte says it very well indeed in its resolution which states, “… the City of La Porte does not accept the notion that areas of lower elevation seaward of Centennial Gate within any community fronting Galveston Bay should be considered collateral damage from the impacts of a storm surge.”
It is clear that should the Gate be built, the communities seaward of the Gate, which are now at risk of increased surges, will, quite reasonably, want increased protection. So they will build protective barriers finding the funds necessary by passing bonds or perhaps suing the owners/operators of the Gate. After these barriers are in place, the communities on the Bay just seaward of the newly constructed barriers are now at increased risk; and so it goes, with successive communities armoring against surge because they are now at greater risk because of their neighboring communities’ actions. Soon the upper Bay’s shores will be mostly covered with barriers, making it a perfect reflective surface and an ideal shape to focus incoming surge to even higher levels than we would have today, so the original gate and barriers will need to be built even higher to achieve the same level of protection; thus creating the self-defeating race for increased barrier height that the Dutch so wisely avoided.
When comparing costs, we should compare the total costs to achieve comprehensive protection not the cost of a single component, the Centennial Gate, in a circling the Bay comprehensive solution to the total costs of a coastal spine comprehensive solution. So the principal argument for building the Gate, that the Ike Dike is expensive at $4B to $6B compared to the Centennial Gate at $2B, is balderdash. The eventual total costs of an internal to the Bay surge protection strategy depend strongly on the total shore length of protection needed. The coastal spine occupies the shortest distance possible for comprehensive protection. To protect fully the Bay’s shores would require a barrier system about 3 times as long as the coastal spine. Ultimately, which surge protection strategy would be the more expensive?
The amount of federal participation in the project obviously has a strong effect on local costs needed. SSPEED envisions the Centennial Gate would need no federal funding and all funding would be contributed from local sources. I suspect that because of its damaging effects on neighboring communities that the Centennial Gate approach would have problems securing federal support. Also, acquiring local funds will be problematic. The Gate placement will cause local funding issues with municipalities having to deal with raising monies with increased taxes or bonded indebtedness for a barrier that protects some constituents but harms others.
On the other hand, I believe that a barrier founded on the Ike Dike concept would be eligible for federal funding. Work is underway to precisely determine the benefit/cost ratio but rough comparisons to the Greater New Orleans Storm Surge Barrier show that the Ike Dike would protect a much larger population and economy at much less cost and therefore have a higher benefit to cost ratio than the New Orleans Barrier. The federal government contributed all of the construction cost, almost $15B, of the New Orleans Barrier and should be expected to contribute the majority of the Ike Dike estimated costs of $4B to $6B to protect a region of much greater national strategic importance.
Recently FEMA accredited the Greater New Orleans Barrier to withhold the surges from a 100 year storm. This action essentially takes everything behind the New Orleans barrier out of the surge zone so it removes the insurance costs associated with salt water flooding. The flood maps and therefore insurance rates will still reflect whatever freshwater flooding risk the property has. Should the Ike Dike be constructed and accredited, it would greatly reduce insurance rates for almost all of us who pay flood insurance. However, the SSPEED approach even if accredited would not only severely limit the areas around Galveston Bay that are eligible for reduced flood insurance premiums but it would also cause increased flooding outside of the Gate which would in turn cause those flood insurance rates to increase.
Another major issue associated with the Centennial Gate’s position is that it is simply bad public policy to protect some at a cost to others. Why contribute to an increased risk of death and destruction in any municipality, if it can be avoided. Also, this public policy causes long recovery times. For example, without comprehensive protection, we won’t see the rapid recovery that New Orleans w experienced after Hurricane Isaac when the Greater New Orleans Barrier stopped all surge and prevented an estimated $5B in surge damages. The proposed Centennial Gate placement might protect some businesses from surge but not from long-term shutdowns because essential supporting infrastructure located seaward of the Gate is left unprotected and placed at greater risk. The protected industries’ critical suppliers or maritime support, including a passable Houston Ship Channel, may be down for months after a major hurricane. The Centennial Gate protects the upper portion of the Houston ship channel but not the majority of the channel which lies seaward of the Gate and services considerable petrochemical and maritime infrastructure, including the Port of Houston Authority’s largest container terminal. The spills and debris from these significant unprotected assets as well as from homes, small businesses, recreational and fishing craft, etc. could shut down the lower channel for months as well as cause considerable environmental damage.
Protecting some at the expense of others also raises significant social justice issues. Like all disasters, after a hurricane, the poor and the elderly are the most affected because they are the least resilient. The SSPEED approach of protection only for local entities that are able to pay for it would exacerbate the problem because richer communities would be protected but poorer communities would not only be left out but also subject to higher surges.
We are fortunate that with a coastal spine approach, we don’t have to make the devil’s choice of who is behind barriers and who is in front - between the barrier and the surge. Ultimately, the approach favored by the SSPEED center leads to and a more expensive, less comprehensive solution than the Ike Dike, coastal barrier, approach and is fraught with serious economic, social and environmental issues.