As the advocates for building the coastal spine, also known as the Ike Dike, gear up to use the tragic flooding to our region by Hurricane Harvey to get the political machines working to build the project, let’s take a step back and discuss what the Ike Dike will and won’t do, and whether its enormous cost is the best investment to address the serious problem we face.
The Ike Dike has been strongly promoted by various groups since Hurricane Ike as the solution to hurricane storm surge flooding for the communities and industries along Galveston Bay. It proposes a coastal barrier of levees behind the beaches of Galveston Island’s West End and along Bolivar Peninsula. The two levees would be linked by large gates between Galveston and the peninsula that would be designed to close on the approach of a hurricane to stop surge entering Galveston Bay. The noble goal of finding a solution to the damage caused by storm surge is one we all seek, but the discussion to-date has only been on building the Ike Dike, not about whether it will do what it has been sold to do, and what consequences we will have to accept if it is built.
Keeping storm surge out of Galveston Bay will reduce the risks of flooding, but not all the risks. Closing off the bay will still leave Galveston, west bay communities and Houston Ship Channel industries vulnerable to flooding generated by hurricane force winds blowing across the bay itself. Research by Rice University’s Severe Storm Prediction, Education, and Evacuation from Disasters Center shows the critical flood protection of the industries that line the ship channel isn’t achieved by stopping the surge at the coast because the bay can generate its own surge. Unfortunately, discussion for designing local flood protection systems around the bay has been squashed by Ike Dike advocates because it diminishes the need for a structure at the coast, particularly its expensive and difficult to engineer gates at the entrance to Galveston Bay.
Galveston’s West End and Bolivar Peninsula communities would benefit significantly from a coastal seawall blocking storm surge blown in from the gulf, but they would still be vulnerable to surge coming from the bay when hurricane force winds blow from the north. Downtown Galveston experienced flooding during Harvey when winds coming from the north pushed water against the bay side of the city, restricting the outflow into the bay of 9 inches of rain that fell in the city during one day.
A ring levee has been proposed as a solution for Galveston. It would include improved handling of storm water runoff within the city that might be assisted by pumps, which are used in Texas City’s flood protection system. Such a system protecting Galveston from surge originating in the bay will still be needed if the Ike Dike is built. What hasn’t been asked is whether building a Galveston ring levee and other local protections for communities and industrial areas around the bay would be a more efficient, effective and environmentally sound approach, particularly given that they will be needed anyway.
Let’s use the attention that Hurricane Harvey brings to our vulnerability to hurricane-caused flooding to consider what options we really have, what solutions will actually address the problem each of our communities face, and what is the most cost effective way to implement them. After all, what our region experienced during Hurricane Harvey would not have been stopped by the Ike Dike.