Christopher Sallese, project manager for the Gulf Coast Community Protection and Recovery District, addressed the Houston Northwest Chamber of Commerce's government affairs forum Wednesday morning to update attendees on progress with the program's study of how to mitigate future storm surge-related flood damage along the coast.
GCCPRD is in the fourth phase of a study that is examining the economic impact of storm surge on six Gulf Coast counties as well as the cost of measures that could be employed to reduce damage from future events.
GCCPRD predicts the study area—which includes the counties of Jefferson, Orange, Harris, Brazoria, Chambers and Galveston—will require $11.6 billion for measures such as installing levees and retaining walls to enhance current protection; raising the sea wall; and installing gates and other flood mitigation measures.
The plan has been described as a coastal spine—dubbed the "Ike Dike" by Texas A&M University, Sallese said, because it was conceived shortly after Hurricane Ike devastated the coast in 2008.
GCCPRD works closely with the Army Corps of Engineers to share data as the Corps works on its own study of the region, he said.
The GCCPRD study analyzes the sea level rise expected in 2035 and 2085 as well as storm and wave modeling for the upcoming decades. It also undertakes a structural component analysis of levees, T-walls—which are retaining walls—and gates; examines drainage and pumping needs; conducts navigation gate modeling in the Houston Ship Channel; and conducts an economic analysis to determine the benefit-to-cost ratio of various plans.
The sea level is estimated to rise 0.9 feet by 2035 and 2.4 feet by 2085, according to GCCPPD modeling based on historic gauge data.
The study determined that without taking flood mitigation action, a 100-year storm event in 2085 could result in a storm surge sea level rise of 19-20 feet. However, if the recommended improvements are made, Sallese said that surge could be reduced to 9-10 feet. As most docks in the Houston Ship Channel are elevated at around the 15-17 foot level, this would keep the surge out of petrochemical plants and docks, he said.
The method of funding a storm surge protection project has yet to be determined, Sallese said. Federal funds could be one source. Bonding would be challenging because the project covers so many counties and would take a long time to complete, he said.
"[GCCPRD] does not have taxing or bonding capability," Sallese said. "It needs to be looked at as a regional study."