Galveston Bay is an area in the Upper Texas Coast (USA) historically suffering from the impact of several large magnitude hurricanes. In 2008 hurricane Ike, one of the most devastating natural disasters in Unites States recent past, raised awareness of the flood vulnerability problem of the area and triggered the beginning of different proposals, studies and designs to tackle this issue. The main action plan to be taken in the future consists on the construction of a series of interconnected dikes and storm surge barriers along the barrier islands, called Coastal Spine or Ike Dike. In this thesis, an alternative to the dike as land barrier is proposed, designed and evaluated. The concept consists of using a dune system that can serve as a flood defence structure in case of hurricane while being integrated into the coastal system in daily conditions. The dune is firstly parametrized, later its performance during design storm scenario is evaluated via numerical modelling, and lastly it is compared to the default Coastal Spine dike proposal to assess its feasibility and obtain final conclusions.