Galveston Bay Hurricane Surge Study. Report I. Effects of Proposed Barriers on Hurricane Surge Heights; Hydraulic Model Investigation

Design of barriers for protection of all or portions of Galveston Bay against inundation by hurricane surges required the use of hydraulic model studies of the Galveston Bay complex to verify the results of surge routings by analytical methods and to determine the effects of all proposed structures on normal tides and hurricane surge heights upstream and downstream from barrier sites. The Galveston Bay hurricane surge model reproduced the coast from Freeport on the south to High Island on Bolivar Peninsula on the east. The model included an average width of the Gulf of Mexico of about 25 miles, measured normal to the gulf; all of the barrier islands in the bay interior, including its many connecting arms, lakes, and lagoons; and the coastal area within this sector up to a maximum elevation of 20 ft msl; and reproduced normal tides as well as gulf surges created by hurricane forces. The model was of the fixed-bed type molded of concrete to linear scale ratios, model to prototype, of 1:100 vertically and 1:300 horizontally. Automatic tide generators reproduced normal tides and tidal currents throughout the model. Hurricane surges were reproduced by a horizontal-displacement type surge generator. Either of the two major hurricane protection plans tested would provide protection for the area inland from the barrier when the navigation openings were closed. (Author)