Su, Yu-Chun, Ph.D., Julie Morse, Martin Heaney, and Stanley CooperThe Sixth Biennial State of the Bay Symposium January 14-16, 20032010-02-152010-02-152003http://hdl.handle.net/1969.3/26393pg. 229The IH 45 Galveston Causeway is a major bridge connecting Galveston Island to the Texas mainland. Due to the age and condition of the bridge, the Texas Department of Transportation (TxDOT) has developed a plan to rebuild the bridge. The proposed construction included alternatives to build temporary access roads for the construction of the main bridge. These access roads would cause partial blockage of West Bay for an estimated period of four years that could result in 1) an increase in current velocity that may impact navigation; 2) a reduction in tidal flushing that may impact water quality, bay benthos, peripheral salt marshes, and other aquatic communities; and 3) an impact on salinity distribution in the area. To investigate these potential impacts, a two-dimensional (2D) hydrodynamic and water quality model was developed.... This paper will present the development and findings of this modeling effort. Conclusions of this modeling effort contributed to the change of construction method toward a more environmentally friendly approach. The paper will present the new approach and a proposed schedule to complete the construction of the Galveston Causeway Bridge.water qualityhabitatecologywatershed managementinterstategalvestoncausewayconstructionwest baybay benthossalt marshesaquatic communitiessalinity distributionhydrodynamic modelstidefreshwater flowbathymetrypoint sourcesan luis passgalveston entrance channelchocolate bayouBook