The Salt Bayou Marsh is a historically fresh to brackish water marsh located in Southeast Texas. It is connected to the Sabine-Neches Waterway (and hence to the Gulf of Mexico) via a dredged canal: the Keith Lake Fish Pass. The Fish Pass serves as an important migratory pathway for larval fish species that require the shelter of the marsh to mature in safety. However, the Fish Pass is also a conduit for salinity intrusion, via tidal pumping, which degrades the wetland substrate and promotes land loss. This presentation details the results of a numerical model study that was conducted to select an effective salinity mitigation structure to be constructed in the Keith Lake Fish Pass. The selected structure was analyzed for impacts to several factors, including salinity, velocities, larval fish recruitment, and flooding. The structure was constructed in 2015, and some initial analyses of the effects of the structure are included in the discussion.