Interest in developing freshwater inflow needs or standards for Texas estuaries occurred in three eras over a 50-year period. In 1967, the concept that water is needed for preservation of bays and estuaries was first proposed. In 1975, the first law was enacted to study effects of freshwater inflow on estuaries. In the 1980s, the first detailed freshwater inflow needs studies were completed for all bays based on hydrology, salinity, and fisheries harvest. In 1994, three Texas state agencies cooperated to synthesize all the studies performed in the 1980s into one volume describing the state methodology and recommending new standards. Following major legislative changes in 2007, science and stakeholder teams were formed to recommend inflow regimes for each of the seven bay systems, and by 2014, inflow standards were adopted for all bay systems. Over time, the laws and standards evolved from a species management approach to an ecosystem-based management approach.