Two main themes are examined in this report: 1) demonstrating the effects of freshwater inflows on living and non-living components of estuarine ecosystems and 2) presenting a methodology for assessing the freshwater inflow needs of Texas bays and estuaries that satisfies the requirement of maintaining an ecologically sound environment and the productivity of fish, shellfish, and other estuarine life. This is the final report; refer to the draft version cited as Acc# 6134.