Effects of small freshwater inflow volumes on water and sediment quality obtained from bays in Texas from 2015-09-30 to 2016-09-15

This study contains data showing effects of small freshwater inflow volumes on water and sediment quality obtained from bays in Texas, specifically Lavaca-Colorado and Guadalupe estuaries, from to 2015-09-30 to 2016-09-15. The aim of this study was to quantify the effects of small changes of inflow volumes on ecosystem health to evaluate the potential environmental benefits of hydrological conservation or restoration projects. Discharge, water quality (indicated by nutrients and chlorophyll), and sediment quality (indicated by benthic communities) were sampled monthly at five stations in the upper reaches of the Guadalupe and Lavaca-Colorado estuaries. Distinct oligohaline and mesohaline benthic communities were present in both estuaries. Flow discharge, water quality, and benthic metrics were correlated. The positive correlation between multivariate water quality parameters, and benthic metrics indicates a positive relationship between small flow changes and estuarine health. The Guadalupe estuary had a 92% higher mean monthly freshwater inflow rate than the Lavaca-Colorado estuary, thus a larger flow volume increase was necessary to affect estuarine health in the Guadalupe estuary. This analysis indicated that a small volume, as low as 10% of freshwater inflow volume, can have positive benefits to estuarine conditions and health. Thus, hydrological protection or restoration projects based on small volumes can improve estuaries degraded by freshwater diversions.