Modeling bacterial load scenarios in a Texas coastal watershed to support decision-making for improving water quality

Abstract

The planning for improved health of a stream can be optimized by assessing the watershed system as a whole; state and federal agencies have embraced this watershed approach for managing water quality (USEPA 2008). Using the watershed approach, bacteria loads in the Double Bayou watershed were modeled to identify critical loading areas and develop appropriate voluntary management measures as part of a watershed protection plan. The Spatially Explicit Load Enrichment Calculation Tool (SELECT) model was developed by the Department of Biological and Agricultural Engineering and the Spatial Science Laboratory at Texas A&M University to estimate potential pollutant loadings from fecal indicator bacteria. For this study, SELECT modeling was performed to estimate bacterial loadings from the distribution of livestock, wildlife, a wastewater treatment facility, and on-site sewage facilities. Rankings of each contributing source were assessed for the entire watershed. The objective of this study was to analyze the success of using SELECT to evaluate bacteria loads in a rural coastal watershed; results showed SELECT was successful in the Double Bayou watershed in ranking categories of bacteria sources and revealing spatial load aggregations. This analysis guides discussion on the prioritization of management measures to improve water quality in the Double Bayou watershed. Citation: Glen SM, Bare RM, Neish BS. 2017. Modeling bacterial load scenarios in a Texas coastal watershed to support decision-making for improving water quality. Texas Water Journal. 8(1):57-66. Available from: https://doi.org/10.21423/twj.v8i1.7048.