Examining the relationship between development patterns and total phosphorus in the Galveston Bay Estuary

Understanding how the pattern of urban development affects the nutrients level in streams and rivers is particularly important for planners and policymakers working to maximize stream and river water quality. This study focuses on the Galveston Bay Estuary in Texas, where rapid population growth and development are increasing the nutrient loads in nearby water bodies. Specifically, this study examines multiple development metrics of both high and low intensity development across 99 watersheds adjacent to the estuary and how these development metrics relate to total phosphorus as an indicator of water quality. Spatial lag models were used to determine the statistical impacts of high intensity and low intensity development on total phosphorus levels. Results indicate that less fragmented, more connected, patches of urban development (specifically low intensity development) lead to lower total phosphorus levels. In addition, as the proportion of low intensity development increases within a watershed, total phosphorus levels are increased potentially due to runoff from fertilizer. The findings from this study can provide guidance to local planning and policy makers on how to effectively reduce the amount of and potential adverse impacts of total phosphorus entering Galveston Bay.