Evaluating stream health across watersheds with varying degrees of development using physical, chemical, and biological indicators

Anthropogenic stressors associated with watershed development affect stream health conditions. Prior research has shown that stream water quality based on physical, chemical, and biological indicators is different for streams under developed and non-developed settings. However, the role of each of those indicators on stream health within watersheds having different degrees and types of development has not been studied sufficiently. Therefore, this research investigates how the physical, chemical, and biological indicators capture stream health as a function of development. This investigation leverages four years (2018-2021) of monitoring data from five in-stream sampling sites with varying degrees of watershed development in four small streams in southeastern Pennsylvania: Chrome Run, Dicks Run, Rocky Run, and Dismal Run. One sampling site was studied for each stream, except Chrome Run which has two sampling sites: one at the headwaters drained by the most developed catchment area, while the second location is approximately 1,000 m downstream. This comprehensive dataset allows for the statistical analysis of stream health indicators. This includes several physical and chemical indicators (pH, total suspended solids, conductivity, chloride, total nitrogen, total Kjeldahl nitrogen, nitrate, nitrite, ammonia, total phosphorus, and phosphate) evaluated for samples obtained during baseflow and stormflow conditions. Biological indicators based on surveyed fish assemblages and benthic macroinvertebrate (e.g., index of biological integrity for northern mid-Atlantic slope, total taxa richness, Hilsenhoff biotic index) were also analyzed. Results from this study provide scientific insight that will enable watershed planners, river managers, and engineers to associate stream health with the development signature.