IDENTIFYING ASSOCIATIONS BETWEEN HUMAN-ENVIRONMENTAL FACTORS AND WATER QUALITY TRENDS OBSERVED AT PERENNIAL HEADWATER STREAMS OF THE SAN BERNARDINO NATIONAL FOREST, CALIFORNIA

Anthropogenic factors related to landscape activities, infrastructure, and alterations, coupled with severe climatic fluctuations (i.e., droughts and extreme hydrological events) are increasingly impairing the quality of surface water resources across multiple geographic scales, warranting the need for comprehensive investigations of the cumulative effects of human-environmental stressors at multiple scales within a watershed. This study assessed three perennial headwater streams of the San Bernardino National Forest, California. The streams were tested for one year from October 2019 to September 2020 for conductivity, dissolved oxygen (DO), pH, turbidity, temperature, ammonium (NH4+), nitrate (NO3-), total coliform (TC), Escherichia coli (E. coli), and enterococci to establish water quality trends before entering downstream watershed features. The study also analyzed precipitation data, land cover data, and federal, state, and regional water quality objectives, standards, and recommendations (i.e., regulatory criteria). A comprehensive analysis of this data will help to establish baseline knowledge of the water quality of the three headwater perennial streams, determine the streams’ compliance with regulatory criteria, and determine whether possible associations exist between human-environmental factors (i.e., nearby land cover and seasonal fluctuations) and the observed baseline and compliance trends of the three study streams. Identifying human-environmental factors, specifically related to perennial headwater stream impairments, is crucial to the efficient management of watersheds, as these surface water features play a significant role in influencing water quality and quantity across hydrologic networks. The findings of this study can provide water resource managers and related stakeholders with the data needed to guide accurate and informed decisions when developing comprehensive and collaborative headwater management programs that align in support of maintaining high-quality surface water resources throughout hydrologic networks