AbstractA continuous in-stream water quality measurement (CWQ) study was carried out in two Lincoln, Nebraska urban watersheds. Discrete stormwater samples were collected at the study sites during 17 storm runoff events over a three-year period. In-stream flow and water quality (e.g., turbidity) measurements were combined with climatic data to develop multiple-linear regression (MLR) models for the estimation of six stormwater pollutant concentrations [i.e., total suspended solids (TSS), soluble reactive phosphorus (SRP), total phosphorus (TP), nitrate plus nitrite-nitrogen (N+N), total Kjeldahl nitrogen (TKN), and Escherichia coli (E. coli)]. MLR concentration models based on in-stream measurements (CWQ-C) were developed to estimate pollutant concentrations at any time during a storm. Three additional MLR models were developed to estimate event mass loads based on (1) climatic data only, (2) both CWQ and climatic data (CWQ-L), and (3) use of literature event mean concentrations (simple mass load). The co...