Water Quality Prediction Models for Storm Water Runoff in an Urban Watershed

Best Management Practices (BMPs) have been implemented by the City of Lincoln within the urban watershed of Holmes Lake in southeastern Lincoln, NE. Water quality and quantity monitoring took place in the Antelope Creek tributary within the watershed (Colonial Hills) and a control site outside the watershed (Taylor Park). Modeling produced empirical regression equations that linked transmittable and frequently obtained parameters (e.g. in-line probes, weather station, flow meters) to other lab intensive water quality parameters. Mass loads were predicted from the models and used to calculate cumulative mass yields at the two monitoring sites for the 2010 sampling season. The yields for total suspended solids at Colonial Hills were twice those of Taylor Park. But for other parameters, including soluble reactive phosphorus, total phosphorus, and E. coli, yields were two to three times larger at the Taylor Park monitoring site. The findings suggested that the BMPs in place within the Holmes Lake watershed may have contributed to the observed differences.