Demonstration of the WERF Process for Deriving Site-Specific Nutrient Goals in a Wadeable Stream

The Water Environment Research Foundation and Colorado Monitoring Framework con-ducted a demonstration of the WERF Nutrient Modeling Toolbox (NMT) that was developed as part of WERF project LINK1T11. The chosen demonstration site was Boulder Creek, a wadeable stream that drains the Rocky Mountains and flows through the City of Boulder, CO. Ecological response variables of interest were dissolved oxygen, pH, bottom algae chlorophyll-a, and benthic macroinvertebrates. The project team applied the model to various exploratory scenarios of nutrient reduction in the Boulder Creek watershed. The model indicated that environmental benefits could be maximized by more phosphorus control and less nitrogen control than would be pursued under default regulations. These technical findings were used to craft a staged, adaptive nutrient management strategy for Boulder Creek. Overall, the WERF process was found to be highly beneficial for understanding the receiving water and improving management strategies.