The Nose Creek Watershed Partnership (NCWP) has embarked on an ambitious project to create a detailed watershed-scale model of Nose Creek and West Nose Creek (collectively the Nose Creek Watershed). The NCWP hired Barr to develop the Nose Creek Watershed Model (NCWM) and a graphical user interface (GUI) that would allow NCWP staff to independently run the model. The goal is a detailed hydrologic, hydraulic, and water quality model of the watershed that allows the organization to better understand current watershed conditions, predict future conditions based on development and growth, and weigh potential outcomes of management strategies across jurisdictions.
Barr first conducted a scoping study to identify the best models that could be applied in combination to achieve these goals. We evaluated 20 different models based on accessibility for software support, user friendliness, data requirements and availability, and output format. From these results and input from project partners, we recommended four models: SWAT, PCSWMM, EFDC, and HEC-RAS.
We began by developing a detailed model combining SWAT and PCSWMM to simulate watershed hydrology and water quality. Barr developed a SWAT model of the watershed’s rural areas, and we partnered with Kerr Wood Leidal Associates Ltd. (KWL) to develop a PCSWMM model of urban areas—encompassing four municipalities. The combined models are designed to run continuously to simulate long-term watershed processes. NCWP selected a stand-alone, event-based HEC-RAS model, also built by Barr, to simulate channel and floodplain hydraulics.
This project is ongoing. Future phases of the work will include conducting SWAT and PCSWMM model calibrations and sensitivity analyses, constructing and calibrating an EFDC model of in-channel water quality processes, constructing the GUI, and applying the model to assess the current state of the watershed and evaluate future conditions and management strategies.