An Integrated Watershed and Receiving Water Model for Fecal Coliform Fate and Transport in Sinclair and Dyes Inlets, Puget Sound, WA

The setup, calibration, verification, and evaluation of an integrated watershed and receiving water model developed to model fecal coliform (FC) bacteria loading, fate, and transport in Sinclair and Dyes Inlets, Puget Sound, WA, is reported. The integrated model consisted of a watershed model, an empirical FC loading model, and an estuarine fate and transport model that was used to simulate FC bacteria loading from streams, stormwater outfalls, shoreline runoff locations, and treatment plant discharges to determine the impact to water quality of the inlets. Scenarios of bacteria loading from all known sources were simulated to support a total maximum daily load (TMDL) study of bacterial pollution for the inlets. Overall, the integrated watershed-receiving water model performed very well, reproducing watershed-scale FC loading, fate, and transport in the inlets with a high degree of accuracy; the stakeholder group deemed that the predictions were acceptable within the limitations identified. Prepared in collaboration with U.S. Army Engineer Research and Development Center, Vicksburg, MS; Satellite Marine Science Laboratory, Sequim, WA; San Diego State University Foundation, San Diego, CA; and Puget Sound Naval Shipyard and Intermediate Maintenance Facility, Bremerton, WA. The original document contains color images.