Stormwater management and stormwater planning are often conducted at the local municipal level. Methods used to estimate or model runoff and plan interventions can vary widely, and often utilize opaque or proprietary approaches which may be challenging to update. Cape Cod Commission staff will present a methodology that used state-wide publicly available GIS layers for land use, land cover, and soil type to determine Hydrologic Response Units (HRUs) for all of Barnstable County. Case studies will be presented to show the utility of a process that can easily incorporate updated data, and how HRUs can be used to estimate runoff volumes and loading of various stormwater pollutants. The HRU approach can be used throughout Massachusetts with minimal modification, and can potentially be adapted for future use throughout the larger SNEP Region.
Tim Pasakarnis, Water Resources Analyst, Cape Cod Commission
Emma Curran, GIS Analyst, Cape Cod Commission