CG Base Portsmouth: Grass Channel BMP Design

Abstract

This capstone project focuses on designing a grass swale and investigating additional effective stormwater Best Management Practices (BMPs) at CG Base Portsmouth. The proposed grass swale BMP is intended to improve local water quality and support compliance with pollutant reduction requirements established under the Chesapeake Bay Preservation Act Total Maximum Daily Load (TMDL) framework. As part of the broader Base Portsmouth Storm Water Improvements initiative, the design addresses runoff from a newly constructed 200-stall parking lot and is sized to manage a 10-year, 24-hour rainfall event of 6.77 inches in accordance with the NOAA Type C distribution. The project supports phased compliance milestones (2018, 2023, and 2028) while integrating resilient infrastructure with quality-of-life enhancements for base personnel.