Annapolis Harbour Center Pond Retrofit
Anne Arundel County, MD
CLIENT: Anne Arundel County Department of Public Works
Prime: BayLand Consultants & Designers, Inc.
Completed: September 2017
Construction Cost: $400,000
BayLand was selected to provide engineering design, permitting and construction management for the retrofit of the existing SWM pond for the Annapolis Harbour Center. The existing pond was constructed prior to 2002 and did not provide water quality treatment consistent with the most current Maryland Department of the Environment (MDE) design requirements. The facility was selected for retrofit to provide impervious area treatment credit towards the County’s National Pollutant Discharge Elimination System (NPDES) municipal separate storm sewer system (MS4) permit and contribute sediment and nutrient removal credit towards meeting the South River and Chesapeake Bay approved Total Maximum Daily Load (TMDL).
BayLand designed the retrofit to maximize the water quality treatment and channel protection volume provided while maintaining the existing flood control through additional wet pond storage and innovative low flow modifications. The grading plan utilized a wetland berm to create sediment forebays for two of the facility inlets and established safety and aquatic benches to improve facility safety and create habitat enhancements. The landscaping plan promoted a diversity of native wetland vegetation to facilitate habitat and improve the pond aesthetics. A clay liner was proposed to provide an impervious core for the embankment and bring the facility into compliance with MD-378 Dam Safety and the MDE Embankment Retrofit Guidelines. The access roads were also re-established for improved long-term facility maintenance.
BayLand completed the design and permitting in Spring 2017 followed by engineering oversight during construction in Summer 2017.