DESIGN - Development Facilitators, Inc. (DFI) provided site development planning and engineering for a Mixed-Use Development comprising of 188,000 square feet of Residential, 45,000 square feet of Retail, and 29,000 square feet of Office use. The site is adjacent to an unnamed tributary to the Severn River. The project included a hydrologic analysis of the flood plain utilizing TR-55 and HEC-RAS. The on-site stormwater management utilized underground infiltration and an extended detention facility to address water quality and quantity stormwater management. Pre-treatment for infiltration was addressed using grass channels and pre-treatment sump trenches. The development required a determination and delineation of the flood plain that involved a hydrologic study of the watershed using TR-55 and water surface profiling using HEC-RAS. The site was designed using both open and closed system storm water conveyance systems. The site utilized storm water credits to the maximum extent possible including sheet flow to conservation area, non-roof top disconnect credit, and grass swale credit. The site outfall analysis included a hydrologic and hydraulic analysis of the downstream Shipley’s Choice Pond to ensure safe convenience of the 100-year storm event. DFI provided all civil engineering services including land planning, creating site design standards, erosion and sediment control plans, landscape plans, forest stand conservation plans, public water and sewer plans, and public road plans for development of the project in addition to conducting community outreach meetings.
STORMWATER MANAGEMENT INSPECTION AND CERTIFICATION- DFI provided field inspection for the installation of the underground stormwater management detention facility and the infiltration trenches. The inspection included verifying size depth and the location of each device, shop drawing review of pipe components ordered for the construction of the detention facility, verifying the soils within the bottom of the facilities, inspection of the placement of filter fabric, geo-grid, observation wells and piping. Other duties included observing and keeping a photo record of the construction of the devices for proper placement of stone and closing up the trench. DFI’s inspector also ensured that the trench was blocked off from receiving drainage until all upstream areas were stabilized. The inspector’s responsibility also included a photo outfall tour of the site outfall to the point of investigation along with preparing a pre-developed sensitive area study.