SMC converted an existing stormwater retention pond into an extended detention wetland to create stormwater management credits for a County in Maryland’s MS4 permit. The scope of work included modifications to the existing concrete outlet structure and regrading of the pond to increase storage capacity. SMC installed manholes, concrete, and HDPE piping to convey runoff from the surrounding public parking areas into the new forebay areas created to retain and treat the water prior to discharging it into the main pond area.
SMC also created microtopography in the ponding area to facilitate the creation of low and high marsh environments. Specific plants were planted based on their tolerance for water in the root zone. Additional native shrubs and trees were planted to increase the overall habitat value of the project. To ensure longterm maintenance of the project, a geogrid road system was installed to ensure access to the pond embankment and ponding area.