Rationale:
Installing a multi-inlet riser structure between Duck Pond and Silver Lake will help control flooding when the area is introduced to a 5-year storm. This structure will reduce the depth of the water in Duck Pond and Silver Lake. The riser structure will not have a significant impact on water quality, and subsequent additional solutions are necessary in order to reduce nutrient and sediment loading prior to discharge into the Elizabeth River.
Dimensions:
Top View
Discharge View
Side View
Rationale:
In order to mitigate TN, TP, and TSS within Silver Lake and Duck Pond, our design optimally entails an establishment of a 35 ft undisturbed, unmowed Bermuda and Zoysia turf grass buffer that would treat overland flow directly entering Silver Lake from residential areas. Implementation would reduce 8.2% of TN and TP entering the Elizabeth River and 10.9% of TSS.
Rain barrels' main goal is to reduce runoff, therefore limiting the transport of pollutants.
If 10% of homeowners installed a rain barrel, approximately 1000 gallons of water would be captured per rainstorm as runoff from 1/2 of each home's roof.
https://fcmponline.com/products/rc4000-rain-catcher-rain-barrel
Bioretention cells reduce runoff by collecting stormwater and removing nutrients using specific vegetation . If all homes installed bioretention cells, 4.32% of TN, 3.71% of TP, and 2.70% of TSS discharged into the Elizabeth River from Silver Lake would be removed.
https://www.3riverswetweather.org/green/green-solution-rain-garden
Floating wetlands will reduce nutrients that are already in the pond and lake through uptake by the plants.
Removal rates are based on surface area coverage, and large-scale implementation of floating wetlands can become expensive.
13.6% coverage of Silver Lake and Duck Pond would remove 52.7% of TN and 54.5% of TP discharged to the Elizabeth River from Silver Lake.