A combination of warm weather grasses, terrestrial and aquatic plants in and around the spring

Stormwater Management Plan for College Springs ParkBenjamin Snyder, Andrew Jeffery, and Brandon Copeland

Biological Systems Engineering Department of Virginia Tech

Problem Description

AcknowledgementsDr. Mary Leigh Wolfe (Biological Systems Engineering)Dr. Gene Yagow (Biological Systems Engineering)

Pollutant Recommended levels

Baseflow Measurements

Stormevent Measurements

Total Nitrogen (TN) 0.69 mg/L * 15.33 mg/L 4.79 mg/L

Total Phosphorus (TP) 36.56 µg/L * 247.67 µg/L 2260 µg/L

Total Suspended Solids (TSS) 30 mg/L ** <1 mg/L 214 mg/L

Enhanced Vegetation

•EPA National nutrient recommendations for Eco-region IX** As recommended by VADQS handbook

Community Outreach

Daylighting

Stroubles Creek is impaired for benthic macroinvertebrates, with sediment identified as the primary stressor. College Springs Park is located in the Upper Stroubles Creek Watershed in Blacksburg, Virginia, which contains significant urban and agricultural land uses.

Site Description•1.25 acre park•236 acre drainage area•27% impervious area•Areas of interest

Design ProcessManagement practices where chosen based on water quality results and hydrologic analysis of the sub-watershed.

• Daylighting: Re-establishment of a once existing waterway• Water quality swale: Vegetated channel that allows for infiltration into an engineered soil matrix• Vegetation enhancement: Establishment of native plant species in and around a wetland

Hydrologic analysis was performed using ArcGIS and TR-55 software, indicating peak discharge values of 1.20 and 3.19 m3/s for the 2-yr and 10-yr storm events respectively.

Proposed Solutions

1) Wooded spring area2) Piped stream under park3) Berryfield drainage channel

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A community brochure has been developed in conjunction with SEEDS and the Town of Blacksburg to educate residents about their watershed.

Benefits / Potential Pollutant Removal EfficienciesDaylighting• Re-establish stream corridor• Decrease flow velocity via stream meandering• Increased biological uptake• Community AwarenessWater Quality Swale • TSS – 80%• TP – 35%• TN – 20 – 40%Vegetation Enhancement• Erosion control• Biological uptake• Provide wildlife habitat• Aesthetic value for community

Components:• Engineered Soil Matrix – 50% sand, 30% leaf mulch, 20% top soil• Perforated underdrains – Two 4’’ (0.10m) corrugated PVC pipes• Checkdams and Toe Protection – Height of 0.46m based on peak discharge of 10-yr storm event Species Amount Prices ($) Total

Indian Grass 5-7 lbs/ac 11.49/lb $32.17 Eastern Gamma Grass @ 0.4 ac 12.99/lb $36.37 Switch Grass = 2.8 lbs 6.5/lb $18.20 Black-Eyed Susan 1-8 oz/ac 24/lb $4.80 Maximillian Sunflower @ 0.4 ac 9.95/lb $1.99 Annual Lespedeza = 3.2 oz 1.70/lb $2.00 Partridge Pea 19.95/lb $3.99 Water Lotus 40 seeds 6.95 / 10 seeds $27.80 Water Lilly 20 / 5 seeds $80.00

Establishment of native vegetationaround 0.4 ac spring area.

Water Quality Swale

Stream channel dimensions were based on downstream measurements:• Wetted Perimeter: 1.28 m• Area: 0.11 m2

• Velocity: 0.18 m/s• Discharge: 0.068 m3/s

Cost of Implementation: $45,069

CostsConstruction: $3,280Maintenance: $116/yr