J- -14-02 STORMWATER MANAGEMENT REPORT-ANNAPOLIS

ATTACHMENT 1604000-14-02

STORMWATER MANAGEMENT REPORT-ANNAPOLIS JANUARY 2017

BMP ID#:

SWM-16

Name:

Bioretention at Turf Rugby Field

Type:

Bioretention

Location:

249 Greenbury Point Road, Building NA687 (Lat. 38.99127, Long. -76.45895)

TOPIC

General
Information

DETAIL

Year Installed
Drainage Area
Impervious Area
Total Area Treated
Treated Storm
Proposed Flow
Pollutants Treated
Shape
Length, Width, Depth
Slope(s)
Capacity

Inflow Pipe Length/Diameter

Design Details

Forebay Length, Width, Depth

Filter Media Type/Thickness (e.g.
Mulch Layer, Planting Media, Gravel,
etc.)
Observation Well Details
Vegetative Cover Type / Landscaping
Underdrain Details
Outflow Details
Overflow Design Details

INFORMATION

2009 (date on design drawings)

4.1 Acres

18,295.2 sq ft (0.42 ac) (master spreadsheet)
135,036 sq ft (3.1 ac) (master spreadsheet)
Unknown
Total Phosphorus, Metals, TKN, Total Suspended Solids,
Organics, Bacteria, Trash/Debris
Rectangular
3,707 sf (150' x 25' x 4.25')
0.5 % turf field, 3:1 edge of turf field, unknown swale. 15,900 cf (Approximately)
Inflow from turf underdrain –8” perforated pipe storm
drain to stone riprap to grass swale on east side of
bioretention. Grass swales on both sides of bioretention, 6 ft bottom width, 3:1 side slopes, eastern swale- ~640 L ft, western swale- ~ 220 L ft. Gravel diaphragms near
discharge 6’wide by 2’ long by 2’ deep: 6” of #2 cobble stone, an d 1.5’pea gravel, lined with filter fabric on sides and bottom.
N/A. A portion of the stormwater comes from the turf
fields underdrain system. The turf field’s profile: 2.5” pile fieldturf with 1.75” of infill, 2” of top stone
compacted to 95%, 4” of base stone compacted to 95%
proctor with a 0.5% slope to a lined stone trench with a perforated round drain with sock approximately 18”
below ground surface. This perforated pipe is also at a 0.5% slope, 210 LF and discharges to the grass swale.
3” mulch, 2.5” planting soil, 1’ gravel
6” PVC placed 4” above grade on base plate at the
bottom of the gravel layers. Perforations in the gravel layer only (1’ thick).
8 trees (Sweetbay Magnolia, Magnolia virginiana), 55
shrubs (Sweet Pepperbush, Clethra alnifgolia), 105
herbaceous plants (Blue Flag, Iris versicolor)
6” perforated PVC, 104 LF.
Type “D” inlet at Wsel of 10.5 ft to a 6” PVC underdrain at 0.5% slope to stone rip-rap outfall, 132 LF.
Stone weir (length: 18 ft, elevation, 10 ft)