Runoff = 0.09 cfs @ 12.22 hrs, Volume= 0.014 af, Depth= 1.83"
Routed to Link 18L : Study Area Road Undetained (Total)
Runoff by SCS TR-20 method, UH=Delmarva, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs
NOAA 24-hr D 100-Year-Current Rainfall=9.48"
| Area (ac) | CN | Description |
|---|---|---|
| 0.090 | 39 | >75% Grass cover, Good, HSG A |
| 0.090 | 39 | 100.00% Pervious Area |
| Tc (min) | Length (feet) | Slope (ft/ft) Velocity (ft/sec) Capacity (cfs) |
| 4.8 | 58 | 0.0300 0.20 |
| Sheet Flow, A-B | ||
| Grass: Short n= 0.150 P2= 4.04" | ||
| 4.8 | 58 | Total Increased to minimum Te = 10.0 min |
4.8 58 Total, Increased to minimum Tc = 10.0 min
Subcatchment 19S: Study Area Road Undetained (Perv)
| 2026-02 Existing and Proposed | NOAA 24-hr D | 100-Year-Current | Rainfall=9.48″ |
|---|---|---|---|
| Prepared by Dynamic Engineering | Printed | 2/10/2026 | |
| HydroCAD\circledR 10.20-8a s/n 08640 | © 2025 HydroCAD Software Solutions LLC | Page 104 |
| Inflow Area = | 0.740 ac, 97.30% Impervious, Inflow Depth = 9.04" for 100-Year-Current event |
|---|---|
| Inflow = | 4.30 cfs @ 12.19 hrs, Volume= 0.557 af |
| Outflow = | 1.33 cfs @ 12.73 hrs, Volume= 0.557 af, Atten= 69%, Lag= 32.5 min |
| Discarded = | 0.71 cfs @ 12.73 hrs, Volume= 0.505 af |
| Primary = | 0.62 cfs @ 12.73 hrs, Volume= 0.052 af |
| Routed to Link 14L: Study Area West (Total) | |
Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 119.50' @ 12.73 hrs Surf.Area= 3,001 sf Storage= 5,809 cf
Plug-Flow detention time=37.4 min calculated for 0.557 af (100% of inflow) Center-of-Mass det. time=37.3 min (788.0 - 750.6)
| Volume | Invert | Avail.Storage | Storage Description |
|---|---|---|---|
| #1A | 117.50' | 0 cf | 31.63'W x 94.88'L x 3.00'H Field A |
| #2A | 117.50' | 8,729 cf | 8,999 cf Overall - 8,999 cf Embedded = 0 cf x 40.0% Voids ACO StormBrixx SD 1 x 384 Inside #1 Inside = 23.7"W x 36.0"H => 5.75 sf x 3.95'L = 22.7 cf Outside = 23.7"W x 36.0"H => 5.93 sf x 3.95'L = 23.4 cf 384 Chambers in 16 Rows |
8,729 cf Total Available Storage
Storage Group A created with Chamber Wizard
| Device | Routing | Invert | Outlet Devices |
|---|---|---|---|
| #1 | Primary | 117.50' | 15.0" Round Culvert L= 22.0' RCP, groove end projecting, Ke= 0.200 Inlet / Outlet Invert= 117.50' / 117.40' S= 0.0045'' Cc= 0.900 n= 0.013, Flow Area= 1.23 sf |
| #2 | Device 1 | 118.81' | 6.0'' Vert. Orifice C= 0.600 Limited to weir flow at low heads |
| #3 | Discarded | 117.50' | 10.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = -4.00' |
| Discarded OutFlow Max=0.71 cfs @ 12.73 hrs HW=119.49' (Free Discharge) —3=Exfiltration ( Controls 0.71 cfs) | |||
| Primary OutFlow Max=0.62 cfs @ 12.73 hrs HW=119.49' (Free Discharge) —1=Culvert (Passes 0.62 cfs of 6.91 cfs potential flow) —2=Orifice (Orifice Controls 0.62 cfs @ 3.17 fps) | |||