SW6191102_mcphail revised swale 8 calcs-191206_12/6/2019

OBJECTIVE:
SOLUTIONS:
RUNOFF CONDITIONS
MAXIMUM
Slope Condition
SHEAR STRESS:
RECOMMENDED LINING:
CHECK 1" STORM EVENT
HYDRAULIC RETENTION TIME:
TERMINOLOGY:
CONVEYANCE AND TEMPORARY DIVERSION SWALE �13
McPhail Meadows
Proposed Conveyance Swale Capacity
Verify Capacity of Proposed Conveyance Swale Based Upon 1 in/hr event.
Check that swale will non-erosively pass 10-year event
Mannings Flow Equation
c: I T (in/hr): A (ac : 110:
0.4 1.00 F-o.83 7.97
Q V Event = 0.33 cis
Q 10 year event= 2.65 cfs
-
0.310
ft (min.flow depth for I"storm) =
2.15 FT 2
d =
ft (for to year storm event) P =
7.96 FT
0,98
n =
(computed) R =
0.27
0.0 0
6
B =
ft (min. width) Q 1" Storm =
1.99 CFS
Z Left =
:1 (ovg between culverts) V 1" Storm =
0.93 FPS
3
Z Right =
:1 (avg between culverts) Q 10 year
3
Avg. S =
ft (avg. slope) W=1
7.86 FT
002
V 10 =1
1.78
IFPS
1= shear stress
T= 0.039 PSF
Seed and Mulch With Contractor's Blend
Q 1" Storm = 1.99 cfs
Swale Length x [E/f
Available Depth (With 6"Freeboard) =
Total Swale Depth = 1 ft
Q= Peak Discharge, (CFS)
V = Permissible Velocity, (FPS)
d = Maximum Depth of Water, (FT)
Vt = Trial Velocity, (FPS)
n = Manning's "n" Coefficient
V`R = Product of Velocity and Hydraulic Radius
B = Bottom Width of Channel, (FT)
Z = Side Slope of Channel (Z:1)
d= 0.31 FT
S= 0.00 FT.
Side Slope = 3.00 :1
Swale Capacity at
Available Depth =, 356.25 cf
Hydraulic Retention = 2.98 minutes
A =Cross -Sectional Area of Flow, (FTA2)
P =Wetted Perimeter of the Flow, IFT)
R = Hydraulic Radius, (FT)
S = Slope of the Channel, (FT/FT)
Q = Discharge, (CFS)
V Velocity, (FPS)
W Top Width of Water in Channel, (Fr)
Y Specific Weight of Water (62.4 PCF)
CHANNEL LINING:
With velocities less than 2 fls use Seed and Mulching
With velocites greater than 2 f/s use Temporary Ditch Liner
: if T < I then use Coit Wattle against silt fence
: if T > I then use other lining

OBJECTIVE:
SOLUTIONS:
RUNOFF CONDITIONS
MAXIMUM
Slope Condition
SHEAR STRESS:
RECOMMENDED LINING:
CHECK 1" STORM EVENT
HYDRAULIC RETENTION TIME:
TERMINOLOGY:
CHANNEL LINING:
CONVEYANCE AND TEMPORARY DIVERSION SWALE
8A
McPhail Meadows
Proposed Conveyance Swale Capacity
Verify Capacity of Proposed Conveyance Swale Based Upon 1 in/hr event.
Check that swale will non-erosively pass 10-year event
Mannings Flow Equation
c: I T (In/hr): A (ac): 1 10:
0.4 1.00 4.06 7.97
Q 1" Event = 1.62 cfs
Q 10 year event= 12.94 cfs
=
0.3
(min. flow depth for I" storm) A =
2.15 FT-2
d =
ft (for 10 year storm event) P =
7.96 FT
0,9g
n =
(computed) R =
0.27
0.030
6
B =
ft (min. width) Q 1" Storm =
1.99 CFS
Z Left =
:1 (avg between culverts) V 1" Storm =
0.93 FPS
3
Z Right =
:1 (avg between culverts) Q 10 year =
5.61 cfs
3
Avg. 5=
ft/ft (avg. slope) W=1
7.85 FT
V 10 =1
1.78
IFPS
T= 0.039 PSF
Seed and Mulch With Contractor's Blend
Q 1" Storm =
1.99 cfs
Swale Length =alft
IfAvailable
Depth (With 6"
Freeboard) =
Total Swale Depth =
1 ft
Q = Peak Discharge, (CFS)
V = Permissible Velocity, (FPS)
d = Maximum Depth of Water, (FT)
Vt = Trial Velocity, (FPS)
n = Manning's "n" Coefficient
V'R = Product of Velocity and Hydraulic Radius
B = Bottom Width of Channel, (FT)
Z = Side Slope of Channel (Z:1)
d=I 0.31 FT
S= 0.00 FT.
Side Slope = 3.00 :1
Swale Capacity at
Available Depth 356.25 cf
Hydraulic Retention = 2.98 minutes
With velocities less than 2 f/s use Seed and Mulching
With velocites greater than 2 f/s use Temporary Ditch Liner
: if T < 1 then use Coir Wattle against silt fence
: if T > l then use other lining
A = Cross -Sectional Area of Flow, (FT^2)
P = Wetted Perimeter of the Flow, (FT)
R = Hydraulic Radius, (FT)
S = ISIope of the Channel, (FT/FT)
Q = Discharge, (CFS)
V = Velocity, (FPS)
W = 4ecific
p Width of Water in Channel, (FT)
Y = Weight of Water (62.4 PCF)