HomeMy WebLinkAboutSW6191102_MCPHAIL MEADOWS STORM AND EC CALCS_12/6/2019McPhail Meadows
Storm Water and Erosion & Sedimentation Control Calculations
Owner:
Southeastern Construction of Rockfish
771 Bostic Road
Raeford, NC 28376
McPhail Meadows 2
The certification shown below applies only to the items listed on this 'Table of Contents'
Drainage Area Map
Runoff Coefficient
Kirpich Equation
NOAA Rainfall Intensity
HDS-5 Culvert Capacity
Rip Rap Outlet Apron
Manning's n
Table of Contents
1 Page (Print to 11"x17"; print all others below to 8.5" x 111.)
1 Page
1 Page
1 Page
1 Page
2 Pages
3 Pages
Conveyance and Temporary Diversion Swales 9 Pages
Temporary Sediment Traps 4 Pages
HILLIARD - - ---
ENGINEERING
Author: Jarrod E. Hilliard, PE, CFM
PO Box 249 Sanford, NC 27331
(919) 352-2834
NC License No. P-0836
•CAR�C'� "
E
35
ro_
Date: 10/27/19
D RAI NAG E AREA MAP
�- -- - ------- _--
L --'
23o
00
O �
N.
two
N
RUNOFF COEFFICIENT
0
Table 8.03b
Value of Runoff Coefficient
(C) for Rational Formula
Land Use
C
Land Use
C
Business:
Lawns:
Downtown areas
0.70-0.95
Sandy soil, flat, 2%
0.05-0.10
Neighborhood areas
0.50-0.70
Sandy soil, ave.,
0.10-0.15
2-7%
Residential:
Sandy soil, steep,
0.15-0.20
Single-family areas
0.30-0.50
7%
Multi units, detached
0.40-0.60
Heavy soil, flat, 2%
0.13-0.17
Multi units, Attached
0.60-0.75
Heavy soil, ave.,
0.18-0.22
Suburban
0.25-0.40
2-7%
Industrial:
Heavy soil, steep,
0.25-0.35
Light areas
0.50-0.80
7%
Heavy areas
0.60-0.90
Agricultural land:
Parks, cemeteries
0.10-0.25
Bare packed soil
Smooth
0.30-0.60
Playgrounds
0.20-0.35
Rough
0.20-0.50
Cultivated rows
Railroad yard areas
0.20-0.40
Heavy soil no crop
0.30-0.60
Heavy soil with
Unimproved areas
0.10-0.30
crop
0.20-0.50
Streets:
Sandy soil no crop
0.20-0.40
Asphalt
0.70-0.95
Sandy soil with
Concrete
0.80-0.95
crop
0.10-0.25
Brick
0.70-0.85
Pasture
Heavy soil
0.15-0.45
Drives and walks
0.75-0.85
Sandy soil
0.05-0.25
Woodlands
0.05-0.25
Roofs
0.75-0.85
NOTE: The designer
must use judgement
to select the appropriate
C
value within the range
for the appropriate land use. Generally,
larger
areas with permeable
soils, flat slopes, and dense vegetation
should
have lowest C values.
Smaller areas
with slowly permeable
soils, steep
slopes, and sparse vegetation should
be assigned highest C
values.
Source: American Society of Civil Engineers
8.03.6 Rev. 6/06
KIRPICH EQUATION
FOR TIME OF CONCENTRATION
McPhail Meadows
KIRPICH EQUATION
FOR TIME OF CONCENTRATION COMPUTATIONS
T. = [ K/1281 [L3/H]0.385
K: 1
L: 481.63
H: 7
T,: 4.63 Minutes
Use: 5.00 minutes for all
NOAA RAINFALL INTENSITY
Precipitation Frequency Data Server
https ://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=34.9982&...
NOAA Atlas 14, Volume 2, Version 3
' Location name: Raeford, North Carolina, USA*''��"
Latitude: 34.9982°, Longitude:-79.1082' e
Elevation: 237.08 ft** I,
* source: ESRI Maps
** source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonnin, D. Martin, B. Lin, T. Parzybok, M.Yekta, and D. Riley
NOAA, National Weather Service, Silver Spring, Maryland
PF tabular I PF-graphical I Maps & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches/hour)l
Average
recurrence interval (years)
Duration
1 2 5 25 50 100 200 500 1000
000��0000�
5.22 6.17 7.19 8.89 6 9.510.2 10.8 11.6 12.1
5-min
�
(4.74 5.78) (5.60 6.83) (6.53 7.97) (7.21 8.80)1 (8.02-9.80) (8.60-10.5) (9.13 11.2) (9.62-11.9)
4.17 4.93 5.76 F 7.09 F 7.61 F 8.56 9.14 9.55
10-min
(3.79 4.62) (4.48-5.46) (5.23-6.38) 1 (6.38-7.81) (6.85-8.38) (7.25 8.91) (7.63-9.41) (8.06-10.0)
3.48 F 4.13 4.86 5.37 5.99 6.43 6.83 7.20 7.67 7.99
15-min
F(4.86-5.93)
(3.16-3.85) (3.75-4.58) (4.41-5.38) (5.40-6.60) (5.78-7.07) 1 (6.11-7.51) 1 (6.41-7.92)
2.38 2.85 3.45 3.89 4.44 4.84 5.23 5.61 6.106.47
30-min
(2.16-2.64) (2.59-3.16) (3.13-3.82) (3.52-4.30) (4.00-4.89) (4.35-5.33) (4.68 5.75) (4.99-6.16) (5.38-6.7-]E(5 67 7.11)
1.49
1.79
2.21
2.53
2.95
3.28
3.60
3.93
4.72
60-min
=(34.81)
(1.35-1.65)
(1.63-1.98)
(2.01 2.45)
(2.29 2.80)
(2.66 3.26)
(2.95 3.61)
(3.22 3.96)
(3.50 4.32)
(4.14 5.19)
0.865 F 1.05 1.32 1.53 1.81 2.03 2.25 2.49 2.80 3. 55
2-hr
(0.778-0.975) (0.944-1.18) (1.18-1.48) 1 (1.61-2.03) 1 (1.80-2.28) 1 (2.18-2.79) 1 (2.43-3.13) (2.63-3.41)
0.611 0.739 0.934 1.09 1.31 1.48 1.66 1.86 2.13 2.35
3-hr
(0.549 0.690) (0.665 0.835) (0.838 1.05) (0.976 1.23) (1.16 1.47) (1.31 1.66) (1.46 1.87) (1.62 2.08) (1.83 2.38) (2.00 2.63)
0.365 0.443 0.559 0.654 0.786 0.894 1.01 1.13 1.30 1.44
6-hr
(0.330-0.408) (0.400-0.494) (0.505-0.623) (0.588-0.728) (0.701-0.872) (0.793-0.991) (0.887 1.12) (0.984 1.25) (1.12-1.44)
0.214 0.259 0.329 0.387 0.468 0.536 0.608 0.686 0.797 F 0.889
12-hr
(0.193-0.239) (0.234-0.290) (0.297-0.368) (0.347-0.431) (0.417-0.520) (0.473-0.594) (0.532-0.672) (0.593-0.757) (0.680-0.880) (0.748-0.980)
0.127 0.153 0.195 0.227 0.273 0.309 0.347 0.386 0.4 1 IF 0.484
24-hr
(0.118-0.137) (0.142-0.166) (0.180-0.210) (0.210-0.245) (0.251-0.294) (0.284-0.333) (0.318-0.374) (0.352-0.416) (0.400-0.475) (0.437-0.522)
0.073 0.089 F 0.112 0.130 0.155 0.175 0.196 0.218 0.248 0.271
2-day
(0.068 0.079) (0.083-0.095) (0.104-0.120) (0.120-0.139) (0.143-0.167) (0.161-0.188) (0.180-0.211) (0.199-0.234) (0.225-0.267) (0.246-0.292)
F--0-.0-5-2-11 0.063 F 0.078 0.091 0.108 0.122 0.136 0.151 0.172 0. 888
3-day
(0.049 0.056) (0.059-0.067) (0.073-0.084) (0.085-0.097) (0.100-0.116) (0.113-0.131) (0.126-0.146) (0.139-0.162) (0.157-0.184) (0.171-0.202)
0.041 0.050 F 0.062 0.072 0.085 0.096 0.107 0.118 0.134 F 0.146
4-day
(0.039 0.044) (0.047-0.053) (0.058-0.066) (0.067-0.076) (0.079-0.091) (0.089-0.102) (0.098-0.114) (0.109-0.126) (0.122-0.143) (0.133-0.156)
0.027 0.033 0.040 I 0.046 0.055 0.061 0.068 0.075 0.084 F 0.092
7-day
(0.026 0.029) (0.031-0.035) (0.038-0.043) (0.043-0.050) (0.051-0.058) (0.057-0.065) (0.063-0.073) (0.069-0.080) (0.077-0.090) (0.084-0.099)
0.022 0.026 F 0.032 0.036 0.042 0.047 0.051 0.056 0.062 F 0.0 77
10-day
(0.021-0.023) (0.025-0.028) (0.030-0.034) (0.034-0.038) (0.039-0.045) (0.043-0.049) (0.048-0.054) (0.052-0.059) (0.058-0.066) (0.062-0.072)
0.015 0.018 1 0.021 0.024 0. 227 0.030 0.033 0.036 0.039 IF 0. 442
20-day
(0.014 0.016) (0.017-0.019) (0.020-0.022) (0.022-0.025) (0.025-0.029) (0.028-0.032) (0.031-0.035) (0.033-0.038) (0.036-0.042) (0.039-0.045)
0.012 0.015 F 0.017 0.019 0.021 0.023 0.025 0.027 0.030 0.032
30-day
(0.012-0.013) (0.014-0.015) (0.016-0.018) (0.018-0.020) (0.020-0.023) (0.022-0.025) (0.024-0.027) (0.025-0.029) (0.028-0.032) (0.029-0.034)
0.010 0.012 0.014 0.015 0.017 0.019 0.020 0.021 0.023 0.024
45-day
(0.010-0.011) (0.012-0.013) (0.013-0.015) (0.015-0.016) (0.016-0.018) (0.018-0.020) (0.019-0.021) (0.020-0.023) (0.022-0.024) (0.023-0.026)
0.009 F 0. 111 F 0.012 0.014 0. 115 F 0. 116 F 0. 117 0.018 0.020 0. 221
60-day
�(0.009-0.010)
(0.010-0.011) (0.012-0.013) (0.013-0.014) (0.014-0.016) (0.015-0.017) (0.016-0.018) (0.017-0.019) (0.019-0.021) (0.020-0.022)
Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for
a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not
checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values.
Please refer to NOAA Atlas 14 document for more information.
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PF graphical
1 of 4 9/28/2019, 2:55 PM
H DS-5 CULVERT CAPACITY
PROJECT: HC1901
STATION:
5+60
CULVERT EVALUATION
FORM
McPhail Meadows
Sheet:
1
Of
1
DESIGNER/DATE:
JEH
10/25/2019
Evaluate Proposed Culvert
REVIEWER/DATE:
JEH
10/25/2019
HYDROLOGICAL DATA
1ROADWA7 ELEVATION 234.63 Ift.
W X METHOD: Rational
233.63
jElha (ft)
X DRAINAGE AREA: 2.49
ac
WATER
WA
H
0
� CHANNEL SHAPE:
a
- - -
- - - - - -
- Elsf 232.00 — —
— —
— — WATER SURFACE
w
ROUTING:
••.. .........
ORIGINAL STREAM
—T�/�/
.................
•
DESIGN FLOWS/TAILWATER
R.I. (YEARS) FLOW (cfs)
TW (ft)
s = So - T / Lo
25 1 8.85
1 0.25
231.83
jEli (ft)
IS= 1 1.00%
231.3
jElo (ft)
Lo 1 53
CULVERT DESCRIPTION
FLOW PER
MATERIAL - SHAPE - SIZE (in) - ENTRANCE
TOTAL FLOW
BARREL Q / N
r NUMBER OF BARRELS TO TRY:
1
SHAPE: C=CIRCULAR, A=ARCH, B=BOX
Q (cfs)
(1)
RC ICI 18 O
8.85
8.85
HEADWATER CALCULATIONSINLET
o m 2
c 3 m
<j = w
w
E
E
CONTROL
OUTLET CONTROL
HWI / D
T
Elhi
TW
do + D
ho
H
EI ho
(2)
Hwi
(3)
(4)
(5)
do
2
(6)
ke
(7)
(8)
1.2
1.80
0.17
233.63
0.25
1.22
1.36
1.36
0.9
233.56
233.63
O.K.
(Chart 1 B)
(Chart 4B)
(Chart 5B)
F--
(1) USE Q / NB FOR BOX CULVERTS(PIQ"M27^2)-(M27^2*ACOS(M28/M27)-M28"SQRT(M27^2-M28^2)
(2) FROM HDS-5 DESIGN CHARTS
(3) T = Hwi - (ELhd-Elsf), T IS ZERO FOR CULVERTS ON GRADE
(4) Elhi = Hwi+Eli
(5) TW BASED ON DOWNSTREAM CONTROL OR FLOW DEPTH IN CHANNEL
(6) ho = TW or (dc + D/2), (WHICHEVER IS GREATER)
(7) FROM HDS-5 DESIGN CHARTS
(8) Elho = Elo + H + ho
r (ft.):l 0.75
d (ft):1 1.05 Over Half
Area of Pipe (tt-):
1.77
0.885
ow rea
9.77
Outlet Velocity (ft/s):
5.00
of Pipe Elevation @ Inlet (ft):
233.58
Cover @ CL Road (ft):
9.32 1
Use Min. Cl. IV
)TF• FRFFR(10RI1 = 1'
RIP RAP OUTLET APRON
User Input Data
Calculated Value
Reference Data
Designed By: JEH 10/25/2019
Checked By: JEH 10/25/2019
Company: Hilliard Engineering, PLLC
Project Name: McPhail Meadows
Project No.: HC1901
Site Location (City/Town) Raeford, NC
Culvert Id. Sta 5+60
Total Drainage Area (acres) 2.49
Step 1. Determine the tailwater depth from channel characteristics below the
pipe outlet for the design capacity of the pipe_ If the tailwater depth is less
than half the outlet pipe diameter_ it is classified minimum tailwater condition.
If it is greater than half the pipe diameter_ it is classified maximum condition.
Pipes that outlet onto wide flat areas N%rith no defined channel are assumed
to have a mnnnnim tailwater condition unless reliable flood stage elevations
show otherwise.
Outlet pipe diameter, Do (in.)
Tailwater depth (in.)
Minimum/Maximum tailwater?
Discharge (cfs)
Velocity (ft./s)
18
0.25
Min TW (Fig. 8.06a)
7.94
4.5
Step 2. Based on the tailwater conditions determined in step 1. enter Figure
8.06 a or Figure 8.06b. and determine d50 riprap size and minimum apron length
(L,). The d5o size is the median stone size in a well -graded riprap apron_
Step 3. Determine apron width at the pipe outlet, the apron shape, and the
apron width at the outlet end from the same figgue used in Step 2.
Riprap d50, (ft.)
Minimum apron length, La (ft.)
Apron width at pipe outlet (ft.)
Apron shape
Minimum TW
Figure 8.06a
0.25
9
4.5
Trapezoidal
Maximum TW
Figure 8.06b
Apron width at outlet end (ft.) 10.5 1.5
Step 4. Derernune the maximum stone diameter:
d„ ,al = 1.5 x d50
Minimum TW
Max Stone Diameter, dmax (ft.) 0.375
Step 5. Deternune the apron thickness:
Apron Thickness(ft.)
Apron thickness = '1.5 x dF,,,
Minimum TW
0.5625
Maximum TW
0
Maximum TW
0
Step 6. Fit the riprap apron to the site by making it level for the nunimum
length. La from Figure 8.06a or Figure 8.06b. Extend the apron farther
doiNmstream and along channel banks until stability is assured. Keep the
apron as straight as possible and align it with the flow of the receiving stream.
Make any necessary alignment bends near the pipe outlet so that the entrance
into the receiving stream is straight. -
Some locations may require lining of the entire channel cross section to assure
stability.
It may be necessary to increase the size of riprap where protection of the
channel side slopes is necessary (Appendix 8.05). Where overfalls exist at
pipe outlets or flows are excessive, a plunge pool should be considered, see
page 8.06.8.
MANNINGS n
FOR CONVEYANCE AND TEMPORARY DIVERSION SWALES
This section describes a method for estimating the roughness coefficient n for
use in hydraulic computations associated with natural streams_ floodways. and
excavated channels. The procedure applies to the estimation of n in Mannuis-s
formula (Appendix S.05).
Designed By: JEH Date: 09/28/19
Checked By: JEH Date: 09/28/19
Company: Hilliard Engineering, Pllc
Project Name: McPhail Meadows
Project No.:
Site Location (City/Town) Hoke County
Site Id. n/a
Step 1. Selection of basic value of n. Select a basic n value for a straight,
uniform. smooth channel in the natural materials involved. The conditions of
straight alignment, uniform cross section, and smooth side and bottom surfaces
without vegetation should be kept in mind. Thus. basic n varies only with the
material than forms the sides and bottom of the channel. Select the basic n for
natural or excavated channels from Table 8.04a. If the bottom and sides of a
chiiwiel consist of different materials. select an intermediate value.
Channels in earth
Basic n value i(n=0.020) 1 0.02 Table 8.04a
Step 2. Selection of modifying value for surface irregularity-. This factor
is based on the degree of roughness or irregularity of the surfaces of channel
sides and bottom. Consider the actual surface irregularity. first in relation
to the degree of surface smoothness obtainable with the natural materials
involved_ and second in relation to the depths of flow expected. If the surface
irregularity is comparable to the best surface possible for the channel materials,
assign a modifying value of zero. Irregularity induces turbulence that calls for
increased modifying values. Table 8.04b may be used as a guide to selection
of these niodifvinQ values.
Modifying value: channel
surface irregularity Smooth (0.000) 0 Table 8.04b
Step 3. Selection of modifying value for variations in the shape and size of
cross sections. In considering this factor, judge the approximate magnitude of
increase and decrease in successive cross sections as compared to the average.
Gradual and uniform changes do not cause significant turbulence. Turbulence
increases with the frequency and abruptness of alternation from large to small
Annnel .rrtinn,,
1uwaa . -1--- .
Shape changes causing the greatest turbulence are those for which flow shifts
from side to side in the channel. Select modifying values based on Table
8.04c.
Modifying value: channel
cross section Gradual (0.000) 0 Table 8.04c
Step 4. Selection of modifying value for obstructions. This factor is based
on the presence and characteristics of obstructions such as debris deposits.
stumps, exposed roots. boulders, and fallen and lodged logs. Take care that
conditions considered in other steps not be double -counted in this step.
In judging the relative effect of obstructions. consider the degree to which
the obstructions reduce the average cross -sectional area at various depths and
the characteristics of the obstructions. Sharp -edged or angular objects induce
more turbulence than curved, smooth -surfaced objects. Also consider the
transverse and longitudinal position and spacing of obstructions in the reach.
Select modifying values based on Table 8.04d.
Modifying value: effect of
obstructions Negligible (0.000) 0 Table 8.04d
Step 5. Selection of modifying value for vegetation. The retarding effect
of vegetation is due primarily to turbulence induced as the water flows around
and between limbs. stems, and foliage and secondarily to reduction in cross
section_ As depth and velocity increase, the force of flowing water tends to
bend the vegetation. Therefore, the ability of vegetation to cause turbulence is
related to its resistance to bending. Note that the amount and characteristics of
foliage vary seasonally. In judging the retarding effect of vegetation, consider
the following: height of vegetation in relation to depth of flow, its resistance to
bending, the degree to which the cross section is occupied or blocked, and the
transverse and longitudinal distribution of densities and heights of vegetation
in the reach. Use Table 8.04e as a guide.
Modifying value: vegetation ILow (0.005-0.010) 1 0.0075 1 Table 8.04e
Step 6. Computation of its for the reach. The first estimate of roughness
for the reach, ns, is obtained by neglecting meandering and adding the basic n
value obtained in step 1 and modifying values from steps _' through 5.
r7Y = n + i modifying values
Straight channel subtotal, ns 0.0275
Step 7. Meander. The modifying value for meandering is not independent of
the other modifying values. It is estimated from the n. obtained In step 67 and
the ratio of the meandering length to the straight length. The modifying value
for meandering may be selected from Table 8.04f
Length of meandering
channel (ft)
Length of straight line (ft)
Meander ratio (ft/ft)
Modifying value:
meandering of channel
Meandering modification
0
100
0
Minor (0.00) 0 Table 8.04f
0.000
'Step S. Computation of it for a channel reach -Mth meandering. Add the
modifV11ig value obtained in step 7, to ir,, obtamed m step b.
Final roughness coefficient,
n 0.028
CONVEYANCE AND TEMPORARY DIVERSION SWALES
OBJECTIVE:
SOLUTIONS:
RUNOFF CONDITIONS
MAXIMUM
Slope Condition
SHEAR STRESS:
CONVEYANCE AND TEMPORARY DIVERSION SWALE 1
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
F1.27
7.97
Q 1" Event =
0.51 cfs
Q 10 year event=
4.05 cfs
d=
0.095
ft (min. flow depth for t"storm)
A= 0.60 FT^2
d =
0.32
ft (for 10 year storm event)
P = 6.60 FT
n =
0.030
(computed)
R = 0.09
8 =
6
ft (min. width)
Q 1" Storm = 0.52 CFS
Z Left =
3
:1 (avg between culverts)
V 1" Storm = 0.88 FPS
Z Right =
3
:1 (avg between culverts)
Q 10 year = 4.13 cfs
Avg.S-1
0.007700
ft/ft (avg. slope)
W = 6.57 FT
V 10 =
1.85
FPS
T= Shear Stress Y= 62.4 PCF
T= 0.046 PSF d= 0.10 FT
S= 0.01 FT/FT
RECOMMENDED LINING: Seed and Mulch With Contractor's Blend
CHECK 1" STORM EVENT
HYDRAULIC RETENTION TIME: Q 1" Storm = 0.52 cfs
Bottom of Swale Length 40 If
Available Depth (With 6"
Freeboard) = 0.5 ft
Total Swale Depth = 1 ft
TERMINOLOGY:
Q =
Peak Discharge, (CPS)
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)
Side Slope = 3.00 :1
Swale Capacity at
Available Depth = 150.00 cf
Hydraulic Retention = 4.77 minutes
CIiANNEL LINING:
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 > 1 then use other lining
A= Cross -Sectional Area of Flow, (FT^2)
P = Wetted Perimeter of the Flow, (FT)
R = Hydraulic Radius, (FT)
S = Slope of the Channel, (FT/FT)
Q = Discharge, (CPS)
V = Velocity, (FPS)
W = Top Width of Water in Channel, (FT)
Y = Specific Weight of Water (62.4 PCF)
OBJECTIVE:
SOLUTIONS:
RUNOFF CONDITIONS
MAXIMUM
Slope Condition
SHEAR STRESS:
CONVEYANCE AND TEMPORARY DIVERSION SWALE 2
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:
0.9 1.00 FO.25 7.97
Q 1" Event = 0.23 cfs
Q 10 year event= 1.79 cfs
d = 0.047 ft (min. flow depth for 1"storm) A = 0.29 FT^2
d = 0.17 ft (for 10 year storm event) P = 6.30 FT
n = 0.030 (computed) R = 0.05
8 = 6 ft (min. width) Q 1" Storm = 0.23 CFS
Z Left = 3 :1 (avg between culverts) V 1" Storm = 0.79 FPS
Z Right = 3 :1 (avg between culverts) Q 10 year = 1.99 cfs
Avg.S=l 0.015500 IftIft (avg. slope) W = 6.28 FT
V 10 = 1.80 FPS
T= Shear Stress Y= 62.4 PCF
T= 0.045 PSF d= 0.05 FT
S= 0.02 FT/FT
RECOMMENDED LINING: Seed and Mulch With Contractor's Blend
CHECK 1" STORM EVENT
HYDRAULIC RETENTION TIME:
Q 1" Storm = 0.23 cfs
Swale Length =
If
Available Depth (With 6"
EEft
Freeboard)=
Total Swale Depth = 1
ft
TERMINOLOGY:
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)
Side Slope = 3.00 :1
Swale Capacity at
Available Depth = 56.25 cf
Hydraulic Retention = 4.10 minutes
CHANNEL LINING:
With velocities less than 2 f/s use Seed and Mulching
With velocites greater than 2 f/s use Temporary Ditch Liner
: if T < I then use Coir Wattle against silt fence
: if T > I then use other lining
A= Cross -Sectional Area of Flow, (FT^2)
P = Wetted Perimeter of the Flow, (FT)
R = Hydraulic Radius, (FT)
S = Slope of the Channel, (FT/FT)
Q = Discharge,(CFS)
V= Velocity, (FPS)
W = Top Width of Water in Channel, (FT)
Y = Specific Weight of Water (62.4 PCF)
OBJECTIVE:
SOLUTIONS:
RUNOFF CONDITIONS
MAXIMUM
Slope Condition
SHEAR STRESS:
CONVEYANCE AND TEMPORARY DIVERSION SWALE 3
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 FO.59 7.97
Q 1" Event = 0.24 cfs
Q 10 year event= 1.88 cfs
d = 0.048 ft (min. flow depth for 1"storm) A = 0.29 FT^2
d = 0.17 ft (for 10 year storm event) P = 6.30 FT
n = 0.030 (computed) R = 0.05
8 = 6 ft (min. width) Q 1" Storm = 0.24 CFS
Z Left = 3 :1 (avg between culverts) V 1" Storm = 0.80 FPS
Z Right = 3 :1 (avg between culverts) Q 10 year = 1.99 cfs
Avg.S=l 0.015500 IftIft (avg. slope) W = 6.29 FT
V 10 = 1.80 FPS
T= Shear Stress Y= 62.4 PCF
T= 0.046 PSF d= 0.05 FT
S= 0.02 FT/FT
RECOMMENDED LINING: Seed and Mulch With Contractor's Blend
CHECK 1" STORM EVENT
HYDRAULIC RETENTION TIME:
Q 1" Storm = 0.24 cfs
Swale Length =
If
Available Depth (With 6"
EEft
Freeboard)=
Total Swale Depth = 1
ft
TERMINOLOGY:
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)
Side Slope = 3.00 :1
Swale Capacity at
Available Depth = 56.25 cf
Hydraulic Retention = 3.96 minutes
CHANNEL LINING:
With velocities less than 2 f/s use Seed and Mulching
With velocites greater than 2 f/s use Temporary Ditch Liner
: if T < I then use Coir Wattle against silt fence
: if T > I then use other lining
A= Cross -Sectional Area of Flow, (FT^2)
P = Wetted Perimeter of the Flow, (FT)
R = Hydraulic Radius, (FT)
S = Slope of the Channel, (FT/FT)
Q = Discharge,(CFS)
V= Velocity, (FPS)
W = Top Width of Water in Channel, (FT)
Y = Specific Weight of Water (62.4 PCF)
OBJECTIVE:
SOLUTIONS:
RUNOFF CONDITIONS
MAXIMUM
Slope Condition
SHEAR STRESS:
CONVEYANCE AND TEMPORARY DIVERSION SWALE 4
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 FO.86 7.97
Q 1" Event = 0.34 cfs
Q 10 year event= 2.74 cfs
d = 0.060 ft (min. flow depth for 1"storm) A = 0.37 FT^2
d = 0.21 ft (for 10 year storm event) P = 6.38 FT
n = 0.030 (computed) R = 0.06
8 = 6 ft (min. width) Q 1" Storm = 0.35 CFS
Z Left = 3 :1 (avg between culverts) V 1" Storm = 0.93 FPS
Z Right = 3 :1 (avg between culverts) Q 10 year = 2.86 cfs
Avg.S=l 0.015700 IftIft (avg. slope) W = 6.36 FT
V 10 = 2.06 FPS
T= Shear Stress Y= 62.4 PCF
T= 0.059 PSF d= 0.06 FT
S= 0.02 FT/FT
RECOMMENDED LINING: Seed and Mulch With Contractor's Blend
CHECK 1" STORM EVENT
HYDRAULIC RETENTION TIME:
Q 1" Storm = 0.35 cfs
Swale Length =
If
Available Depth (With 6"
EEft
Freeboard)=
Total Swale Depth = 1
ft
TERMINOLOGY:
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)
Side Slope = 3.00 :1
Swale Capacity at
Available Depth = 75.00 cf
Hydraulic Retention = 3.61 minutes
CHANNEL LINING:
With velocities less than 2 f/s use Seed and Mulching
With velocites greater than 2 f/s use Temporary Ditch Liner
: if T < I then use Coir Wattle against silt fence
: if T > I then use other lining
A= Cross -Sectional Area of Flow, (FT^2)
P = Wetted Perimeter of the Flow, (FT)
R = Hydraulic Radius, (FT)
S = Slope of the Channel, (FT/FT)
Q = Discharge,(CFS)
V= Velocity, (FPS)
W = Top Width of Water in Channel, (FT)
Y = Specific Weight of Water (62.4 PCF)
OBJECTIVE:
SOLUTIONS:
RUNOFF CONDITIONS
MAXIMUM
Slope Condition
SHEAR STRESS:
CONVEYANCE AND TEMPORARY DIVERSION SWALE 5
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 F1.34 7.97
Q 1" Event = 0.54 cfs
Q 10 year event= 4.27 cfs
d = 0.080 ft (min. flow depth for 1"storm) A = 0.50 FT^2
d = 0.27 ft (for 10 year storm event) P = 6.51 FT
n = 0.030 (computed) R = 0.08
8 = 6 ft (min. width) Q 1" Storm = 0.55 CFS
Z Left = 3 :1 (avg between culverts) V 1" Storm = 1.10 FPS
Z Right = 3 :1 (avg between culverts) Q 10 year = 4.30 cfs
Avg.S=l 0.015000 IftIft (avg. slope) W = 6.48 FT
V 10 = 2.34 FPS
T= Shear Stress Y= 62.4 PCF
T= 0.075 PSF d= 0.08 FT
S= 0.02 FT/FT
RECOMMENDED LINING: Seed and Mulch With Contractor's Blend
CHECK 1" STORM EVENT
HYDRAULIC RETENTION TIME:
Q 1" Storm = 0.55 cfs
Swale Length =
If
Available Depth (With 6"
EEft
Freeboard)=
Total Swale Depth = 1
ft
TERMINOLOGY:
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)
Side Slope = 3.00 :1
Swale Capacity at
Available Depth = 112.50 cf
Hydraulic Retention = 3.42 minutes
CHANNEL LINING:
With velocities less than 2 f/s use Seed and Mulching
With velocites greater than 2 f/s use Temporary Ditch Liner
: if T < I then use Coir Wattle against silt fence
: if T > I then use other lining
A= Cross -Sectional Area of Flow, (FT^2)
P = Wetted Perimeter of the Flow, (FT)
R = Hydraulic Radius, (FT)
S = Slope of the Channel, (FT/FT)
Q = Discharge,(CFS)
V= Velocity, (FPS)
W = Top Width of Water in Channel, (FT)
Y = Specific Weight of Water (62.4 PCF)
OBJECTIVE:
SOLUTIONS:
RUNOFF CONDITIONS
MAXIMUM
Slope Condition
SHEAR STRESS:
CONVEYANCE AND TEMPORARY DIVERSION SWALE 6
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 FO.88 7.97
Q 1" Event = 0.35 cfs
Q 10 year event= 2.81 cfs
d = 0.090 ft (min. flow depth for 1"storm) A = 0.56 FT^2
d = 0.22 ft (for 10 year storm event) P = 6.57 FT
n = 0.030 (computed) R = 0.09
8 = 6 ft (min. width) Q 1" Storm = 0.39 CFS
Z Left = 3 :1 (avg between culverts) V 1" Storm = 0.68 FPS
Z Right = 3 :1 (avg between culverts) Q 10 year = 3.03 cfs
Avg.S=l 0.005000 IftIft (avg. slope) W = 6.54 FT
V 10 = 2.07 IFPS
T= Shear Stress Y= 62.4 PCF
T= 0.028 PSF d= 0.09 FT
S= 0.01 FT/FT
RECOMMENDED LINING: Seed and Mulch With Contractor's Blend
CHECK 1" STORM EVENT
HYDRAULIC RETENTION TIME:
Q 1" Storm = 0.39 cfs
Swale Length =
If
Available Depth (With 6"
EEft
Freeboard)=
Total Swale Depth = 1
ft
TERMINOLOGY:
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)
Side Slope = 3.00 :1
Swale Capacity at
Available Depth = 75.00 cf
Hydraulic Retention = 3.24 minutes
CHANNEL LINING:
With velocities less than 2 f/s use Seed and Mulching
With velocites greater than 2 f/s use Temporary Ditch Liner
: if T < I then use Coir Wattle against silt fence
: if T > I then use other lining
A= Cross -Sectional Area of Flow, (FT^2)
P = Wetted Perimeter of the Flow, (FT)
R = Hydraulic Radius, (FT)
S = Slope of the Channel, (FT/FT)
Q = Discharge,(CFS)
V= Velocity, (FPS)
W = Top Width of Water in Channel, (FT)
Y = Specific Weight of Water (62.4 PCF)
OBJECTIVE:
SOLUTIONS:
RUNOFF CONDITIONS
MAXIMUM
Slope Condition
SHEAR STRESS:
CONVEYANCE AND TEMPORARY DIVERSION SWALE 7
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 F5.81 7.97
Q 1" Event = 2.32 cfs
Q 10 year event= 18.52 cfs
d = 0.220 ft (min. flow depth for 1"storm) A = 1.47 FT^2
d = 0.7 ft (for 10 year storm event) P = 7.39 FT
n = 0.030 (computed) R = 0.20
8 = 6 ft (min. width) Q 1" Storm = 2.47 CFS
Z Left = 3 :1 (avg between culverts) V 1" Storm = 1.69 FPS
Z Right = 3 :1 (avg between culverts) Q 10 year = 18.76 cfs
Avg.S=l 0.010000 IftIft (avg. slope) W = 7.32 FT
V 10 = 3.31 FPS
T= Shear Stress Y= 62.4 PCF
T= 0.137 PSF d= 0.22 FT
S= 0.01 FT/FT
RECOMMENDED LINING: Seed and Mulch With Contractor's Blend
CHECK 1" STORM EVENT
HYDRAULIC RETENTION TIME:
Q 1" Storm = 2.47 cfs
Swale Length =EEft
If
Available Depth (With 6"
Freeboard)=
Total Swale Depth = 1
ft
TERMINOLOGY:
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)
Side Slope = 3.00 :1
Swale Capacity at
Available Depth = 431.25 cf
Hydraulic Retention = 2.91 minutes
CHANNEL LINING:
With velocities less than 2 f/s use Seed and Mulching
With velocites greater than 2 f/s use Temporary Ditch Liner
: if T < I then use Coir Wattle against silt fence
: if T > I then use other lining
A= Cross -Sectional Area of Flow, (FT^2)
P = Wetted Perimeter of the Flow, (FT)
R = Hydraulic Radius, (FT)
S = Slope of the Channel, (FT/FT)
Q = Discharge,(CFS)
V= Velocity, (FPS)
W = Top Width of Water in Channel, (FT)
Y = Specific Weight of Water (62.4 PCF)
OBJECTIVE:
SOLUTIONS:
RUNOFF CONDITIONS
MAXIMUM
Slope Condition
SHEAR STRESS:
CONVEYANCE AND TEMPORARY DIVERSION SWALE 8A & 813
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 F4.89 7.97
Q 1" Event = 1.96 cfs
Q 10 year event= 15.59 cfs
d = 0.310 ft (min. flow depth for 1"storm) A = 2.15 FT^2
d = 0.9$ ft (for 10 year storm event) P = 7.96 FT
n = 0.030 (computed) R = 0.27
8 = 6 ft (min. width) Q 1" Storm = 1.99 CFS
Z Left = 3 :1 (avg between culverts) V 1" Storm = 0.93 FPS
Z Right = 3 :1 (avg between culverts) Q 10 year = 15.61 cfs
Avg.S=l 0.002000 IftIft (avg. slope) W = 7.86 FT
V 10 = 1.78 IFPS
T= Shear Stress Y= 62.4 PCF
T= 0.039 PSF d= 0.31 FT
S= 0.00 FT/FT
RECOMMENDED LINING: Seed and Mulch With Contractor's Blend
CHECK 1" STORM EVENT
HYDRAULIC RETENTION TIME:
Q 1" Storm = 1.99 cfs
Swale Length =
If
Available Depth (With 6"
EEft
Freeboard)=
Total Swale Depth = 1
ft
TERMINOLOGY:
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)
Side Slope = 3.00 :1
Swale Capacity at
Available Depth = 356.25 cf
Hydraulic Retention = 2.98 minutes
CHANNEL LINING:
With velocities less than 2 f/s use Seed and Mulching
With velocites greater than 2 f/s use Temporary Ditch Liner
: if T < I then use Coir Wattle against silt fence
: if T > I then use other lining
A= Cross -Sectional Area of Flow, (FT^2)
P = Wetted Perimeter of the Flow, (FT)
R = Hydraulic Radius, (FT)
S = Slope of the Channel, (FT/FT)
Q = Discharge,(CFS)
V= Velocity, (FPS)
W = Top Width of Water in Channel, (FT)
Y = Specific Weight of Water (62.4 PCF)
OBJECTIVE:
SOLUTIONS:
RUNOFF CONDITIONS
MAXIMUM
Slope Condition
SHEAR STRESS:
CONVEYANCE AND TEMPORARY DIVERSION SWALE 9A & 9B
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 FO.54 7.97
Q 1" Event = 0.22 cfs
Q 10 year event= 1.72 cfs
d = 0.052 ft (min. flow depth for 1"storm) A = 0.32 FT^2
d = 0.18 ft (for 10 year storm event) P = 6.33 FT
n = 0.030 (computed) R = 0.05
8 = 6 ft (min. width) Q 1" Storm = 0.22 CFS
Z Left = 3 :1 (avg between culverts) V 1" Storm = 0.68 FPS
Z Right = 3 :1 (avg between culverts) Q 10 year = 1.76 cfs
Avg.S=l 0.010000 IftIft (avg. slope) W = 6.31 FT
V 10 = 1.49 FPS
T= Shear Stress Y= 62.4 PCF
T= 0.032 PSF d= 0.05 FT
S= 0.01 FT/FT
RECOMMENDED LINING: Seed and Mulch With Contractor's Blend
CHECK 1" STORM EVENT
HYDRAULIC RETENTION TIME:
Q 1" Storm = 0.22 cfs
Swale Length =
If
Available Depth (With 6"
EEft
Freeboard)=
Total Swale Depth = 1
ft
TERMINOLOGY:
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)
Side Slope = 3.00 :1
Swale Capacity at
Available Depth = 56.25 cf
Hydraulic Retention = 4.31 minutes
CHANNEL LINING:
With velocities less than 2 f/s use Seed and Mulching
With velocites greater than 2 f/s use Temporary Ditch Liner
: if T < I then use Coir Wattle against silt fence
: if T > I then use other lining
A= Cross -Sectional Area of Flow, (FT^2)
P = Wetted Perimeter of the Flow, (FT)
R = Hydraulic Radius, (FT)
S = Slope of the Channel, (FT/FT)
Q = Discharge,(CFS)
V= Velocity, (FPS)
W = Top Width of Water in Channel, (FT)
Y = Specific Weight of Water (62.4 PCF)
TEMPORARY SEDIMENT TRAPS
McPhail Meadows
TEMPORARY SEDIMENT TRAP01
Design Storm Event Return Interval/Duration:
10
year
�5 min.
Post Watershed Size:
4.89
acres
Disturbed Area:
3.83
acres
Peak Discharge Rainfall Intensity:
7.970
in/hr
Pre -Development c:
0.2
unimproved area
Post -Development c:
0.4
residential -single family Q pre: 7.79 cfs
Estimated Percent Impervious Area:
24
%
Q post: 15.59 cfs
Impervious Area:
1.174
acres
Pervious Area:
3.716
acres
Minimum Volume Requirement:
3,600
cf/acre of disturbed
area
Minimum Volume Required:
13,788
cf
Minimum Surface Area Requirement:
435
sf/cfs of Q10
peak flow
Minimum Surface Area Requirement:
6,781
sf
Basin Sizing
Top of Dam Elevation:
236.00
ft
Depth of Sediment Storage Above Grade: 2.00
ft
Crest of Spillway Elevation:
234.50
ft
Meets Minimum 2' Storage Depth Above Grade
Existing Grade:
232.50
ft
Basin Bottom Length:
250.00
ft
Basin Bottom Width:
6.50
ft
Meets Minimum 2:1 L/W Ratio
Excavation Depth Below Grade:
1.50
ft
Meets Minimum Excavation Depth Below Grade
Basin Width At Crest Elevation of Stone Spillway Outlet:
27.50
ft
Side Slopes of Basin: 3.00
: 1
Surface Area At Crest Elevation of Spillway Outlet:
I
sf
Meets Minimum Surface Area Requirements
Bottom of Basin Elevation:
231.00
ft
Surface Area of Basin Bottom:
1,625
sf
Depth of Available Storage Below Crest of Spillway Outlet:
3.50
ft
Available Storage Volume at Crest of Spillway Outlet:
14,875
cf
Meets Minimum Volume Requirements
Noff
Spillway Design
Qpeak:
15.59
cfs
Depth of Flow Across Weir:
0.50
ft
Meets Maximum 'Recommended' Flow Depth
Weir Length:
15.00
ft
Flow Capacity Across Weir:
15.91
cfs
Meets Flow Capacity Requirement
Spillway Crest Elevation:
234.50
ft
Top of Dam Elevation:
236.00
ft
Freeboard Provided:
1.00
ft
Meets Minimum 'Recommended' Freeboard
Sediment Cleanout Elevation:
232.75
ft
Mark this elevation in the field
McPhail Meadows
Design Storm Event ReturnInterval/Duration:
10
year F5 min.
Post Watershed Size:
2.45
acres
Disturbed Area:
2.13
acres
Peak Discharge Rainfall Intensity:
7.970
in/hr
Pre -Development c:
0.2
unimproved area
Post -Development c:
0.4
residential -single family
Estimated Percent Impervious Area:
24
I mpervious Area:
0.588
acres
Pervious Area:
1.862
acres
Minimum Volume Requirement:
3,600
cf/acre of disturbed area
Minimum Volume Required:
7,668
cf
Minimum Surface Area Requirement:
435
sf/cfs of Q10 peak flow
Minimum Surface Area Requirement:
3,398
sf
Basin
Top of Dam Elevation: 234.50 ft
Depth of Sediment Storage Above Grade: 2.00 ft
Crest of Spillway Elevation:
233.00 ft
Existing Grade:M15
ft
Basin Bottom Length:ft
Basin Bottom Width:ft
Excavation Depth Below Grade:ft
Basin Width At CrestElevation of Stone Spillway Outlet:
25.50 ft
Side Slopes of Basin:
3.00 : 1
Surface Area At Crest Elevation of Spillway Outlet:
3,h_. sf
Bottom of Basin Elevation:
229.50 ft
Surface Area of Basin Bottom:
0,675 sf
Depth of Available Storage Below Crest of Spillway Outlet:
3.50 ft
Available Storage Volume at Crest of Spillway Outlet:
' oT- cf
Qpeak: 7.81 cfs
Depth of Flow Across Weir: 0.50 ft
Weir Length:1 8.00 Ift
Flow Capacity Across Weir: 8.49 cfs
Spillway Crest Elevation: 233.00 ft
Top of Dam Elevation: 234.50 ft
Freeboard Provided: 1.00 ft
Sediment Cleanout Elevation: 231.25 ft
TEMPORARY SEDIMENT TRAP 02
Q pre: 3.91 cfs
Q post: 7.81 cfs
Meets Minimum 2' Storage Depth Above Grade
Meets Minimum 2:1 L/W Ratio
Meets Minimum Excavation Depth Below Grade
Meets Minimum Surface Area Requirements
Meets Minimum Volume Requirements
Meets Maximum 'Recommended' Flow Depth
Meets Flow Capacity Requirement
Meets Minimum 'Recommended'Freeboard
Mark this elevation in the field
McPhail Meadows
TEMPORARY SEDIMENT TRAP 03
Design Storm Event Return Interval/Duration:
10
year F5 min.
Post Watershed Size:
3.96
acres
Disturbed Area:
3.77
acres
Peak Discharge Rainfall Intensity:
7.970
in/hr
Pre -Development c:
0.2
unimproved area
Post -Development c:
0.4
residential -single family Q pre: 6.31 cfs
Estimated Percent Impervious Area:
1 24
% Q post: 12.62 cfs
Impervious Area:
0.950
acres
Pervious Area:
3.010
acres
Minimum Volume Requirement:
3,600
cf/acre of disturbed area
Minimum Volume Required:
13,572
cf
Minimum Surface Area Requirement:
435
sf/cfs of Q10 peak flow
Minimum Surface Area Requirement:
5,492
sf
Basin Sizin
Top of Dam Elevation: 227.50 ft
Depth of Sediment Storage Above Grade: 2.00 ft
Crest of Spillway Elevation:
226.00
ft
Meets Minimum 2'Storage Depth Above Grade
Existing Grade:
224.00
ft
Basin Bottom Length:
285.00
ft
Basin Bottom Width:
4.00
ft
Meets Minimum 2:1 L/W Ratio
Excavation Depth Below Grade:
1.50
ft
Meets Minimum Excavation Depth Below Grade
Basin Width At Crest Elevation of Stone Spillway Outlet:
25.00
ft
Side Slopes of Basin:
3.00 : 1
Surface Area At Crest Elevation of Spillway Outlet:
7,125
sf
Meets Minimum Surface Area Requirements
Bottom of Basin Elevation:
222.50
ft
Surface Area of Basin Bottom:
1,140
sf
Depth of Available Storage Below Crest of Spillway Outlet:
3.50
ft
Available Storage Volume at Crest of Spillway Outlet:
14,464
cf
Meets Minimum Volume Requirements
Qpeak:
12.62 cfs
Depth of Flow Across Weir:
0.50 ft
Weir Length:
12.00 ft
Flow Capacity Across Weir:
12.73 cfs
Spillway Crest Elevation:
226.00 ft
Top of Dam Elevation:
227.50 ft
Freeboard Provided:
1.00 ft
Sediment Cleanout Elevation: 224.25
Meets Maximum 'Recommended' Flow Depth
Meets Flow Capacity Requirement
Meets Minimum 'Recommended' Freeboard
Mark this elevation in the field
McPhail Meadows
TEMPORARY SEDIMENT TRAP 04
Design Storm Event Return Interval/Duration:
10
year F5 min.
Post Watershed Size:
4.75
acres
Disturbed Area:
4.2
acres
Peak Discharge Rainfall Intensity:
7.970
in/hr
Pre -Development c:
0.2
unimproved area
Post -Development c:
0.4
residential -single family Q pre: 7.57 cfs
Estimated Percent Impervious Area:
1 24
% Q post: 15.14 cfs
Impervious Area:
1.140
acres
Pervious Area:
3.610
acres
Minimum Volume Requirement:
3,600
cf/acre of disturbed area
Minimum Volume Required:
15,120
cf
Minimum Surface Area Requirement:
435
sf/cfs of Q10 peak flow
Minimum Surface Area Requirement:
6,587
sf
Basin Sizin
Top of Dam Elevation: 231.50 ft
Depth of Sediment Storage Above Grade: 2.00 ft
Crest of Spillway Elevation:
230.00
ft
Meets Minimum 2'Storage Depth Above Grade
Existing Grade:
228.00
ft
Basin Bottom Length:
115.00
ft
Basin Bottom Width:
45.00
ft
Meets Minimum 2:1 L/W Ratio
Excavation Depth Below Grade:
1.50
ft
Meets Minimum Excavation Depth Below Grade
Basin Width At Crest Elevation of Stone Spillway Outlet:
59.00
ft
Side Slopes of Basin:
2.00 : 1
Surface Area At Crest Elevation of Spillway Outlet:
6,785
sf
Meets Minimum Surface Area Requirements
Bottom of Basin Elevation:
226.50
ft
Surface Area of Basin Bottom:
5,175
sf
Depth of Available Storage Below Crest of Spillway Outlet:
3.50
ft
Available Storage Volume at Crest of Spillway Outlet:
20,930
cf
Meets Minimum Volume Requirements
Qpeak:
15.14 cfs
Depth of Flow Across Weir:
0.50 ft
Weir Length:
15.00 ft
Flow Capacity Across Weir:
15.91 cfs
Spillway Crest Elevation:
230.00 ft
Top of Dam Elevation:
231.50 ft
Freeboard Provided:
1.00 ft
Sediment Cleanout Elevation: 228.25
Meets Maximum 'Recommended' Flow Depth
Meets Flow Capacity Requirement
Meets Minimum 'Recommended' Freeboard
Mark this elevation in the field