20080845 Ver 1_Stormwater Info_20080602

Stormwater Impact Analysis -
Construction Drawing Submittal to DWQ
For the proposed
White Deer Park
Garner, North Carolina
Prepared for
OBS Landscape Architects Land Planners
Prepared By
Stewart Engineering, Inc.
%aww",
STEWART
March 20, 2008
Revised April 28, 2008
Revised May 30, 2008
pdC? D
o ? ??pR
JUN ??E?c«???R
was ?os?oR?P
v+?
Stormwater Impact Analysis
For
White Deer Park
Garner, North Carolina
Prepared for:
OBS Landscape Architects Land Planners
Prepared by:
Stewart Engineering, Inc.
421 Fayetteville Street, Suite 400
Raleigh, NC 27601
919.380.8750
4
SEAL
- 0 OW317 Z
"8111 lots%%
PRELIMINARY - FOR REVIEW
PURPOSES ONLY
Stewart Project No. C7005
March 20, 2008
Revised April 28, 2008
Revised May 30, 2008
Stormwater Impact Analysis
WHITE DEER PARK
GARNER, NORTH CAROLINA
EXECUTIVE SUMMARY
This Stormwater Impact Analysis has been prepared specifically to address
the requirements of the Town of Garner Stormwater Management Ordinance
(Article 7, Section 7.2 of the Unified Development Ordinance), in order to quantify
the impact of the proposed development upon downstream systems. Per the Town
of Garner Stormwater Management Ordinance, the post-development peak flow
rate for the 1-, 10-, 25-year, 24-hour storm events must be held to that of pre-
development conditions. The Total Nitrogen Export for the site must also be held to
3.6 lb/ac/yr.
As is detailed below, the post-development peak flow rate in each storm of
interest remains equal to that of the per-development condition due to the large
overall drainage basin (1304.71 ac). The pre-development Total Nitrogen Export is
calculated as 2.17 Ib/ac/yr where as the post-development is to 2.16 lb/ac/yr.
Given that the post-development export is less than 3.6 Ib/ac/yr without the use of
BMPs, no buydown payment will be required for this project.
Site Information
The White Deer Park site is located at the intersection of Buffaloe and
Aversboro Roads in Garner. The existing site is mostly wooded but does include
two substantial open areas. The project site is located in the southeast corner of a
91.41 ac parcel with a project area of approximately 25.50 ac. Existing impervious
area on the site is 0.38 ac.
The site lies within the Neuse River Basin along with the Lake Benson
Conservation District. Per FEMA FIRMs 3720170001 and 37201710003, the site
contains a 100-yr floodplain associated with a tributary to Reedy Creek. The Wake
County Soil Survey Map indicates the soils on site consist primarily of Cecil sandy
loams which are classified as Hydrologic Soil Group B. The project area also
contains two existing intermittent streams, one of which runs long the northwest
boundary of the project area and one that splits the project area from west to east.
Both stream corridors will be protected with 50' Neuse River Buffers. Portions of
each stream are also buffered with a 90' Lake Benson Watershed Conservation
Buffer.
Proposed Improvements
The proposed development on the site will include a nature center (2500 sf),
restrooms, learning terrace, picnic shelters, playground areas, entry drive, site
roads, and parking lots. The site improvements will add 4.02 ac of additional
impervious area for a total proposed impervious area of 4.40 ac or 4.81% (based
upon parcel area).
Stormwater from the majority of the proposed parking areas will be captured
and treated in one of four bioretention areas. Each bioretention area has been
sized to capture the portion of parking area which drains to it and is equipped with
underdrains. As is described in the Design Procedure and Overall Results portions
of this report, these BMPs are not required to meet either the Peak Flow or Nitrogen
Export portions of the Town of Garner Stormwater Management Ordinance.
Design Procedure
The analysis point for the Peak Flow Analysis portion of the report is taken as
the point where drainage from the project area leaves the site. This point happens
to be the point at which the tributary to Reedy Creek existing the parcel (along the
southwestern property boundary). The total drainage area (including offsite areas)
to this point is approximately 1305 ac. The peak flow at this point is determined by
using the SCS Hydrograph Formulation Method. The cover conditions for the
project area is based upon the actual site conditions where as the offsite areas are
based upon their current zoning. The Time of Concentration for the drainage area
is determined using the method outlined in USDA TR-55.
Due to the fact that the overall drainage area is significantly large in
comparison to the project area, the increase in impervious area caused by
development of the site does not increase the Curve Number. The Time of
Concentration remains the same as well. Therefore, there is no increase in peak
flow at the point of discharge off the site.
The pre- and post-development Total Nitrogen Export is calculated for the
parcel area using the Town of Garner worksheet.
Overall Results
The results from the peak flow analysis and Total Nitrogen Export
calculations are below. Note that the peak flow analysis is based upon the overall
drainage area and associated cover conditions where as the Total Nitrogen Export
calculations are based upon the parcel area. Please see the corresponding
appendices for detailed calculations.
Peak Flow Analysis
The table below shows the pre- and post-development peak flow for the 1-,
10-, and 25-year, 24-hour storm events. As is shown, the peak flow in the post-
development condition is equal to that of the pre-development condition for each
storm event.
Peak Flow Analysis
1-yr 10-yr 25-yr
Drainage Curve Peak Percent Peak Percent Peak Percent
Area Number Flow Increase Flow Increase Flow Increase
ac cfs cfs cfs
Existing 91.41 70 261.83 974.10 1416.41
Proposed 91.41 70 261.83 0.00% 974.10 0.00% 1416.41 0.00%
Total Nitrogen Export
The pre-development Total Nitrogen Export for the parcel (91.41 ac) is 2.17
Ib/ac/yr with a post-development export of 2.16 lb/ac/yr. This is below the
allowable export of 3.6 lb/ac/yr.
Diffuse Flow Narrative
As stated above the project does not require mitigation of stormwater quality
or quantity, but due to the type of project (environmental education park) the Town
of Garner is installing Bio-retention ponds for the parking area increase in
impervious. These ponds will outfall as shown on the plans through rip rap and due
to the low flow and length to the buffer there is sufficient diffused flow from these
outfalls to not require level spreaders. (see table below).
Outlet 10 r storm velocity (fps) Distance to Channel
FES 3 (Bio-retention ponds 4.4 190' of natural woods
A & B sloped @ 8.9%
FES 4 (Bio-retention ponds 3.2 210' of natural woods
C & D) sloped @ 8%
Conclusions
Based upon the results of this analysis shown above, the requirements Town
of Garner Stormwater Management Ordinance as it pertains to Peak Flow and Total
Nitrogen Export have been met for this project with no structural measures.
TopoZone - USES Lake Wheeler (NC) Topo Map
topozone
?M3Fr`. a}a1'
u ?° l f p
? -yam ? $

S 4
a k
? H ? n

k

s
SITE
4 ?

N A D

s f 9

Page 1 of 1
M*
G
UTM 17 714799E 3950728N (NAD83/WGS84)
USGS Lake Wheeler (NC) Quadrangle pq-_8.795
Projection is UTM Zone 17 NAD83 Datum G=1.385
http://www.topozone.com/print.asp?lat=35.67708&lon=-78.62658&s=24&size=l&u=4&layer=DRG25&d... 3/18/2008

- v
n
0
r
Z
D
N
mm
m
z
c
z
co
m
M
00
rn

fw?
0., 2009 1000 1 Miie
p
Z
? ? 5000 Feet
? .+ 1 1 5 3.
.Y.?-?1 .,J..h (I t77)
N

? ?i1
?
x,j)
0
kF ???1
;9 ?H •
z?
F '?M
w\?
I
'?
?
/ ?????
? ??. ,1??`
`
?
? .
?
r
?
? \
F
1 _
?
S
? ?
r.?'
?
kt ?y.??
?,
??
a
y y -

?.a
b
`
? rJ. 'k.\t} '*?r il,?fl s; ? 4 aia ? ?. . .
?? icy s ?• >;,+--•roY` e'?]i„'
w
s
. ,?t
'fix"
cC ?x

t

ak
7
S
-. t\~ a y,x-i
/?.?5 ? + f
y,7rM°}a;
? "?i7 ?+i ?{ l6tl
-

•?? l
Ff f"r'%`?'
fi"` r ?
{ ?'? ? ? " k
J
t+ *f? 0r????7N?
?„ ? *f e?"?
A"Fh f
es?
.
9 y
`
v'e

?d}?+,?$ -..>
??
?

'sJ?3at ?? ?ak
??
ia
?3 ?,?? J'y„s+ ?`? ? Jf 'td? ?? ? ?
a , a r. 1 >rws_

? Ili •,
F
?sr9+. { ?JI' r .1A??????kr?x 4??A
r?,k?t?.v?,?? 1 y.{, x?'F^'w ,t. x,•fy '•? tA.

?.;A

.i

YC ffi
'[ ,?' 'n? 6 N

2

r.
x•41. nN C - 'b' _
m
? m
x
c {? +f C
r 8

a•
CD
S

r ..
VSf ?
a
1 k?
r dW 7

Tt- }.k? ?.te.xr.?' •.Fz-`: ?.: '

r
y ,y
l s'?m
.xy,}met, I 4

a
.f
o ?
?a> ago:.,... _e . _? - _ - ... f
-'•

.
(loins st eet 78)
-?°'Ii N'?III?191Pi'1?191h1@?1
it i

CO o w 1 ?cl M
N
.r ..Vi N 0 ?? 00 M
Appendix 1
Peak Flow Analysis - 1- 10-, & 25-year Storm Events
(based upon total drainage area)
Cover
I
Area
sf)
Area
(ac)
CN
Impervious
Bldg 0 0.00
Road 6559 0.15
Sidewalk 0 0.00
Total Imp 16386 0.38 98
Open 619859 14.23 69
Wooded 3345477 76.80 60
IWIriL JVDA/ZZ y1.41 b/
Zoning Area
(sf Area
(ac) CN
R-12 50809010 1166.41 70
R-40 2042379 46.89 85

IUTAL 52S51389 1213.30 71
PROPOSED DRAINAGE AREA - PARCEL PROPOSED DRAINAGE AREA - OFFSITE
Cover Area
sf Area
(ac) CN
Impervious
Bldg 11776 0.27
Parkin 95051 2.18
Sidewalk 85025 1.95
Total Imp 191852 4.40 98
Open 536177 12.31 69
Wooded 3253693 74.69 60
JVDA/zz V1.41 b3
Zoning Area
sf Area
ac CN
R-12 50809010 1166.41 70
R-40 2042379 46.89 85

I V I AL Sttf513tf9 1L13.3U /1
421 Fayetteville St., Suite 400, Raleigh, NC 27601 Tel [phone] Fax [phone] www.stewart-eng.com
• TR55 Tc Worksheet
Hydraflow Hydrographs by Intelisolve
Hyd. No. 1
Total Existing
Description A B C Totals
Sheet Flow
Manning's n-value = 0.011 0.011 0.011
Flow length (ft) = 100.0 0.0 0.0
Two-year 24-hr precip. (in) = 3.60 0.00 0.00
Land slope (%) = 2.70 0.00 0.00
Travel Time (min) = 1.01 + 0.00 + 0.00 _ 1.01
Shallow Concentrated Flow
Flow length (ft) = 1526.00 0.00 0.00
Watercourse slope (%) = 2.12 0.00 0.00
Surface description = Unpaved Paved Paved
Average velocity (ft/s) = 2.35 0.00 0.00
Travel Time (min) = 10.83 + 0.00 + 0.00 = 10.83
Channel Flow
X sectional flow area (sgft) = 63.00 0.00 0.00
Wetted perimeter (ft) = 32.00 0.00 0.00
Channel slope (%) = 0.78 0.00 0.00 ;
Manning's n-value = 0.080 0.015 0.015
Velocity (ft/s) = 2.59 0.00 0.00
Flow length (ft) = 13868.0 0.0 0.0
Travel Time (min) = 89.25 + 0.00 + 0.00 = 89.25
Total Travel Time, Tc ....................................... ........................ .............. 101.10 min
TR55 Tc Worksheet
Hydraflow Hydrographs by Intelisolve
Hyd. No. 2
Total Proposed
Description A B C Totals
Sheet Flow
Manning's n-value = 0.011 0.011 0.011
Flow length (ft) - 100.0 0.0 0.0
Two-year 24-hr precip. (in) = 3.60 0.00 0.00
Land slope (%) = 2.70 0.00 0.00
Travel Time (min) _ 1.01 + 0.00 + 0.00 = 1.01
Shallow Concentrated Flow -
Flow length (ft) = 1526.00 0.00 0.00
Watercourse slope (%°) = 2.12 0.00 0.00
Surface description = Unpaved Paved Paved
Average velocity (ft/s) = 2.35 0.00 0.00
Travel Time (min) _ 10.83 + 0.00 + 0.00 _ 10.83
Channel Flow
X sectional flow area (sqft) = 63.00 0.00 0.00
Wetted perimeter (ft) = 32.00 0.00 0.00
Channel slope (%) = 0.78 0.00 0.00
Manning's n-value = 0.080 0.015 0.015
Velocity (ft/s) = 2.59 0.00 0.00
Flow length (ft) = 13868.0 0.0 0.0
Travel Time (min) = 89.25 + 0.00 + 0.00 = 89.25
Total Travel Time, Tc ................ ................................................ .............. 101.10 min
Hydrograph Return Period Recap
Hyd.
No Hydrograph
t
e Inflow
H
d Peak Outflow (cfs) Hydrograph
. yp

(origin) y
(s)

1-Yr

2-Yr

3-Yr

5-Yr

10-Yr

25-Yr

50-Yr

100-Yr
description
1
2 SCS Runoff -----
SCS Runoff ------- 261.83
261.83 -------
------- -------
------- -------
------- 974.10
974.10 1416.41
1416.40 -------
------- ------
------- Total Existing
Total Proposed
Proj. file: 2008.03.19-C7005.gpw Thursday, Mar 20 2008,10:14 AM
Hydraflow Hydrographs by Intelisolve
Hydrograph Summary Report
Hyd.
No. Hydrograph
type
(origin) Peak
flow
(cfs) Time
interval
(min) Time to
peak
(min) Volume

(cult) Inflow
hyd(s) Maximum
elevation
(ft) Maximum Hydrograph
storage description
(cult)
1 SCS Runoff 261.83 10 790 3,443,235 --- ------ ------ Total Existing
2 SCS Runoff 261.83 10 790 3,443,208 ---- ------ ------ Total Proposed
2008.03.19-C7005.gpw Return Period: 1 Year Thursday, Mar 20 2008, 10:14 AM
Hydraflow Hydrographs by Intelisolve
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve Thursday, Mar 20 2008,10:14 AM
Hyd. No. 1
Total Existing
Hydrograph type = SCS Runoff Peak discharge = 261.83 cfs
Storm frequency = 1 yrs Time interval = 10 min
Drainage area = 1304.700 ac Curve number = 70
Basin Slope = 0.0% Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 101.10 min
Total precip. = 3.00 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
Hydrograph Volume = 3,443,235 cuft
Q (cfs) Total Existing
Hyd. No. 1 -- 1 Yr Q (cfs)
280.00
240.00
200.00
160.00
120.00
80.00
40.00
280.00
240.00
200.00
160.00
120.00
80.00
40.00
0.00 I I I t 1 1 I 1 ? 0.00
0 3 7 10 13 17 20 23 27
Hyd No. 1 Time (hrs)
• Hydrograph Plot
Hydraflow Hydrographs by Intelisolve Thursday, Mar 20 2008, 10:14 AM
Hyd. No. 2
Total Proposed
Hydrograph type = SCS Runoff Peak discharge = 261.83 cfs
Storm frequency = 1 yrs ` Time interval = 10 min
Drainage area = 1304.690 ac Curve number = 70
Basin Slope = 0.0% Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 101.10 min
Total precip. = 3.00 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
Q (cfs) Total Proposed
Hyd. No. 2 -- 1 Yr
280.00
240.00
200.00.
160.00
120.00
80.00
40.00
280.00
240.00
200.00
160.00
120.00
80.00
40.00
0.00 1 I I I I I I I -"<Q 0.00
0 3 7 10 13 17 20 23 27
Time (hrs)
Hyd No. 2
Hydrograph Volume = 3,443,208 cuft
Q (cfs)
Hydrograph Summary Report
Hyd.
No. Hydrograph Peak
type flow
(origin) (cfs) Time
interval
(min) Time to
peak
(min) Volume

(cult) Inflow
hyd(s) Maximum
elevation
(ft) Maximum
storage
(cuft) Hydrograph
description
1 SCS Runoff 974.10 10 780 10,828,350 ---- ------ ------ Total Existing
2 SCS Runoff 974.10 10 780 10,828,270 ---- ------ ------ Total Proposed
2008.03.19-C7005.gpw Return Period: 10 Year Thursday, Mar 20 2008, 10:14 AM
Hydraflow Hydrographs by Intelisolve
Hydrograph Plot_
Hydraflow Hydrographs by Intelisolve
Hyd. No. 1
Total Existing
Hydrograph type = SCS Runoff
Storm frequency = 10 yrs
Drainage area = 1304.700 ac
Basin Slope = 0.0%
Tc method = TR55
Total precip. = 5.28 in
Storm duration = 24 hrs
Thursday, Mar 20 2008, 10:14 AM
Peak discharge = 974.10 cfs
Time interval = 10 min
Curve number = 70
Hydraulic length = oft
Time of conc. (Tc) = 101.10 min
Distribution = Type II
Shape factor = 484
Q (cfs)
980.00
840.00
............... .................. .
700.00
.........
560.00
.................................................
................. _
..................:............
..........
420.00
.................................................
280.00
140.00
.................................................
0.00
Hydrograph Volume = 10,828,350 cuft
Total Existing
Hyd. No. 1 -- 10 Yr Q (cfs)
980.00
.......... ..........
840.00
............ _? ...
700.00
560.00
420.00
280.00
140.00
n nn
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 2
Total Proposed
Hydrograph type = SCS Runoff
Storm frequency = 10 yrs
Drainage area = 1304.690 ac
Basin Slope = 0.0%
Tc method = TR55
Total precip. = 5.28 in
Storm duration = 24 hrs
Thursday, Mar 20 2008, 10:14 AM
Peak discharge = 974.10 cfs
Time interval = 10 min
Curve number = 70
Hydraulic length = 0 ft
Time of conc. (Tc) = 101.10 min
Distribution = Type II
Shape factor = 484
Q (cfs)
980.00
840.00
Hydrograph Volume = 10,828,270 cuft
Total Proposed
Hyd. No. 2 - 10 Yr
700.00
560.00
420.00
280.00
Q (cfs)
980.00
840.00
700.00
560.00
420.00
280.00
140.00
140.00
Hydrograph Summary Report
Hyd.
No. Hydrograph
type
(origin) Peak
flow
(cfs) _ Time
interval
(min) Time to
peak
(min) Volume

(cult) Inflow
hyd(s) Maximum
elevation
(ft) Maximum
storage
(cult) Hydrograph
description
1 SCS Runoff 1416.41 10 .780 15,381,800 ---- ------ ----- Total Existing
2 SCS Runoff 1416.40 10 780 15,381,680 ---- ------ ------ Total Proposed
2008.03.19-C7005.gpw Return Period: 25 Year Thursday, Mar 20 2008,10:14 AM
Hydraflow Hydrographs by Intelisolve
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve Thursday, Mar 20 2008, 10:15 AM
Hyd. No. 1
Total Existing
Hydrograph type = SCS Runoff Peak discharge ` = 1416.41 cfs
Storm frequency = 25 yrs Time interval = 10 min
Drainage area = 1304.700 ac " Curve number = 70
Basin Slope = 0.0% Hydraulic length = Oft
Tc method = TR55 Time of conc. (Tc) = 101.10 min
Total precip. = 6.48 in Distribution = Type II
Storm duration = 24 firs Shape factor = 484
Hydrograph Volume = 15,381,800 cuft
Total Existing
Q (cfs) Hyd. No. 1 -- 25 Yr Q (cfs)
1421 00
1218.00
1015.00
812.00
609.00
406.00
203.00
0.00

1421.00
1218.00
1015.00
812.00
609.00
406.00
203.00
n nn
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 2
Total Proposed
Hydrograph type = SCS Runoff
Storm frequency = 25 yrs
Drainage area = 1304.690 ac
Basin Slope = 0.0%
Tc method = TR55
Total precip. = 6.48 in
Storm duration = 24 hrs
Thursday, Mar 20 2008,10:15 AM
Peak discharge = 1416.40 cfs
Time interval = 10 min
Curve number = 70
Hydraulic length = Oft
Time of conc. (Tc) = 101.10 min
Distribution = Type II
Shape factor = 484
Total Proposed
Q (cfs)
Hyd. No. 2 -- 25 Yr
1421.00

1218.00
Hydrograph Volume = 15,381,680 cuft
Q (cfs)
7F7T
1015.00
812.00
609.00
406.00
203.00
1421.00
1218.00
1015.00
812.00
609.00
406.00
203.00
0.00 1"",- I I I ._ _. _ I-- - I _ n nn

STEWARD
Site Data Analysis - Nitrogen Calculations
(Based upon total Parcel Area)
Existing Conditions
Existing forest land 76.80 ac
Existing pasture 14.23 ac
Existing residential 0.00 ac
Existing cropland 0.00 ac
Existing commercial/industrial 0.38 ac
Total Project Area 91.41 ac
Proposed Conditions
Protected Open 0.00 ac
Managed Open 87.01 ac
Impervious 4.40 ac
Total Project Area 91.41 ac
k z E
=r STEWART
Existing Nitrogen Runoff Calculations
Total Parcel
Step 1: Determine area for each type of land use and enter in Column (2):
Step 2: Total the areas for each type of land use and enter at the bottom of Column (2).
Step 3: Multiply the areas in Column (2) by the TN export Coefficients in Column (3) and enter
in Column (4).
Step 4: Total the TN exports for each type of land use and enter at the bottom of Column (4).
Step 5: Determine the export coefficient for site by dividing the total TN export from uses at the
bottom of Column (4) by the area at the bottom of Column (2).
(1)
Type of Land Cover (2)
Areas (3)
TN export coefficient (4)
TN export from use
(acres) (lbs/ac/yr) (lbs/yr)
Existing forest land
Existing pasture
Existing residential
Existing cropland
Existing commercial/industrial 76.800
14.230
0.000
0,000
0.380 1.70
4.40
7.50
13.6
13 130.560
62.612
0.000
0.000
4.940

TOTAL 91.410 --- 198.112

STEWART
Proposed Nitrogen Runoff Calculations
Total Parcel
Step 1: Determine area for each type of land use and enter in Column (2).
Step 2: Total the areas for each type of land use and enter at the bottom of Column (2).
Step 3: Multiply the areas in Column (2) by the TN export Coefficients in Column (3) and enter
in Column (4).
Step 4: Total the TN exports for each type of land use and enter at the bottom of Column (4).
Step 5: Determine the export coefficient for site by dividing the total TN export from uses at the
bottom of Column (4) by the area at the bottom of Column (2).
(1) (2) (3) (4)
Type of Land Cover Areas TN export coefficient TN export from use
(acres) (Ibs/ac/yr) (Ibs/yr)
Permanently protected 0.000 0.60 0.000
undisturbed open space
(forest, unmown meadow)
Permanently protected 87.010 1.2 104.412
open space
(grass, landscaping, etc.)
Impervious surfaces 4.400 21.2 93.280
(roads, parking lots,
driveways, roofs, paved
storage areas, etc.)
TOTAL 91.410 -- T 197.692
Nitrogen Control Plan - September 2007
Method 2: CommerciaUlndustrial/Residential Sites with Known Impervious Area
Project Name: White Deer Park Date: 3/20/08
Applicant: _ Town of Garner Telephone:
Part I. Riparian Buffers
Does site contain riparian buffers? [ ] No Yes (show buffers on plan) [ ] Exempt (show basis for exemption)
Part II. Nitrogen Calculation
Item Proposed Site Information Area acres
1 Total project acreage
2 Total proposed impervious area 4.78 Ac
3 Existing impervious area (prior to 3/9/01 .38 Ac

4
New impervious area Item 2 - Item 3 _
4.40 Ac
5 Permanently protected undisturbed open sace _
0.00 Ac

6
Permanently protected managed open sace _
87.01 Ac
Pre-Develo me nt Loading
Type of Land Cover Area
ecres) TN export coefficient
lbs/ac/ r TN export from use
('.bs/ r
Existing forest land 76.80 _ 1.7 130.560

Existing pasture
_ 14.23
4.4 _
62.61
Existing residential 0.00 _ 7.5 0.00
Existing cropland --0.00 13.6 0
00
Existing commercial/industrial 0.38 - 13 --
.
4 94
TOTAL 91,41 198.12
Nitrogen
a TI?r.,..re.. I -A7.... D,..,. 1IL-d_I-. m_._. am Loading Rate' Ibs/ac r _
2.17

Post-Develo ment Loading before BMPs and/or Offset Payments
Type of Land Cover Area TN export coefficient TN export from
acres lbs/ac/ r use lbs/ r
Permanently protected undisturbed open space (forest,

unmown meadow, wetlands, buffers Item 5 0.00
0.6
0.00
Permanently protected managed open space
(grass, landscaping, etc. Item 6 87.01 1.2 104.42
Impervious surfaces (roads, parking lots, driveways,
roofs, paved storage areas, etc. Item 4 4.40 21.2 93.28
TOTAL 91.41
----------• 197.69
-

Item 7 • -----------•--
Item 8)
Nitrogen Loading Rate (lbs/ac/yr) (Equals Item 8 _ Item 7)
2.16
BMP Type TN Removal Rate % Check which apply
25
tland 40
WFilter 35
35
20
r Stri w/Level S reader 20
50 ' Restored or Additional Riparian buffer w/Level Spreader
30
D Detention 10

Amount of Offset (Pounds of Nitrogen) [Item 10 x (Item 1- Item 3)] N/A
*To Calculate the Amount of the Nitrogen Offset Payment Required to Be Paid to the NC EEP Use The Following Formula:
Amount of Offset Payment [Pounds of Nitrogen x $28.35 x 30 years]
Part III. Control of Peak Stormwater Flow
261.83 CFS
Calculated Pre-development Peak Flow (1-year)
Calculated Post-development Peak Flow without Controls (I-year) 261.83 CFS
Calculated Post-development Peak Flow with Controls (I-year) _ N/A
Calculations and details showing control of nitrogen and peak stormwater runoff control must be included.
Part IV: Watershed Development Permit
1. Total project acreage (in Lake Benson Watershed) 91.41 Ac
2. Total proposed impervious surface (in Lake Benson Watershed) 4.40 Ac
3. Existing impervious surface (in Lake Benson Watershed) * .38 Ac
4. Equivalent project acreage (Item 1 - Item 3) 91.03 Ac _
5. New impervious surface (Item 2 - Item 3) _ 4.02 Ac
6. Percent impervious [(Item 5 - Item 4) x 100] 4.41%
* Limited to impervious surface existing before 7/1/93
1, the undersigned, certify that to the best of my knowledge that the above information is correct (affix sea])
(sign)
To be filled in by staff
Project Watershed Protection Requirements
? Project Exempt: Explain
? Project Located in Lake Benson Conservation District - LBCD (Critical Area) Standards Apply
? Project Located Outside LBCD - On-site treatment required.
? Minor Variance Requested (WRB) Approved (date): Disapproved (date):
? Major Variance Requested (EMC) Approved (date): Disapproved (date):
Recommended by WRB (circle one): YES NO
Comments (use additional sheet if necessary)
Approved by Watershed Administrator: (sign)
Date:
Post-Development Loading after BMPs and/or Offset Payments
Item Description N-dro en Loadin Rate Ibs/ac/ r)
9 Nitro en load after BMPs show separately in detail N/A
10 Nitrogen load offset b payments Item 9 - 3.6 N/A
STEWART
Bioretention Area Sizing - BIO A
(for 85% TSS removal)
Project: White Deer Park
Number: C7005
Date: 28-Apr-07
Drainage Basin -Required Storag e for 1st inch of runoff
Total Drainage Area = 17424 sf Simple Method
Total Impervious Area = 13939 sf
Percent Impervious = 80% Rv = 0.05 + 0.009(I)
I = % impervious = 80%
Rainfall Depth = 1 in
Rv = 0.77 in
Volume = 1118 cf
e ulre Sur face Area
Ponding Depth = 9 in (max 12)
Required Storage Vol = 1118 cf
Minimum Surface Area _ 1491 sf
Average Length = 183 ft
Average Width = 10 ft
Surface Area provided = 1830 sf
Desiqn parameters from DENR Stormwater Best Mananement Pr
*Per NCDENR Manual
actices Manual, October 2007
421 Fayetteville Street, Suite 400, Raleigh, NC 27601 Tel [phone] Fax [phone] www.stewart-
eng.com

•
STEWART
Bioretention Area Sizing - BIO B
(for 85% TSS removal)
Project: White Deer Park
Number: C7005
Date: 28-Apr-07
Drainage Basin Required Storag e for 1st inch of runoff
Total Drainage Area = 20334 sf Simple Method
Total Impervious Area = 15911 sf
Percent Impervious = 78% Rv = 0.05 + 0.009(I)
I = % impervious = 78%
Rainfall Depth = 1 in
Rv, = 0.75 in
Volume = 1278 cf
e uire S urface Area
Ponding Depth = 9 in (max 12)
Required Storage Vol = 1278 cf
Minimum Surface Area = 1704 sf
Average Length = 171 ft
Average Width = 10 ft
Surface Area provided = 1710 sf
Design parameters from DENR Stormwater Best Management Pr
*Per NCDENR Manual
actices Manual, October 2007
421 Fayetteville Street, Suite 400, Raleigh, NC 27601 Tel [phone] Fax [phone] www.stewart-
eng.com
STEWART
Bioretention Area Sizing - BIO C
(for 85% TSS removal)
Project: White Deer Park
Number: C7005
Date: 28-Apr-07
Drainage Basin -Required Storag e for 1st inch of runoff
Total Drainage Area = 31467 sf Simple Method
Total Impervious Area = 26527 sf
Percent Impervious = 84%o Rv = 0.05 + 0.009(I)
I = % impervious = 84%
Rainfall Depth _ 1 in
Rv = 0.81 in
Volume= 2121 cf
*Per NCDENR Manual
actices Manual. October 2007
Drainage Basin Required Storag e for 1st inch of runoff
Total Drainage Area = 24584 sf Simple Method
Total Impervious Area = 19595 sf
Percent Impervious `= 80% Rv = 0.05 + 0.009(I)
I = % impervious = 80%
Rainfall Depth = 1 in
Rv = 0.77 in
Volume= ' 1572 cf
Required S urface Area
Ponding Depth = 9 in (max 12)
Required Storage Vol = 1572 cf
Minimum Surface Area = 2096 sf
Average Length = 178 ft
Average Width = 10 ft
Surface Area provided = 1780 sf
Design parameters from DENR Stormwater Best Management Pr
*Per NCDENR Manual
actices Manual. October 2007
421 Fayetteville Street, Suite 400, Raleigh, NC 27601 Tel [phone] Fax [phone] www.stewart-
eng.com
OPERATIONS AND MAINTENANCE MANUAL
November 2004
BEST MANAGEMENT PRACTICES
Garner, NC
Project Name: White Deer Park Date: 3/20/08
Property Owner/Responsible Party: Town of Garner
Address: _PO Box 446 Garner NC: 27529-0446
Telephone:
The maintenance of any Best Management Practice (BMP) installed to achieve nitrogen loading and/or
flow attenuating requirements for a development shall be the responsibility of the property owner or
other identified responsible party. In the case of residential or commercial subdivisions, Home Owners
Associations or Merchants Associations must be established in order to identify the responsible party.
This manual establishes general procedures for maintenance and operation of the allowed BMP types in
accordance with the Town of Garner Stormwater Program for Nitrogen Control. It is important to note
that only general maintenance tasks are identified here. All devices shall be maintained to original
design standards. This agreement shall be signed and notarized by the responsible party to perform the
tasks specified in the plan, including inspections, operation, and any needed maintenance activities.
1. BMP
Identify the types of BMPs located on the site and give a brief description on their design. If you
need additional space please attach separate pages to this document.
BMP Type Check which
apply Brief Description
Wet Pond
Stormwater Wetland
Sand Filter
Bioretention --'
Capturing drainage from proposed parking areas.
Grass Swale
Vegetated Filter Strip
w/Level Spreader
50' Restored or Additional
Riparian Buffer w/Level
Spreader
Dry Detention
Pagel of4
IL Maintenance
A. Wet Pond - Maintenance requirements are as follows:
I_ Debris and litter control checks for inlet, outlet, and orifice obstruction after every storm
producing runoff.
2. Provisions for routine vegetation management/mowing and a schedule for. these
activities.
3. Checks every 6 months, or more frequently, for:
a. Sediment buildup and the need for removal.
b. Erosion along the bank and the need for reseeding or stabilization and, if
reseeding is necessary, a reseeding schedule. ,
c. Erosion at the inlet and outlet and methods of stabilization.
d. Seepage through the dam.
e. Operation of any valves or mechanical components.
B. Stormwater Wetland - Maintenance requirements are as follows:
1. Wetlands will tend to collect debris, and it should be removed whenever it accumulates,
or at least twice annually.
2. Wetlands should be inspected annually after a rain even to ensure that the basin is
operating as designed.
3. At a minimum, items that should be included in the inspection are:
a. Clogging of the outlet or too rapid a release.
b. Erosion on the banks.
c. Erosion at the inlet and outlet.
d. Sediment accumulation and the need for removal.
e. Condition of the emergency spillway.
f. Woody vegetation in the embankment.
C. Sand Filter - Maintenance requirements are as follows:
1. At least once a year each filter must be inspected after a storm to determine if the filter
bed is passing the runoff as expected.
2. Maintenance operations must be performed when storms of approximately one inch are
not passing through the filter within 24 hours. Maintenance consists of removing the first
two or three inches of discolored sand, and replacing this with new sand. The sand that
has been removed would then be dewatered, if necessary, and then landfilled.
3. At the same time that maintenance is performed on the sand chamber, the sediment
chamber should also be pumped and cleaned. It is most likely that the sediment removed
from the first chamber will need to be dewatered before it is allowed to be dumped at a
landfill.
D. Bioretention - Maintenance requirements are as follows:
1. Visually inspect and repair soil erosion on a monthly basis.
2. Remulch any void area whenever necessary. Replacement of mulch layers may be
necessary every two or three years. Mulch should be replaced in the spring. When the
mulch layer is replaced, the previous layer should be removed first.
3. Remove and replace all dead and diseased vegetation considered beyond treatment. This
should be done twice a year, once in the spring and once in the fall. Treat all diseased
trees and shrubs that are not beyond treatment as needed.
Page 2 of 4
i
E. Grass Swale - Maintenance requirements are as follows:
1. At least once annually, remove excess sediment, especially from the upstream edge, to
maintain original contours and grading.
2. At least once annually, repair any erosion and regrade the swale to ensure that the runoff
flows evenly in a thin sheet through the Swale.
3. At least once annually, inspect vegetation and revegetate the swale to maintain_ a dense
growth of vegetation.
4. Grassed swales shall be mowed at least twice annually to a minimum height of six inches.
F. Vegetated Filter Strip with Level Spreader - Maintenance requirements are as follows:
1. At least once annually, remove deposited sediment, especially from the upstream edge, to
maintain original contours and grading.
2. Repair channels that form and regrade the filter strip to ensure that the runoff flows
evenly in a thin sheet over the filter strip:
3. Repair level spreader whose disrepair can cause the formation of channels in the filter
strip.
4. Reseed and regrade the filter strip to maintain a dense growth of vegetation, especially if
the strip has been used for sediment control.
5. Grassed filter strips shall be mowed at least twice annually to a minimum height of six
inches.
G. 50' Restored or Additional Riparian Buffer with Level Spreader - Restored or additional
riparian buffers used for nitrogen reduction should be left in an undisturbed condition. Only
maintenance activities allowed by the buffer rules would be allowed. Any level spreaders used
to diffuse flow into the buffer should be maintained as required in section II.F.
H. Dry Detention -Maintenance requirements areas follows:
a. All grassed areas of a dry detention basin should be mowed at least twice annually.
b. Dry detention basins will tend to collect debris, and it should be removed whenever it
accumulates, or at least twice annually.
c. Pond should be inspected annually after a rain event to ensure that the basin is operating
as designed.
4. At a minimum, items that should be included in the inspection are:
a. Clogging of the outlet or too rapid a release.
b. Erosion on the banks.
c. Erosion at the inlet and outlet.
d. Sediment accumulation and the need for removal.
e. Condition of the emergency spillway.
f. Woody vegetation in the embankment.
The Town will inspect. BMPs on an annual basis and forward a list of any required deficiencies or
repairs to the property owner/responsible party. The property owner/responsible party will have 90 days
to correct all deficiencies and make all repairs to the satisfaction of the Town Engineer. Failure to
satisfactorily complete the repairs within the 90 days will cause the BMP to be declared a nuisance as
provided for in Section 6-17 of the Garner Town Code. Abatement of the nuisance will proceed as
provided for in Chapter 6, Article II of the Garner Town Code.
Page 3 of 4

STORMWATER BEST MANAGEMENT PRACTICES
OPERATIONS AND MAINTENANCE AGREEMENT
Property Owner/Responsible Party
Sign:
Print:
STATE OF NORTH CAROLINA
COUNTY OF WAKE
I, a Notary Public for said County and State, do hereby certify
that personally appeared before me this day and acknowledged
the due execution of the foregoing instrument.
Witness my hand and official seal, this the day of ,
Official Seal
My commission expires
Notary Public
LANDSCAPING COMMENTS
Please contact Jennifer Collins, Urban Design Specialist at 772-4688 regarding the attached
landscaping comments.
ENGINEERING DEPARTMENT
Please contact Frank Powell, the Town Engineer at 772-4688 regarding the attached engineering
comments.
PUBLIC UTILITIES
Please contact Danielle Barber, with the City of Raleigh, at 831-6162 regarding the public
utilities comments.
PUBLIC WORKS
Please contact Paul Cox at 772-7600 regarding the attached public works comments.
BUILDING AND FIRE INSPECTIONS
Please contact Les Harmon in the Building Inspections Department at 772-4688 regarding the
attached inspections continents.
Please note the following fees. Please review with the appropriate departments to
determine the amount and if applicable for this project.
PLANNING FEES BUILDING PERMIT ENGINEERING FEES:
FEES
Master Sign Plan Building Permit Utility Development Fees ,
Sign Permit Garbage Container Sewer Capacity Replacement Fees
Final Plat Meter Fees Water Capacity Replacement Fees
Subdivision Exemption Water Tap Fee Fee-In-Lieu of Nitrogen Reduction
Easement Dedication Sewer Tap Fee Maintenance Fee
Sewer Acreage Fee Street Inspection Fees
Water Acreage Fee Street Signs
Engineering Tap
Inspection Fees
c: Jennifer Collins, Urban Design Specialist Danielle Barber, City of Raleigh
Brad Bass, Planning Director Paul Cox, Public Works
Jaclyn Sumner, Engineering Sandy Teal & Les Harmon, Building Inspection
Frank Powell, PE, Town Engineer Jenny Saldi, Senior Planner
H:\PLA-03\badwp2004\PLANREVUWemo 08\supsp0805.doc
STEWARTI
RIPRAP OUTLET PROTECTION WORKSHEET
Project White Deer Park Date 24-Apr-08
Project No. C7005 Designer A.CP
Outlet ID CV-1
Outlet flowrate 3.5 cfs
Pipe diameter 12 inches
Outlet pipe slope 1.31 percent
Full flow velocity 4.5 ft/sec
Figure 8.06.b.1
2'
I
20
Zone
U
15
Zone 5
y 10
i
-zone 3
5
-zo Re
t
0
0 1 2 3 4 5 6 7 8 9 10
Pipe diameter (ft)
Zone from graph above = 1
Outlet pipe diameter 12 in. Length = 4.0 ft.
Outlet flowrate 3.5 cls Width = 3.0 fl.
Outlet velocity 4.5 ft/sec Stone diameter = 3 in.
Material = Class A Thickness = 9 in.
Zone Material Diameter Thickness Length Width
1 Class A 3 9 4 x D(o) 3 x D(o)
2 Class B 6 22 6 x D(o) 3 x D(o)
3 Class I 13 22 8 x D(o) 3 x D(o)
4 Class I 13 22 8 x D(o) 3 x D(o)
5 Class 11 23 27 10 x D(o) 3 x D(o)
6 Class II 23 27 10 x D(o) 3 x D(o)
7 Special stud required
Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual
STEWART
RIPRAP OUTLET PROTECTION WORKSHEET
Project White Deer Park Date 24-Apr-08
Project No. 07005 Designer ACP
Outlet ID CV-2
Outlet flowrate 8,1 cfs
Pipe diameter 18 inches
Outlet pipe slope 1.56 percent
Full flow velocity 4.6 ft/sec
Figure 8.06.b.1
25
Zone 7
20
Zone 6
V
iS
'r
V
Zone
2
> Zone 4
5
-Z net
Zone 3,
Zone 2
0
0 1 2 3 4 5 6 7 8 9 10
Pipe diameter (ft)
Zone from graph above = 1
Outlet pipe diameter 18 in. Length = 6.0 ft.
Outlet flowrate 8.1 cfs Width = 4,5 fl,
Outlet velocity 4.6 ft'sec Stone diameter = 3 in.
Material = Class A Thickness = 9 in.
Zone Material Diameter Thickness Length Width
1 Class A 3 9 4 x D(o) 3 x D(o)
2 Class B 6 22 6 x D(o) 3 x D(o)
3 Class I 13 22 8 x D(o) 3 x D(o)
4 Class I 13 22 8 x D(o) 3 x D(o)
5 Class II 23 27 10 x D(o) 3 x D(o)
6 Class II 23 27 10 x D(o) 3 x D(o)
7 Special stud required
Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual
RIPRAP OUTLET PROTECTION WORKSHEET
Project White Deer Park Date 24-Apr-08
Project No. C7005 Designer ACP
Outlet ID CV-3
Outlet flowrate 4 cfs
Pipe diameter 15 inches
Outlet pipe slope 7.5 percent
Full flow velocity 3.3 ft/sec
- FiQUre 8.06.b.1 -?
25
zonel
f 20
ione?
15
U
Zones
zone 4
1
0
5
Zone I
0
0 1 2 3 4 5 6 7 8 9 10
Pipe diameter (ft)
Zone from graph above = 1
Outlet pipe diameter 15 in. Length = 5.0 ft.
Outlet flowrate 4.0 cf:s Width 3.8 fl.
Outlet velocity 3.3 fl/sec Stone diameter = 3 in.
Material = Class A Thickness = 9 in.
Zone Material Diameter Thickness Length Width
1 Class A 3 9 4 x D(o) 3 x D(o)
2 Class B 6 22 6 x D(o) 3 x D(o)
3 Class I 13 22 8 x D(o) 3 x D(o)
4 Class I 13 22 8 x D(o) 3 x D(o)
5 Class H 23 27 10 x D(o) 3 x D(o)
6 Class II 23 27 10 x D(o) 3 x D(o)
7 Special stud required
uaicuiations oasea on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual
STEWART
RIPRAP OUTLET PROTECTION WORKSHEET
Project White :Deer Park Date 24-Apr-08
Project No. C7005 Designer ACP
Outlet ID CV-4
Outlet flowrate 18.6 cfs
Pipe diameter 24 inches
Outlet pipe slope 2.94 percent
Full flow velocity 5.9 ft/sec
Figure 8.06.61
25
I
20
zone6
y 15
Z 0 He 5'
° 10
5
4
0
0 1 2 3 4 5 6 7 8 9 10
Pipe diameter (ft)
f
I
Zone from graph above = 2
Outlet pipe diameter 24 in. Length = 12.0 ft.
Outlet flowrate 18.6 cis Width = 6.0f.
Outlet velocity 5.9 fUsec Stone diameter = 6 in.
Material = Class B Thickness = 22 ln.
Zone Material Diameter Thickness Length Width
1 Class A 3 9 4 x D(o) 3 x D(o)
2 Class B 6 22 6 x D(o) 3 x D(o)
3 Class I 13 22 8 x D(o) 3 x D(o)
4 Class I 13 22 8 x D(o) 3 x D(o)
5 Class 11 23 27 10 x D(o) 3 x D(o)
6 Class II 23 27 10 x D(o) 3 x D(o)
7 Special stud required
t;atcutations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual
STEWAERT
RIPRAP OUTLET PROTECTION WORKSHEET
Project White Deer Park Date 24-Apr-08
Project No. 07005 Designer ACP
Outlet ID CV-5
Outlet flowrate 0.95 cfs
Pipe diameter 15 inches
Outlet pipe slope 7.14 percent
Full flow velocity 0.8 ft/sec
Figure 8.06.b.1
25
:T 7- 1
20
r 15
10
zone
f 5 --Zone I
Zone 2
0
0 1 2 3 4 5 6 7 8 9 10
Pipe diameter (ft)
Zone from graph above = 1
Outlet pipe diameter 15 in. Length = 5.0 ft.
Outlet flowrate 1.0 cfs Width = 3.811.
Outlet velocity 0.8 11/sec Stone diameter = 3 in.
Material = Class A Thickness = 9 in.
Zone Material Diameter Thickness Length Width
1 Class A 3 9 4 x D(o) 3 x D(o)
2 Class B 6 22 6 x D(o) 3 x D(o)
3 Class I 13 22 8 x D(o) 3 x D(o)
4 Class I 13 22 8 x D(o) 3 x D(o)
5 Class II 23 27 10 x D(o) 3 x D(o)
6 Class II 23 27 10 x D(o) 3 x D(o)
7 Special stud required
Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual
STEWARTI
RIPRAP OUTLET PROTECTION WORKSHEET
Project White Deer Park Date 24-Apr-08
Project No. 07005 Designer ACP
Outlet ID CV-6
Outlet flowrate 5 cfs
Pipe diameter 15 inches
Outlet pipe slope 10.7 percent
Full flow velocity 4.1 ft/sec
Figure 8.06.b.1
25
20
Zone 6
d 15
_2 10
Zone 4
I
j
0
41-
0 1 2 3 4 5 6 7 8 9 10 11
Pipe diameter (ft)
Zone from graph above = 1
Outlet pipe diameter 15 in. Length = 5.0 ft.
Outlet flowrate 5.0 aPs Width = 3.811.
Outlet velocity 4.1 ft./sec Stone diameter = 3 in.
Material = Class A Thickness = 9 in.
Zone Material Diameter Thickness Length Width
1 Class A 3 9 4 x D(o) 3 x D(o)
2 Class B 6 22 6 x D(o) 3 x D(o)
3 Class I 13 22 8 x D(o) 3 x D(o)
4 Class I 13 22 8 x D(o) 3 x D(o)
5 Class 11 23 27 10 x D(o) 3 x D(o)
6 Class II 23 27 10 x D(o) 3 x D(o)
7 Special stud required
Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual
STEWART
RIPRAP OUTLET PROTECTION WORKSHEET
Project White Deer Park Date 24-Apr-08
Project No. C7005 Designer ACP
Outlet ID CV-7
Outlet flowrate 3.2 cfs
Pipe diameter 15 inches
Outlet pipe slope 122 percent
Full flow velocity 2.6 ft/sec
Fieure 8.06.b.1
4 25
r
20
f
V
u
Zone 5
y 10
Zone 4
5
'ec
Zone2
0
0 1 2 3 4 5 6 7 8 9 10
Pipe diameter (ft)
Zone from graph above = 1
Outlet pipe diameter 15 in. Length = 5.0 ft:
Outlet flowrate 3.2 cfs Width = 3.8 11.
Outlet velocity 2.6 fusec Stone diameter = 3 in.
Material = glass A Thickness = 9 in.
Zone Material Diameter Thickness Length Width
1 Class A 3 9 4 x D(o) 3 x D(o)
2 Class B 6 22 6 x D(o) 3 x D(o)
3 Class I 13 22 8 x D(o) 3 x D(o)
4 Class I 13 22 8 x D(o) 3 x D(o)
5 Class Il 23 27 10 x D(o) 3 x D(o)
6 Class II 23 27 10 x D(o) 3 x D(o)
7 Special stud required
t-aicutattons based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual
STEWART'
RIPRAP OUTLET PROTECTION WORKSHEET
Project White Deer Park Date 24-Apr-08
Project No. C7005 Designer ACP
Outlet ID CV-8
Outlet flowrate 28 cfs
Pipe diameter 30 inches
Outlet pipe slope 5.56 percent
Full flow velocity 5.7 ft/sec
Fieure 8.06.b.1
25
Zone. 7
20
15
w
Lone
to
-Zone 4
5
o
0 1 2 3 4 5 6 7 8 9 10
4
Pipe diameter (ft)
Zone from graph above = 2
Outlet pipe diameter 30 in. Length = 15.0 ft.
Outlet flowrate 28.0 cfs Width = 7.5 ft.
Outlet velocity 5.7 ft/sec Stone diameter = 6 in.
Material = Class B Thickness = 22 in.
Zone Material Diameter Thickness Length Width
1 Class A 3 9 4 x D(o) 3 x D(o)
2 Class B 6 22 6 x D(o) 3 x D(o)
3 Class I 13 22 8 x D(o) 3 x D(o)
4 Class I 13 22 8 x D(o) 3 x D(o)
5 Class H 23 27 10 x D(o) 3 x D(o)
6 Class II 23 27 10 x D(o) 3 x D(o)
7 Special stud required
Calculation based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual
RIPRAP OUTLET PROTECTION WORKSHEET
Project White Deer Park Date 24-Apr-08
Project No. C,7005 Designer ACP
Outlet ID CV-9
Outlet flowrate 0.52 cfs
Pipe diameter 15 inches
Outlet pipe slope 4.17 percent
Full flow velocity 0.4 ft/sec
Figure 8.06.b.1
I 25
20
Zone 6
15
V
rr•
zone5
I m
5
0
0 1 2 3 4 5 6 7 8 9 10
Pipe diameter (ft)
Zone from graph above = 1
Outlet pipe diameter 15 in. Length = 5.0 ft.
Outlet flowrate 0.5 cfs Width = 3.811.
Outlet velocity 0.4 ft,see Stone diameter= 3 in.
Material = Class A Thickness = 9 in.
Zone Material Diameter Thickness Length Width
1 Class A 3 9 4 x D(o) 3 x D(o)
2 Class B 6 22 6 x D(o) 3 x D(o)
3 Class I 13 22 8 x D(o) 3 x D(o)
4 Class I 13 22 8 x D(o) 3 x D(o)
5 Class H 23 27 10 x D(o) 3 x D(o)
6 Class II 23 27 10 x D(o) 3 x D(o)
7 Special stud required
Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual
STEWART
RIPRAP OUTLET PROTECTION WORKSHEET
Project White Deer Park. Date '14-Apr-08
Project No. 07045 Designer ACP
Outlet ID CV-10
Outlet flowrate 1.2 cfs
Pipe diameter 15 inches
Outlet pipe slope 0 percent
Full flow velocity 1.0 ft/sec
Figure 8.06.b.1
25
Zone 7
?r 20
J
15
-L- Zone 5
10
Zone 4
5
Zone
0
0 1 2 3 4 5 6 7 8 9 10
Pipe diameter (ft)
Zone from graph above = 1
Outlet pipe diameter 15 in. Length = 5.0 ft.
Outlet flowrate 1.2 cfs Width = 3.811.
Outlet velocity 1.0 ft/sec Stone diameter = 3 in.
Material = Class A Thickness = 9 in.
Zone Material Diameter Thickness Length Width
I Class A 3 9 4 x D(o) 3 x D(o)
2 Class B 6 22 6 x D(o) 3 x D(o)
3 Class I 13 22 8 x D(o) 3 x D(o)
4 Class I 13 22 8 x D(o) 3 x D(o)
5 Class 11 23 27 10 x D(o) 3 x D(o)
6 Class II 23 27 10 x D(o) 3 x D(o)
7 Special stud required
Calculations based on NY DOT method -,Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual
RIPRAP OUTLET PROTECTION WORKSHEET
Project White Deer Park Date 24-Apr-08
Project No. C7005 Designer ACP
Outlet ID CV-11
Outlet flowrate 0.6 cfs
Pipe diameter 15 inches
Outlet pipe slope 1 percent
Full flow velocity 0.5 ft/sec
Fiaure 8.06.b.1
25
Zone 7 -1'
20
15
4 u
y
10
_Zone 4
5
Zo -A
Z 6e I' nejD
Zone 2
0
0 I 2 3 4 5 6 7 8 9 10
Pipe diameter (ft)
Zone from graph above = l
Outlet pipe diameter 15 in. Length = 5.0 ft.
Outlet flowrate 0.6 cfs Width = 18 11.
Outlet velocity 0.5 ft/sec Stone diameter = 3 in.
Material = Class A Thickness = 9 in.
Zone
1 Material
Class A Diameter
3 Thickness
9 Length
4 x D(o) Width
3 x D(o)
2 Class B 6 22 6 x D(o) 3 x D(o)
3 Class I 13
_
_ 22 8 x D(o) 3 x D(o)
4 Class I T3 22 8 x D(o) 3 x D(o)
5 Class H 23 27 10 x D(o) 3 x D(o)
6 Class II 23 27 10 x D(o) 3 x D(o)
7 Special stud required
Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual
STEWART'
RIPRAP OUTLET PROTECTION WORKSHEET
Project White Deer Park bate 24-Apr-08
Project No. C7005 Designer ACP
Outlet ID CV-12
Outlet flowrate 2.9 cfs
Pipe diameter 15 inches
Outlet pipe slope 0 percent
Full flow velocity 2..4 ft/sec
Fieure 8.06.b.1
25
one
20
i`
Zone 5
2 10
>
5
Zone I
_Zone 3
t
0
0 1 2 3 4 5 6 7 8 9 10 1
Pipe diameter (ft)
i
i
Zone from graph above = 1
Outlet pipe diameter 15 in. Length= 5.0 ft.
Outlet flowrate 2.9 cis Width = 3.8 fl.
Outlet velocity 2.4 ft/sec Stone diameter = 3 in.
Material = Class A Thickness = 9 in.
Zone Material Diameter Thickness Length Width
1 Class A 3 9 4 x D(o) 3 x D(o)
2 Class B 6 22 6 x D(o) 3 x D(o)
3 Class I 13 22 8 x D(o) 3 x D(o)
4 Class I 13 22 8 x D(o) 3 x D(o)
5 Class II 23 27 10 x D(o) 3 x D(o)
6 Class II 23 27 10 x D(o) 3 x D(o)
7 Special stud required
Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual
STEWART
RIPRAP OUTLET PROTECTION WORKSHEET
Project White Deer Park Date 24-Apr-08
Project No. C7005 Designer ACP
Outlet ID FpS-3
Outlet flowrate 7.79 cfs
Pipe diameter 18 inches
Outlet pipe slope 0.5 percent
Full flow velocity 4.4 ft/sec
Figure 8.06.b.1
25
zone

20

Zone6

y 15
h

2 10
>

5

0
0 1 2

Zone from graph above =
Outlet pipe diameter
Outlet flowrate
Outlet velocity
Material = 3

1
18 in.
7.8 cis
4.4 ft./sec
Class A 4 5 6
Pipe diameter (ft)

Length =
Width =
Stone diameter =
Thickness = 7 8 _9 10

6.0 ft.
4.5 fl.
3 in.
9 in.

Zone Material Diameter Thickness Length Width
1 Class A 3 9 4 x D(o) 3 x D(o)
2 Class B 6 22 6 x D(o) 3 x D(o)
3 Class I 13 22 8 x D( o) 3 x D( o)
4 Class i 13 22 8 x D(o) 3 x D(o)
5 Class II 23 27 10 x D(o) 3 x D(o)
6 Class II 23 27 10 x D(o) 3 x D(o)
7 Special stud required
Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual
STEWARTI
RIPRAP OUTLET PROTECTION WORKSHEET
Project White Deer Park Date 24-Apr-08
Project No. 07005 Designer ACP
Outlet ID FES-4
Outlet flowrate 5.73 cfs
Pipe diameter 18 inches
Outlet pipe slope 0.8 percent
Full flow velocity 3.2 ft/sec
Figure 8.06.b.1
25
20
15
w
T
.2 10
ZZ one 5J
Zone 4
5
0
0 1 2 3 4 j 6 7 8 9 t0
Pipe diameter (ft)
j
Zone from graph above = 1
Outlet pipe diameter 18 in. Length = 6.0 ft.
Outlet flowrate 5.7 cis Width = 4.511.
Outlet velocity 3.2 fbsec Stone diameter = 3 in.
Material = Class A Thickness = 9 in.
Zone Material Diameter Thickness Length Width
1 Class A 3 9 4 x D(o) 3 x D(o)
2 Class B 6 22 6 x D(o) 3 x D(o)
3 Class I 13 22 8 x D(o) 3 x D(o)
4 Class I 13 22 8 x D(o) 3 x D(o)
5 Class II 23 27 10 x D(o) . 3 x D(o)
6 Class II 23 27 10 x D(o) 3 x D(o)
7 Special study required
Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual
Bentley Systems, Inc. Haestad Methods Solution Bentley StormCAD V8 XM Edition
White Deer roadway.stc Center [08.09.081.00]
27 Siemon Company Drive Suite 200 W
4/2&2008 Watertown, CT 06795 USA [phone] Page 1 of 1
s
Calculation Detailed Summary
Element Details
ID 13 Notes
Label Base Calculation
Options
Hydraulic Summary
Flow Profile Method Backwater Analysis Average Velocity Actual Uniform Flow
Method Velocity
Number of Flow Profil e Minimum Structure
Steps 5 Headloss 0.00 ft
Hydraulic Grade Minimum Time of
Convergence Test 0.001 ft Concentration 5.000 min .

Inlets
Neglect Side Flow? False Active Components for
Combination Inlets in Grate and Curb
Sag
Neglect Gutter Cross Active Components for
Slope For Side Flow? True Combination Inlets on Grate and Curb
Grade

HEC-22
Elevations Considered Depressed
Equal Within 0.50 ft Unsubmerged 1.000
Consider Non-Piped Half Bench Submerged
False 0.950
Plunging Flow
Flat Submerged 1.000 Half Bench
Unsubmerged 0.150
Flat Unsubmerged 1.000 Full Bench Submerged 0.750
Depressed Submerged 1.000 Full Bench
Unsubmerged 0.070

AASHTO
Expansion, Ke 0.350 Shaping Adjustment, Cs 0.500
Contraction, Kc 0.250 Non-Piped Flow
Adjustment, Cn 1.300
Bend Angle VS. Bend LOSS Curve
Send Angle, Bend Lo55 Coefficient,` Kb
(degrees)
0.00 0.000
15.00 0.190
30.00 0.350
45.00 0.470
60.00 0.560
75.00 0.640
90.00 0.700

White Deer roadway
stc Bentley Systems, Inc. Haestad Methods Solution Bentley StormCAD V8 XM Edition
. Center [08.09.081.00]

4/2812008 27 Siemon Company Drive Suite 200 W
Watertown, CT 06795 USA [phone] Page 1 of 3
•
Calculation Detailed Summary
Generic Structure Loss
Governing Upstream Pipe with Maximum
Pipe Selection Method QV
- Catchment Summary
Label Area Timc of Concentration Rational C Catchment CA
nacres) (min) (acres)'
CB-1 CATCH 0.135 5.000 0.950 0.129
C13-2 CATCH 0.175 5.000 0.950 0.166
CB-3 CATCH 0.317 5.000 0.950 0.301
C:atChment Intensity Catchment Rational
(in!hr) Flow
(ft3/s)
7.220 0.94
7.220 1.21
7.220 2.19
Conduit Summary
Label Conduit Conduit Shape Branch ID Subnetwork Flow
Description O€itfall (ft3/G)
CO-1 Circular Pipe -
15.0 in Circular Pipe 3 FES-2 1.01
CO-2 Circular Pipe -
15.0 in Circular Pipe 3 FES-2 2.50
CO-3 Circular Pipe -
15.0 in Circular Pipe 4 FES-1 0.74
CO-4 Circular Pipe - Circular Pipe 1 FES-3 3
22
15.0 in .
CO-5 Circular Pipe -
18.0 in Circular Pipe 1 FES-3 4.57
CO-6 Circular Pipe -
15.0 in Circular Pipe 2 FES-4 2.62
CO-7 Circular Pipe -
12.0 in Circular Pipe 2 FES-4 3.11
velocity ! Hydraulic Grade Hydraulic Grade Depth (In) Depth (Out)
(Average) Line (In) Line (Out) `- (ft) ft)
(ft/s) ` ,`ft)' (€t)
3.37 289.20 287.82 0.40 0.52
4.33 287.73 287.10 0.63 0.60
3.55 292.34 291.98 0.34 0.28
6.56 268.14 265.40 0.72 0.98
4.72 265.24 264.56 0.82 0.81
3.78 273.14 273.03 0.72 0.93
4.58 272.91 272.06 0.81 0.76
Node Summary
Labe( Element Type Subnetwork Outfatl Flow (Total Surface) Flow (Total Out)
(fta/s)> (ft3/s)
Bentley Systems, Inc. Haestad Methods Solution Bentley StormCAD V8 XM Edition
White Deer roadway.stc Center [08.09.081.00]
27 Siemon Company Drive Suite 200 W Page 2 of 3
4/2812008 Watertown, CT 06795 USA [phone]
i
1
CB-1
Catch Basin FES-2 1.21 1.01
CB-3 Catch Basin FES-2 2.19 2.50
RISER D Catch Basin FES-3 3.22 3.22
RISER C Catch Basin FES-3 4.57 4.57
RISER A Catch Basin FES-4 2.62 2.62
RISER B Catch Basin FES-4 3.11 3.11
Elevation (Ground) Elevation (Invert) Energy Grade Line (In) Energy Grade Line
(ft) ) (ft) (Out)
(ft)
295.00 292.00 292.48 292.46
291.50 288.80 289.36 289.34
289.70 287.10 288.07 287.98
272.42 267.42 268.49 268.44
269.42 264.42 265.73 265.57
277.42 272.42 273.37 273.34
277.42 272.10 273.36 273.23
Inlet Summary
Label InletType InletType '(Inlet) Inlet
Flow (Total
Intercepted)
(ft3/sl
CB-1 Catalog Inlet Combination NCDOT TYPE F 0.74
CB-2 Catalog Inlet Combination NCDOT TYPE F 1.01
CB-3 Catalog Inlet Combination NCDOT TYPE F 1.57
RISER D Percent Capture (N/A) (N/A) 0.00
RISER C Percent Capture (N/A) (N/A) 0.00
RISER A Percent Capture (N/A) (N/A) 0.00
RISER B Percent Capture (N/A) (N/A) 0.00
Flow (Total Bypassed) Bypass Target Capture Efficiency Gutter Depth Gutter Spread
(L r<;) (Calculated) (in) (ft)
(%)
0.19 CB-2 79.4 1.4 5.7
0.39 CB-3 72.0 1.6 6.7
1.01 <None> 60.9 2.0 8.4
0.00 <None> 100.0 0.0 0.0
0.00 <None> 100.0 0.0 0.0
0.00 <None> 100.0 0.0 0.0
0.00 <None> 100.0 0.0 0.0
Bentley Systems, Inc. Haestad Methods Solution Bentley StormCAD V8 XM Edition
White Deer roadway.stc Center [08.09.081.00]
27 Siemon Company Drive Suite 200 W Page 3 of 3
4/28/2008 Watertown, CT 06795 USA [phone]
Calculation Detailed Summary
Node Summary
Label Element Type Subnetwork Outfall Flow (Total Surface) Flow (Total Out)
(tt,?) (ft,/s)
Catch Basin FES-1 0.94 0.74