20080499 Ver 1_Stormwater Info_20080317

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March 6, 2008
PROJECT HERMES
KERNERSVILLE, NORTH CAROLINA
q1
Schneider
DESIGNER:
Andrew R. Gullone, E.I.T.
THE SCHNEIDER CORPORATION
8001 Arrowridge Blvd
Charlotte, NC 28273
Phone: [phone]
Fax: [phone]
A'ETIAN;;,_
BRANCH
Andrew M. Scales
P.E. NO. 033687
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TABLE OF CONTENTS
Drainage Narrative
Site Information
Soils Map
Soil Classifications
Runoff Curve Numbers
North Carolina Rainfall Data
Erosion Control
Sediment Basin Calculations
Existing Conditions
Existing Basin Map
Time of Concentration Calculations
Curve Number Calculations
ICPR Schematic
ICPR Input Data
ICPR Node Maximum
ICPR Basin Maximum
ICPR Basin Summary
Time v. Outflow
Proposed Conditions
Proposed Basin Map
Time of Concentration Calculations
Curve Number Calculations
ICPR Schematic
ICPR Input Data
ICPR Node Maximum
ICPR Link Maximum
[CPR Basin Maximum
ICPR Basin Summary
Wet Pond Design
Wet Pond Cross Sections
Wet Pond 1
Impervious Area Calculations
Water Quality Design Calculations
Wet Detention Basin Supplement
Wet Detention Basin Specifications
Appendix A
Appendix B
Appendix C
Appendix D
See Plan Sheet 8102
Appendix E
See Plan Sheet 8103
Appendix F
See Plan Sheet C803
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DRAINAGE NARRATIVE
' Design Criteria:
' These drainage calculations are based on given data and design criteria as follows:
Design Procedure:
' The Schneider Corporation first looked at the existing conditions of the site. Existing drainage
basins, offsite drainage, soil conditions and time of concentrations were calculated. Existing flows
were calculated using the program Interconnected Channel and Pond Routing Model (ICPR).
' Second, the proposed conditions were evaluated and sizing the wet ponds.
Site location:
' The proposed project is located on 127.3 acres in between Old Greensboro Road and Business
Interstate 40 (BUS 1-40).
' Terrain and existing ground condition:
' The proposed site consists of 127.3 acres of woods and pasture on a level and rolling terrain ranging
from 4%-25%. The site is bound to the north by Old Greensboro Road and the south by BUS 1-40. A
wetland area bounds the site to the east and woods bound the site to the west. The overall site has
86' of relief, with elevations ranging from 966.00 M.S.L. to 880.00 M.S.L. A ridgeline divides the site
' near the middle of the property. Overland flow primarily drains down from the ridges of the hills into
natural depressions and ditches which flow to the small tributaries and then to the river.
' Adjoining land conditions:
North: Vacant
South: Vacant
East: Vacant
West: Residential Subdivsion
' Soil types:
Soils maps from the United States Department of Agriculture, Soil Conservation service identify
Appling, Cecil, Chewacla, Congaree, Enon and Madison soils on the subject site
Th
A
li
t .
e
pp
ng,
Cecil, Congaree and Madison soils are categorized as ApB, CcB, CeB2
Co
MaB
McB2
McD2
,
,
,
,
and McE2 are part of hydrologic group B. The Chewacla and Enon are categorized as Ch and
EnD are part of hydrologic group C.
'
Overall Existing Drainage:
' In the existing state, the site drains from Old Greensboro Road to BUS 1-40. A ridgeline divides the
site into two existing basins which drain into wetland areas and under BUS 1-40. The two (2) existing
basins in the site are labeled as EX1, and EX2. EX1 drains to a wetland area in the southwest corner
of the site. EX2 drains into a wetland area in the southeast corner of the site. Both wetland drain
under BUS 1-40 and join together approximately 1500 feet downstream.
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Overall Proposed Drainage Design:
In the developed state, the proposed site will mainly be pavement and buildings with some
undisturbed areas. Due to the amount of impervious area, the site is classified as a high-deri.sity
project. The site will include one (1) Best Management Practice Ponds that will collect and treat all of
the impervious drainage area for the proposed site. This pond is labeled as Wet Pond 1. This pond
will control and treat the runoff volume of the 1 inch, 24 hour storm. The main outlet structures have
been designed to the 1 year, 2 year, 10 year and 25 year, 24 hour storm events. An emergency weir
will pass the 50 year and 100 year, 24 hour storm events. A level spreader will be installed at the
outfall of the pipe to prevent a concentrated release point and help prevent erosion.
Per the Kernersville Unified Development Ordinance, the post-development stormwater runoff
volume for a high-density project must be less than the pre-development runoff volume for the 1
year, 24 hour storm. The first 1 inch of stormwater runoff must also be treated to remove 85% of
total suspended solids (TSS). T he North Carolina Division of Water Quality Stormwater Best
Management Practices Manual will also be utilized to design the wet pond (See Appendix F).
In addition to meeting both the Kernersville LIDO and the NC DWQ BMP manual, the post-
development release rates for the 2 year, 10 year, 25 year, 50 year and 100 year 24 hour storm
events were less than the pre-development release rates for the same storm events.
1. Wet Pond 1
1YR Dev. vs. 1YR Pre-dev.
• Allowable Release Rates (Time 12.50 hrs)
• EX 1 9.68cfs
• EX 2 19.79cfs
• Total 29.47cfs
• Developed Release Rates
• OUTLET 1
4.98cfs
2YR Dev. vs. 2YR Pre-dev.
• Allowable Release Rates (Time 12.42)
• EX 1 13.48cfs
' EX 2 21.17cfs
• Total 34.65cfs
• Developed Release Rates
' • OUTLET 1 6.52cfs
10YR Dev. vs. 10YR Pre-dev.
' • Allowable Release Rates (Time 12.33)
• EX 1 59.50cfs
• EX 2 59.53cfs
' • Total 119.03cfs
• Developed Release Rates
• OUTLET 1 66.13cfs
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25YR Dev. vs. 25YR Pre-dev.
' • Allowable Release Rates (Time 12.331
• EX 1
• EX 2
' Total
• Developed Release Rates
• OUTLET 1

50YR Dev. vs. 50YR Pre-dev
73.66cfs
71.89cfs
145.55cfs
86.70cfs
• Allowable Release Rates (Time 12.33)
• EX 1 107.54cfs
• EX 2 101.04cfs
• Total 208.58cfs
t • Developed Release Rates
• OUTLET 1 140.23cfs
' 100YR Dev. vs. 100YR Pre-dev.
• Allowable Release Rates (Time 12
33)
.
• EX 1 136.51 cfs
• EX 2 125.66cfs
• Total 262.17cfs

' • Developed Release Rates
• OUTLET 1
245.72cfs
' Riser Sediment Basins:
In order to prevent sediment from leaving the site during construction Sediment Basins and Riser
Type Sediment Basins will be constructed. A double row of high hazard silt fence will be installed
around the creek buffers to prevent erosion from entering the wetlands.
REFERENCES
Design and data methods are based on the following references:
1. Web Soils Survey 1.1
2. ICPR Computer pond routing program
3. 210-VI-TR-55, Second Ed., June 1986
4. Kernersville Unified Development Ordinance
5. North Carolina Division of Water Quality, Stormwater Best Management Practices
Manual, July 2007
6. SCS National Engineering Handbook, Section 4
7. NCDENR Erosion and Sediment Control Planning and Design Manual
OVERALL WATERSHED
Cape Fear Watershed
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SITE INFORMATION

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Appendix B
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Hydrologic Soil Group-Guilford County, North Carolina
Hydrologic Soil Group
Hydrologic Soil Group- Summary by Map Unit-Guilford County, North Carolina
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
ApB Appling sandy loam, 2 to B 30.5 28.0%
6 percent slopes
CcB Cecil sandy loam, 2 to 6 B 9.9 9.1%
percent slopes
CeB2 Cecil sandy clay loam, 2 B 4.8 4.4%
to 6 percent slopes,
eroded
Ch Chewada sandy loam C 3.3 3.1%
Co Congaree loam B 2.3 2.1%
EnD Enon fine sandy loam, 10 C 9.9 9.1%
to 15 percent slopes
MaB Madison sandy loam, 2 B 1.4 1.3%
to 6 percent slopes
McB2 Madison day loam, 2 to 6 B 16.7 15.4%
percent slopes,
eroded
McD2 Madison day loam, 10 to B 3.8 3.5%
15 percent slopes,
eroded
McE2 Madison day loam, 15 to B 25.6 23.5%
25 percent slopes,
eroded
W Water 0.6 0.5%
Totals for Area of Interest (AOI) 108.8 100.0%
UbLA Natural Resources Web Soil Survey 2.0 2/29/2008
Conservation Service National Cooperative Soil Survey Page 3 of 4

Hydrologic Soil Group-Guilford County, North Carolina
I Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive precipitation
from long-duration storms.
t The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly
wet. These consist mainly of deep, well drained to excessively drained sands or
gravelly sands. These soils have a high rate of water transmission.
r Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well drained
soils that have moderately fine texture to moderately coarse texture. These soils
' have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of water
transmission.
' Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay layer
at or near the surface, and soils that are shallow over nearly impervious material.
' These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in their
natural condition are in group D are assigned to dual classes.
' Rating Options
Aggregation Method. Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Lower

' Natural Resources Web Soil Survey 2.0 2129/2008
Conservation Service National Cooperative Soil Survey Page 4 of 4
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MA_
NCDENR Stormwater BMP Manual Chapter Revised 09-28-07

Table 3-5
Runoff curve numbers in urban areas for the SCS method (SCS, 1986)
Cover Description Curve Numbers for
Hydrologic Soil Group
Fully developed urban areas A B C D
Open Space (lawns, parks, golf courses, etc.)
Poor condition (< 50% grass cover) 68 79 86 89
Fair condition (50% to 75% grass cover) 49 69 79 84
Good condition (> 75% grass cover) . 39 61 74 80
Impervious areas:
Paved parking lots, roofs, driveways, etc. 98 98 98 98
Streets and roads:
Paved; curbs and storm sewers 98 98 98 98
Paved; open ditches 83 89 98 98
Gravel 76 85 89 91
Dirt 72 82 85 88
Developing urban areas
Newly graded areas 77 86 91 94
Pasture (< 50% ground cover or heavily grazed) 68 79 86 89
Pasture (50% to 75% ground cover or not heavily grazed) 49 69 79 84
Pasture (>75% ground cover or lightly grazed) 39 61 74 80
Meadow - continuous grass, protected from grazing and 30 58 71 78
generally mowed for hay
Brush (< 50% ground cover) 48 67 77 83
Brush (50% to 75% ground cover) 35 56 70 77
Brush (>75% ground cover) 30 48 65 73
Woods (Forest litter, small trees, and brush destroyed by 45 66 77 83
heavy grazing or regular burning)
Woods (Woods are grazed but not burned, and some forest 36 60 73 79
litter covers the soil)
Woods (Woods are protected from grazing, and litter and 30 55 70 77
brush adequately cover the soil)
Stormwater Manavement and Calmlatinna R-7
T»lcr XV 7
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Appendice
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Appendix C
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ll?

I

EROSION CONTROL DESIGN CALCULATIONS
-SEDIMENT TRAP DESIGN-
PROJECT.' PROJECT KERMES STORM.• 10 Year
JOB #: 6991.001 COMPUTED BY.• A R G
DATE.• 316108
DESIGN FOR SEDIMENT TRAP #9

Bottom Elevation 900 msl

Sediment Storage Elevation Width(ft) en h ft

Spillway Weir Elevation 902 msl F 30 60
904 msl t

To of Bern Elevation 38 76
905.5 msl Crest 46 92

To
ern Sp 104
Sediment stora ge provided: 4688 OKAY
Surface area Provided.- 4232 OKAY
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EROSION CONTROL DESIGN CALCULATIONS
-SHIMMER SEDIMENT BASIN DESIGN-
PROJECT.- PROJECT KERMES STORM: 10 Year
JOB #: 6991.001 COMPUTED BY: ARC
DATE: 316108
DESIGN FOR SKIMMER SEDIMENT BASIN #1

Bottom Elevation 900 ms/ Width ft Length(H)
Sediment Stora a Elevation 901 ms/ 20 80
Spillway Weir Elevation 902 msl F 24 96
To of Berm Elevation 903.5 mst Crest 28 112
Topof
rm 34 136
Sediment storage provided' 1952 OKAY
Surface area rovided: 3136 OKAY
Water storage 2720.00 cf
Dewatering time 1 days
Skimmer orifice diam7_Fi .64bpin
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EROSION CONTROL DESIGN CALCULATIONS
-SEDIMENT BASIN DESIGN-
PROJECT. PROJECT HERMES STORM: 10 Year
JOB #: 6991.001 COMPUTED BY: ARG
DATE: 316108
DESIGN FOR SEDIMENT BASIN #1

Bottom Elevation Width ftJ Le --
900 ms/ Bottom 70

SedimentStora a Elevation
903 ms/
Sedimerd 140

Riser Crest E/evat/on
906 ms/
Riser Crest 82 164

S /l/wa Cresf Elevation
907 msl
S Illwa Cre
t 94 188

To o/DamElevation
909 msl s
T of Dam 98
106 196
212
?r
Sediment sfora a proWded: 35556 OKAY
Surface area roWded 18656 OKAY
Water Store a 48840 cf
Dewaterin Time 1 da s
Skimmer orifice diameter 2 in

900 9800 0 0 0
903 13904 35556 0 35556
906 18656 35556 48840 84396
907 20384 35556 68360 103916
11 909 24056 35556 112800 148356

Outlet 1 diameter 30 In
Pi s/o 0.0082 (Flit
Pi /e 61 ft
Flow through oudet pi 58,22 OKAY
Outlet I Invert In 900.00
Outlet I Invert out 899.50
Requlred Are a of Holes - (As (2*It)".5)/(T*Cd*-20428J As =Surface Area of Basin =

= 0.176854 sf
P
h = Maximum head of water = 13904 sf
7 R
roposed hole tlla= 1 In
# of holes ulred= T = Time to discha a Water = 24 hrs
32 Cd = 0.6
Su
010 41.05 cfs
S !/Iwa tles! n: L=Q/ C h1.5
Coeff/clent 3
Allowable De th 0.5 k
S /l/wa len L 20 ft
S i/!wa len at bottom 7,00 h
S !l/wa width 5.00 h

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Rev. 6106
Appendices
The design of temporary sediment basins for construction sites should meet all
minimum requirements contained in Practice Standards and Spec cations:
6.61, Sediment Basin.
The following outline provides guidance in designing sediment basins to meet
those requirements.
Size, Location, and structures intended for more than 3 years of use should be designed as
Efficiency permanent structures. Procedures outlined in this section do not apply to
permanent structures. See the Dam Safety Law of 1967 and supplementary
North Carolina Administrative code title 15A.
Basic requirements for design of a sediment basin are the following:
• drainage area less than 100 acres;
• design structure life less than 3 years;
• minimum design storm, 10-yr peak runoff with minimum 1 ft freeboard;
• In High Quality Water (HQW) Zones, minimum design storm, 25-yr peak
runoff with minimum 1 foot freeboard. The sediment basin shall settle
the 40-micron particle with a minimum efficiency of at least 70% during
the 2-yr peak runoff event. See appendices beginning on pg. 8.07.13.
• maximum height shall be less than 15 feet, measured from the top of the
dam to the lowest point at the downstream toe;
• hazard classification: sudden failure should not cause loss of life or
serious property damage.
Basin location-Locate the basin so that a maximum amount of runoff from
disturbed areas can be brought into the structure. It should be accessible for
periodic cleanout and should not interfere with construction activities. When
possible delay clearing the sediment impoundment area until the dam is in
place. Deep the remaining temporary pool area undisturbed
Basin volume-Minimum volume of the basin should be 1,800 W/acre for
the disturbed area draining into the basin. Volume is measured below the
principal spillway crest. Where possible the entire drainage basin is used for
this computation, rather than the disturbed area alone, to help ensure adequate
trapping efficiency.
Trapping efficiency-For additional information see Appendices pg. 8.07.13-
8.07.42) Maximize the trapping efficiency of the basin by:
• diverting runoff from undisturbed areas away from the basin;
• limiting drainage area to increase the ratio of basin surface area to peak
inflow rate. This ratio should be 435 ftz/cfs or greater to achieve more
than 75% efficiency on most soils. Subdivide area with additional traps
and barriers to limit inflow rate and improve efficiency;
• maximizing the length-to-width ratio of the basin. Length to width should
be 2:1 to6:1;
• locating sediment inflow points as far as possible from the principal
spillway inlet;
• controlling flow at inlet points to maintain nonerosive velocities.
8.07.1

' Basin cleanout-Plan to remove sediment when approximately one half of
the basin volume has been filled. The minimum volume requirement (1,800
ft'/acre) must always be met.

' Spillway System
D
i The spillway system, consisting of a principal spillway and an emergency
spillway, should carry the peak runoff fr
10
i
h
i
i
es
gn om a
-year storm w
t
a m
n
mum
1 foot freeboard above the design water surface in the emergency spillway.
Base runoff computations on the most severe soil cover conditions expected
' during the effective life of the structure (Appendix 8.03).
PRINCIPAL SPILLWAY
The principal spillway consists of a vertical pipe riser fastened to a horizontal
t pipe barrel with watertight connectors. The horizontal conduit must extend
beyond the toe of the dam and must be st
bili
d
ll
i
a
ze
, usua
prap.
y by r
Minimum capacity-2-year peak runoff, computed for water surface at the
' emergency spillway elevation.
Crest elevation of the riser may be set no lower than the elevation of the
s
di
d
' e
ment
etention pool as a minimum.
Barrel conduit and riser-The minimum barrel conduit size allowable is
8 inches for corrugated pipe and 2 inches for smooth-walled pipe. Limit
' the maximum barrel diameter to 30 inches. The riser should have a cross-
sectional area at least 1.5 times that of the barrel. Rod and lug type connector
bands with gaskets are recommended for corrugated pipe to provide positive
' watertight connections.
Basin dewatering should be from the water surface, using a floating surface
' intake or by operating a flash board riser.
The minimum dewatering time is 24 hours, and not more than 1 foot of stage
draw-down per day.
' Trash guard-Install a trash guard on top of the riser. Afabricated cone ofsteel
rods, spaced 2 inches apart, fastened to the top of the riser is recommended.
' Protection against piping-Secure at least one watertight antiseep collar
with a minimum projecting of 1.5 feet around 12-inch or larger conduits.
Locate the collar just downstream from the centerline of the dam. A properly
designed drainage diaphragm installed around the barrel may be substituted
' for an antiseep collar.
Protection against flotation-Anchor the riser with a mass with a buoyant
i
h
' we
g
t greater than 1.1 times the weight of water displaced by the riser.
Stabilize the outlet below the barrel against erosion (Appendix 8.06).

d
8.07.2
Rev. 6106

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Rev. &W
Appendices
EMERGENCY SPILLWAY
Construct the entire flow area of the emergency spillway in undisturbed soil.
Cross section should be trapezoidal, with side slopes 3:1 or flatter. Select
vegetated lining to meet flow requirements and site conditions (Figure 8.07a)
Capacity-Design the emergency spillway for runoff from the 10-year storm
less any reduction due to flow in the principal spillway.
Inlet protection Ensure that the approach section has a slope toward the
impoundment area of not less than 2% and is flared at its entrance, gradually
reducing to the design width of the control section.
The control section should be level and straight and at least 20 ft long.
Determine the width and depth for the required capacity and site conditions.
Wide, shallow spillways are preferred because they reduce outlet velocities.
The outlet section should be straight, aligned and sloped to assure supercritical
flow with exit velocities not exceeding values acceptable for site conditions.
Outlet velocity-Ensure that the velocity of flow from the basin is nonerosive
for existing site conditions. It may be necessary to stabilize the downstream
areas or the receiving channels.
EMBANKMENT DESIGN
There should be a cutoff trench in stable soil material under the dam at the
centerline, extending up the abutments to the elevation of the emergency
spillway. The trench should be at least 2 feet deep with 1:1 side slopes, and
sufficiently wide to allow compaction by machine.
Top width-Fill height 10 feet: minimum top width 8 feet
Fill height 10-15 feet: minimum top width 10 feet
Allowment for settlement 10% of fill height.
Side slope-2.5:1 or flatter
Freeboard-minimum 1 foot between the settled top of the dam and the
design water level in the emergency spillway.
Embankment material should be a stable mineral soil, free of roots, woody
vegetation, rocks or other objectionable materials, with adequate moisture for
compaction. Place fill in 8-inch layers through the length of dam and compact
by routing constriction hauling equipment over it. Equipment must traverse
the entire surface of each layer by at least one wheel width.
EROSION CONTROL
Construct the structure to minimize the area deed Divert surface water
away from disturbed areas. Complete the embankment before clearing the
impoundment area. Stabilize the emergency spillway, embankment, and
all other disturbed areas above the crest elevation of the principal spillway
immediately after construction (Practices 6.10-6.15, Surface Stabilization).
8.07.3
1
1
1
1
1
1
1
1
1
1
n
L\
Level Portion
Berm
Approach
channel
Embankment
f
it
Plan
Water surface
Stage (Hp)
Min 20/0
Approach
channel
Crest and Control Section
1LL1illl?,l,,l?fcl, I, .
_ Flow
Exit Section
Note: Neither the location nor
alignment of the control section
has to coincide with the centerline
of the dam.
X - length of
Control exit channel
section
„t 20' tom"
level or
greater
Profile along centerline
Exit Section
3
1t-
Cross section at control section
Excavated earth spillway
b
Figure 8.07a Design of excavated earthen spillway.
8.07A
Rev. 6/06

Appendices
Safety Avoid steep side slopes. Fence basins properly and mark them
' with warning signs if trespassing is likely. Follow all State and local safety
requirements.
Design Procedure Step 1. Determine peak flow, Q105 for the basin drainage area (Appendix 8.03).
Step 2. Determine any site limitations for the sediment pool elevation, emergency
spillway or top of the dam.
' Step 3. Determine basin volumes:
• Compute minimum volume required (1800 ft'/acre disturbed).
• Specify sediment cleanout level to be marked on riser (one-half the design
volume referenced to the top of the riser) and sediment storage area to be
cleared after the dam is built.
t Step 4. Determine area and shape of basin:
• Check length/width ratio (should be 2:1 to 6:1).
' • Compute the basin surface area at principal spillway elevation.
• Check the ratio of basin surface area to peak inflow rate (should be greater
' than or equal to 435 ftz/cfs). Employ diversions with additional traps and
basins to reduce area drained.
Determine barrel capacity required for site conditions (minimum capacity for Q

10 P
is the 2-year peak runoff, Q
.
2
Step 5. Determine the principal spillway discharge capacity.
' • The combined capacities of the principal and emergency spillways must be
at least the 10-year peak flow for the entire watershed of the basin.
' • The principal spillway is analyzed for three possible limiting flow types:
Weir flow, Orifice flow, and ripe flow. The principal spillway discharge
capacity is the smallest of these three flow rates. Discharges through a
' skimmer should be disregarded during this computation. Weir, orifice and
pipe flow may be determined by the following equations:

' 1. Weir Flow: Q = CLH'•5
where:
Q = discharge in cubic feet per second (cfs)
C = weir coefficient, use 3.1 for corrugated metal pipe risers.
' L = circumference of the riser in feet
H = head above riser crest in feet
' 2. Orifice Flow: Q = CA (2gH)o.s
where:
Q = discharge in cubic feet per second (cfs)
' C = orifice coefficient, use C = 0.6 for corrugated metal pipe risers.
A = cross-sectional area of the riser pipe in square feet
9 = acceleration due to gravity, 32.2 f3/see2
H = head above riser crest in feet
I Rev. 6106
8.07.5

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D
2gh 0.5
3. Pipe Flow: Q =a 1 + Km + Kp L
where:
Q = discharge in cubic feet per second (cfs)
a = cross-sectional area of the barrel in square feet
g = acceleration due to gravity, 32.2 ft/sec2
h = head above the centerline of the outlet end of the barrel
K. = coefficient of minor losses, can be assumed to be 1.0 for
most principal spillway systems
L = barrel length in feet
Kp = pipe friction coefficient:
5087nz (See Table 8.07c for Kp values for
On common size of pipe.)
n = Manning's coefficient of roughness, use d = 0.025 for
corrugated metal pipe
n = 0.015 for reinforced concrete pipe
di = inside diameter of the barrel in inches
Select riser and barrel dimensions so that the riser has a cross-sectional area
at least 1.5 times that of the barrel. Spillway hydraulics are improved by
maximizing weir flow and minimizing orifice flow. See Table 8.07b for
recommended riser/barrel proportions.
Tahip R n7m V U. I-_ s_.. n_?.r__ ¦___ _?...__ _

Pipe Diameter
(inches) r.____-_- __._ ??
Flow Area
(square feet) ........... v...vv ¦ ¦ grow.
Manning 's Coefficient
0.015 0.025
6 0.198 0.1050 0.2916
8 0.349 0.0715 0.1987
1:0 0.545 0.0531 0.1476
12 .0785 0.0417 0.1157
14 1.069 0.0339 0.0942
15 1.23 0.0309 0.0859
16 1.40 0.0284 0.0789
18 1.77 0.0243 0.0674
21 2.41 0.0198 0.0549
24 3.14 0.0165 0.0459
27 3.98 0.0141 0.0393
30 4.91 0.0123 0.0341
36 7.07 0.0096 0.0267
42 9,62 0.0078 0.0218
48 12.57 0.0066 0.0182
54 15.90 0.0056 0.0156
60 19.64 0.0049 0.0135
8.07.6 Rev. 6ro6
Am

?U
1
d

1

10

5
1
Table 8.07b Design chart for riser outlet
Pipe
1 Pipe
'
.
Conduit Riser
(D)-in (d) - in

' 8-12
15 18
21
18 24
21 30
' 24
30
36 36
36
48
42 54
48 60
Rev. 6/06
Appendices
RISER
Select trail riser and barrel dimensions. Use the weir, orifice and pipe flow
equations to determine if the 2-year peak discharge is passed without activating
the emergency spillway. Determine riser size from Figure 8.07b. Check the
head and stage requirements. If the design stage is too high, choose larger
dimensions and recalculate. As a minimum, set the elevation of the riser at the
same elevation as the top of the sediment pool. A riser height 2 to 5 times the
barrel diameter is recommended. Select the type of trash guard.
Select a dewatering device. If a skimmer is used, refer to the manufacturers
dewatering data, or Table 6.64.b.
Step 6. Design antiseep collar.
Ensure that antiseep collars are no closer than 2 ft from a pipe joint. Collar
must project at least 1.5 ft from the pipe. Indicate watertight connections.
Step 7. Design antiflotation block.
Determine the weight of water displaced by the empty riser, and design a
block with buoyant weight 1.1 times the weight of water displaced
Step 8. Design outlet.
Determine discharge velocity from the barrel. Design outlet protection to
assure stable conditions. Riprap placement is usually necessary (Appendix
8.06).
Step 9. Design emergency spillway.
• Determine the required capacity for the emergency spillway as
Qe = Q10 - Qp (Qp 2t Qy)
• From Table 8.07e or Table 8.07f, select the width and depth of the outlet,
depending on soil conditions. In general, the wider bottom widths and
lower slopes are preferred to minimize exit velocities at supercritical
flow.
• An acceptable alternative is the use of the weir equation
Q = CLH1.5
Where this option is used, the maximum value of C should be 2.8. L
is the bottom width of the spillway at the crest, and H is the depth of
flow above the spillway crest in feet. Note: Manning's channel equation
should not be used to size the spillway crest. However, it should be used
to design the outlet channel below the spillway crest.
• The total of the emergency and principle spillway capacities must equal
or exceed the required 10-year peak discharge.
• Set the elevation of the crest of the emergency spillway a minimum of 1
foot above the crest of the riser.
Step 10. Spillway approach section.
Adjust the spillway alignment so that the control section and outlet section
are straight. The entrance width should be 1.5 times the width of the control
section with a smooth transition to the width of the control section. Approach
channel should slope toward the reservoir no less than .2%.
8.07.7

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Table 8.07c
Design Table for Vegetated Spillways Excavated in Erosion Resistant Soils
(side slopes-3 horizontal:1 vertical)
Discharge Slope Range Bottom
Q

CFS
Minimum
Percent
Maximum
Percent Width

Feet Stage
Feet
15 3.3 12.2 8 .83
3.5 18.2 12 .69
3.1 8.9 8 .97
20 3.2 13.0 12 .8T--
3.3 17.3 16 .70
2.9 7.1 8 1.09
25 3.2 9.9 12 .91
3.3 13.2 16 .79
3.3 17.2 20 .70
2.9 6.0 8 1.20
30 3.0 8.2 12 1.01
3.0 10.7 16 .88
3.3 13.8 20 .78
2.8 5.1 8 1.30
2.9 6.9 12 1.10
35 3.1 9.0 16 .94
3.1 11.3 20 .85
3.2 14.1 24 .77

40 2.7
2.9
2.9
3.1
3.1 4.5
6.0
7.6
9.7
11.9 8
12
16
20
24 1.40
1.18
1.03
.91
.83

45 2.6
2.8
2.9 4.1
5.3
R 7 8
12
4R 1.49
1.25
, nn
3.0 10.4 24 .89
2.7 3.7 8 1.57
2.8 4.7 12 1.33
50 2.8 6.0 16 1.16
2.9 7.3 20 1.03
3.1 9.0 24 .94
2.6 3.1 8 1.73
2.7 3.9 12 1.47
60 2.7 4.8 16 1.28
2 9 5.9 20 1.15
2.9 7.3 24 1.05
3.0 8.6 28 .97
2.5 2.8 8 1.88
2.6 3.3 12 1.60
70 2.6 4.1 16. 1,40
2.7 5.0 20 1.26
2.8 6.1 24 1.15
2.9 7.0 28 1.05
2.5 2.9 12 1.72
80 2.6 3.6 16 1.51
2.7 4.3 20 1.35
Discharge Slope Range Bottom Sta

Q
CFS
Minimum
Percent
Maximum
Percent
Width
Feet ge
Feet
2.8 5.2 24 1.24
80 2.8 5.9 28 1.14
2.9 7.0 32 1.06
2.5 2.6 12 1.84
2.5 3.1 16 1.61
90 2.6 3.8 20 1.45
2.7 4.5 24 1.32
2.8 5.3 28 1.22
2.8 6.1 32 1.14
2.5 2.8 16 1.71
2.6 3.3 20 1.54
100 2.6 4.0 24 1.41
2.7 4.8 28 1.30
2.7 5.3 32 121
2.8 6.1 36 1.13
2.5 2.8 20 1.71
2.6 3.2 24 1.56
120 2.7 3.8 28 1.44
2.7 4.2 32 1.34
2.7 4.8 36 126
2.5 2.7 24 1.71
2.5 3.2 28 1.58
140 2.6 3.6 32 1.47
2.6 4.0 36 1.38
2.7 4.5 40 1.30
2.5 2.7 28 1.70
2.5 3.1 32 1.58
160 2.6 3.4 36 1.49
2.6 3.8 40 1.40
2.7 4.3 44 1.33
2.4 2.7 32 1.72
180 2.4 3.0 36 1.60
2.5 3.4 40 1.51
2.6 3.7 44 1.43
2.5 2.7 36 1.70
200 2.5 2.9 40 1.60
2.5 3.3 44 1.52
2.6 3.6 48 1.45
2.4 2.6 40 1.70
220 2.5 2.9 44 1.61
2.5 3.2 48 1.53
2.5 2.6 44 1.70
240 2.5 2.9 48 1.62
2.6 3.2 52 1.54
260 2.4 2.6 48 1.70

I 2.5
E3 2.9 52 1.62
280
: 2.4 2.6 52 1.70
300 2 2.6 56 1.69

Example of Use
Given: Discharge, 0 = 87 c.f.s. Spillway slope, Exit section (from profile) = 4%
Find: Bottom width and Stage in Spillway _
Procedure: Enter table from left at 90 c.f.s. Note that Spillway slope (4%) falls within slope ranges corresponding to
bottom widths of 24, 28, and 32 ft. Use bottom width, 32 ft, to minimize velocity. State in Spillway will be
1.14 ft. "
Note: Computations based on: Roughness coefficient, n = 0.40. Maximum velocity 5.50 ft. per sec.
8.0'7.8
Rev. 6/06
a Appendices
Table 8.07d
Design Table for Vegetated Spil
lways Excavated in Very Erodible Soils
(side slopes-3 horizontal:1 vertical)
Discharge Slope Range
0 Bottom
C FS Minimum Maximum Width Stage
10 Percent Percent Feet Feet
3.5 4.7
8
68
15 3.4 4.4 12 .
69
3.4
.4
3
3 5.9 16 .
.60
20 .
3
3 3.3 12 .80
.
3
5 4.1 16 .70
.
3
3 5.3 20
.62
25 .
3
3 3.3 16 .79
.
3
5 4.0 20 .70
.
3
3 4.9
24
.64

30 .
3.3 3.3
4
0 20 .T8

3.4 .

4
7 24
.T1

3.4 .
5
5 28 .65
3.2 .
3
2 32 .61

35
3.3 .
3
9 24 .77

3.5 .

4
6 28
.71

3.5 .
5
2 32 .66
3.3 .
3
3 36 .62

40
3.4 .
3
8 28 .76
3.4 .
4
4 32 .71

3.4 .
5
0 36 .67
3.3 .
3
3 40 .64

45
3.4 .
3
8 32 .76
3.4 .
4
3 36 .71

3.4 .
4
8 40 .67
3.3 .
3
3 44 .64
50 3.3 .
3
8
4 36 .75

3.3 .
4
3 40 .71
60 3.2 .
3
2 44 .68

3.2 .
3
7 44 .75
70

3.3 .

3
3 48
72
80 3
.1 .
3.1 52
GC .75
--
Given: Discharge, Q = 38 c.f.s. a Example of Use
Find: illw
Find: Bottom width and Stage in Spill ay, Exit section (from profile) = 4%.
Procedure: Enter table from left at 40 c.f.s. Note that Spillway slope (4.0%°) falls within slope ranges corresponding
to bottom widths of 36 and 40 ft. Use wider bottom width, 40 ft., to minimize velocity. Stage In Spillway
will be 0.64 ft.
Note: Computations based on: Roughness coefficient, n = 0.40. Maximum velocity = 3.50 ft. per sec.
' Rev. 6106
8.07.9

13 Appendices
Step 11. Spillway control section
' • Locate the control section in the spillway near where it intersects the
extension of the centerline of the dam.
• Keep a level area to extend at least 20 ft upstream from the outlet end of
the control section, to ensure a straight alignment.
• Side slopes should be 3:1.
Step 12. Design spillway exit section.
• Spillway exit should align with the control section and have the same
t bottom width and side slopes.
• Slope should be sufficient to maintain supercritical flow, but make sure it
does not create erosive velocities for site conditions. (Stay within slope
ranges in appropriate design tables.)
• Extend the exit channel to a point where the water may be released without
damage.
Step 13. Size the embankment.
' • Set the design elevation of the top of the dam a minimum of 1 ft above the
water surface for the design flow in the emergency spillway.
' • Constructed height should be 10% greater than the design to allow for
settlement.
• Base top width on the design height.
• Set side slopes 2.5:1 or flatter.
• Determine depth of cutoff trench from site borings. It should extend to a
' stable, tight soil layer (a minimum of 2 ft deep).
• Select borrow site-the emergency spillway cut will provide a significant
' amount of fill.
Step 14. Erosion control
' • Locate and design diversions to protect embankment and spillway
(Practice Standards and Specifications: 6.20, Temporary Diversions).
• Select surface protection measures to control erosion (Practice Standards
' and Specifications: 6. 10, Tempor my Seeding,• 6.14, Mulching; and 6.15,
Riprap).
• Select groundcover for emergency spillway to provide protection for
design flow velocity and site conditions. Riprap stone over geotextile
fabric may be required in erodible soils or when the spillway is not in
undisturbed soils.
r Step 15. Safety.
• Construct a fence and install warning signs as needed.
&07,10 Rev. 6/06
0
1

1

Appendix D
B:1699110011drainage\6991001-DrainageReport. doc

I

Soil Curve Number
Job Project Hermes
Job No. 6991.001
Designer ARG
Date 3/6/2008
EXISTING BASINS

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F

Basin Soil Group %
B C Cover Type Percent of
& condition this cover CN
B C
EX 1 100% 0% Woods (Good) 50% 55 70 55.00
100% 0% Pasture (Good) 50% 61 74 61.00
weighted CN = 58.00
Basin Soil Group %
B C Cover Type Percent of
& condition this cover CN
B C
EX 2 25% 75% Woods (Good) 50% 55 70 66.25
75% 25% Pasture (Good) 50% 61 74 64.25
0.00
weighted CN = 65.25

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PROJECT HERMES 6991.001
PRE-DEVELOPMENT
ICPR INPUT
Nodes
A Stage/Area
V Stage/Volume
T Time/Stage
M Manhole
Basins
O Overland Flow
U SCS Unit Hydro
S Santa Barbara
Links
P Pipe
W Weir
C Channel
D Drop Structure
B Bridge
R Rating Curve
H Breach
03/06/08
T: OUTLET 1

V: E% 1
T: OUTLET 2

V: E% 2
Interconnected Channel and Pond Routing Model (ICPR) 02002 Streamline Technologies, Inc.
1
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i
PROJECT HERMES 6991.001
PRE_ DEVELOPMENT
ICPR SCHEMATIC
03/06/08
---

Basins ----------- ---
----------------------------

-----------------------
----------
Name: EX 1 Node: OUTLET 1 Status: Onsite
Group: BASE Type: SCS Unit Hydrograph
Unit Hydrograph: Uh484 Peaking Factor: 484.0
Rainfall File: Storm Duration(hrs): 0.00
Rainfall Amount(in): 0.000 Time of Conc(min): 32.00
Area(ac): 71.940 Time Shift(hrs): 0.00
Curve Number: 58.00 Max Allowable Q(cfs): 999999.000
DCIA M : 0.00
------------------

Name: EX 2 ----------------
------------------------------------------------
Node: OUTLET 2 Status: Onsite
Group: BASE Type: SCS Unit Hydrograph
Unit Hydrograph: Uh484 Peaking Factor: 484.0
Rainfall File: Storm Duration(hrs): 0.00
Rainfall Amount(in): 0.000 Time of Conc(min): 58.00
Area(ac): 75.790 Time Shift(hrs): 0.00
Curve Number: 65.25 Max Allowable Q(cfs): 999999.000
DCIA M : 0.00
Nodes
Name: OUTLET 1 Base Flow(cfs): 0.00 Init Stage(ft): 888.00
Group: BASE Warn Stage(ft): 889.00
Type: Time/Stage
Time(hrs) Stage(ft)
--------------- -----------
----
0.00 888.00
99.00 888.00
-----------------

Name: OUTLET 2 Base ---------------------------
---------------
Flow(cfs): 0.00 Init Stage(ft):
-----------
880.00
Group: BASE Warn Stage(ft): 881.00
Type: Time/Stage
Time(hrs) Stage(ft)
--------------- ----------
-----
0.00 880.00
99.00 880.00

Hydrology Simulations --- ------ -----------
Name: 001YR-24HR
Filename: B:\6k\6991\001\drainage\Pre\001YR-24HR.R32
Override Defaults: Yes
Storm Duration(hrs): 24.00
Rainfall File: Scsii-24
Rainfall Amount(in): 3.25
Time(hrs) Print Inc(min)
----- ----------
-----
24.000 5.00
------------------------

Name: 002YR-24HR -----------------------------------------

, -------
--------------
Filename: B:\6K\6991\001\DRAINAGE \PRE\002YR-24HR.R32
Override Defaults: Yes
Storm Duration(hrs): 24.00
Rainfall File: Scsii-24
Rainfall Amount (in): 3.40
Interconnected Channel and Pond Routing Model (ICPR) 02002 Streamline Technologies, Inc.
Page 1 of 4

PROJECT HERMES 6991.001
PRE-DEVELOPMENT
' ICPR SCHEMATIC
03/06/08
' Time(hrs) Print Inc(min)
------------- ---------------
24.000 5.00
--------------------------------------------------------------------------------------
' Name: 010YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\PRE\010YR-24HR.R32
Override Defaults: Yes
Storm Duration(hrs): 24.00
Rainfall File: Scsii-24
' Rainfall Amount(in): 5.15
Time(hrs) Print Inc(min)
--------------- ---------------
24.000 5.00
-------------------------------------------------------------
Name: 025YR-29HR
Filename: B:\6K\6991\001\DRAINAGE\PRE\025YR-24HR.R32
Override Defaults: Yes
Storm Duration(hrs): 24.00
Rainfall File: Scsii-24
Rainfall Amount(in): 5.60
Time(hrs) Print Inc(min)
--------------- ---------------
24.000 5.00
-----------------------------------------------------------------------------------
Name: 050YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\PRE\050YR-24HR.R32
' Override Defaults: Yes
Storm Duration(hrs): 24.00
Rainfall File: Scsii-24
Rainfall Amount(in): 6.60
' Time(hrs) Print Inc(min)
------------ ---------------
24.000 5.00
---------------------------------------------------------
Name: 100YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\PRE\100YR-24HR.R32
Override Defaults: Yes
Storm Duration(hrs): 24.00
' Rainfall File: Scsii-24
Rainfall Amount(in): 7.40
Time(hrs) Print Inc(min)
--------------- ---------------
24.000 5.00
Routing Simulations
Name: OOIYR-24HR Hydrology Sim: OOIYR-24HR
Filename: B:\6k\6991\001\drainage\Pre\001YR-24HR.I32
Execute: Yes Restart: No Patch: No
Alternative: No
Max Delta Z(ft): 1.00 Delta Z Factor: 0.00500
Time Step OptimizeP: 10.000
Start Time(hrs): 0.000 End Time(hrs): 24.00
Min Calc Time(sec): 0.0000 Max Calc Time(sec): 60.0000
' Boundary Stages: Boundary Flows:
Time(hrs) Print Inc(min)
--------------- ---------------
24.000 5.000
Group Run
--------------- -----
BASE Yes
Interconnected Channel and Pond Routing Model (ICPR) 02002 Streamline Technologies, Inc. Page 2 of 4
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PROJECT HERMES 6991.001
PRE_ DEVELOPMENT
ICPR SCHEMATIC
03/06/08
---------------------Y------------------------------------------------------
Name: 002YR-24HR Hydrology Sim: 002YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\PRE\002YR-24HR.I32
Execute: Yes Restart: No Patch: No
Alternative: No
Max Delta Z(ft): 1.00 Delta Z Factor: 0.00500
Time Step Optimizer: 10.000
Start Time(hrs): 0.000 End Time(hrs): 24.00
Min Calc Time(sec): 0.0000 Max Calc Time(sec): 60.0000
Boundary Stages: Boundary Flows:
Time(hrs)
--------- --- Print Inc(min)
--- --------

24.000 -------
5.000
Group
------------ Run
--- --

BASE ---
Yes
------------------ _____________
Name: 010YR-24HR
Hydrology Sim: 010YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\PRE\010YR-24HR.I32
Execute: Yes Restart: No Patch: No
Alternative: No
Max Delta Z(ft): 1.00 Delta Z Factor: 0.00500
Time Step Optimizer: 10.000
Start Time(hrs): 0.000 End Time(hrs)• 24.00
Min Calc Time(sec): 0.0000 Max Calc Time(sec): 60.0000
Boundary Stages: Boundary Flows:
Time(hrs). Print Inc(min)
--------------- ---------------
24.000 5.000
Group Run
--------------- -----
BASE Yes
--------------------------------------------
---------------------
Name: 025YR-24HR Hydrology Sim: 025YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\PRE\025YR-24HR.I32
Execute: Yes Restart: No Patch: No
Alternative: No
Max Delta Z(ft): 1.00 Delta Z Factor: 0.00500
Time Step Optimizer: 10.000
Start Time(hrs): 0.000 End Time(hrs): 24.00
Min Calc Time(sec): 0.0000 Max Calc Time(sec): 60.0000
Boundary Stages: Boundary Flows:
Time(hrs)
------- Print Inc(min)
--- ----------

24.000 -----
5.000
Group
------------- Run
-- --

BASE ---
Yes
----------------------------------------
------------------------------------------
Name: 050YR-24HR Hydrology Sim: 050YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\PRE\050YR-24HR.I32
Execute: Yes Restart: No Patch: No
Alternative: No
Max Delta Z(ft): 1.00 Delta Z Factor: 0.00500
Time Step Optimizer: 10.000
Interconnected Channel and Pond Routing Model (ICPR) 02002 Streamline Technologies, Inc.
Page 3 of 4
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PROJECT HERMES 6991.001
PRE-DEVELOPMENT
ICPR SCHEMATIC
03/06/08
Start Time(hrs): 0.000
Min Calc Time(sec): 0.0000
Boundary Stages:
Time(hrs)
------------ Print Inc(min)
--- --------

24.000 -------
5.000
Group
------------ Run
--- -

BASE ----
Yes
End Time(hrs): 24.00
Max Calc Time(sec): 60.0000
Boundary Flows:
-------------------------------------------------------------------------
Name: 100YR-24HR Hydrology Sim: 100YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\PRE\100YR-24HR.I32
Execute: Yes Restart: No Patch: No
Alternative: No
Max Delta Z(ft): 1.00 Delta Z Factor: 0.00500
Time Step Optimizer: 10.000
Start Time(hrs): 0.000 End Time(hrs): 24.00
Min Calc Time(sec): 0.0000 Max Calc Time(sec): 60.0000
Boundary Stages: Boundary Flows:
Time(hrs)
------------ Print Inc(min)
--- --------

24.000 -------
5.000
Group
------------ Run
--

BASE - -----
Yes
Boundary Conditions
Interconnected Channel and Pond Routing Model (ICPR) 02002 Streamline Technologies, Inc.
Page 4 of 4
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PROJECT HERMES 6991.001
PRE-DEVELOPMENT
ICPR NODE MAXIMUM
03/06/06
Max Warning Max Delta Max Surf Max Max
Name Simulation Stage Stage Stage Area Inflow Outflow
ft ft ft ft2 CfS CfS
OUTLET 1 OOIYR-24HR 888.00 889.00 0.0000 0 11
60 0
00
OUTLET 1 002YR-24HR 888.00 889.00 0.0000 0 .
14
40 .
0
00
OUTLET 1 010YR-24HR 888.00 889.00 0.0000 0 .
62.36 .
0
00
OUTLET 1 025YR-24HR 888.00 889.00 0.0000 0 78
00 .
0
00
OUTLET 1 050YR-24HR 888.00 889.00 0.0000 0 .
115
60 .
0
00
OUTLET 1 IOOYR-24HR 888.00 889.00 0.0000 0 .
147.90 .
0.00
OUTLET 2 001YR-24HR 880.00 881.00 0.0000 0 20
00 0
00
OUTLET 2 002YR-24HR 880.00 881.00 0.0000 0 .
23
05 .
0
00
OUTLET 2 OIOYR-24HR 880.00 881.00 0.0000 0 .
67
87 .
0
00
OUTLET 2 025YR-24HR 880.00 881.00 0.0000 0 .
81
21 .
0
00
OUTLET 2 050YR-24HR 880.00 881.00 0.0000 0 .
112
49 .
0
00
OUTLET 2 IOOYR-24HR 880.00 881.00 0.0000 0 .
138.76 .
0.00
Interconnected Channel and Pond Routing Model (ICPR) 02002 Streamline Technologies, Inc.
Page 1 of 1
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PROJECT HERMES 6991.001
PRE_ DEVELOPMENT
ICPR BASIN MAXIMUM
03/06/08
Simulation Basin Group Time Max Flow Max Volume Volume
hrs Cfs in ft3
001YR-24HR EX 1 BASE 12.30 11.68 0 93526
002YR-24HR EX 1 BASE 12.30 14.58 0 107961
OIOYR-24HR EX 1 BASE 12.23 62.92 1 326336
025YR-24HR EX 1 BASE 12.23 78.82 2 394299
050YR-24HR EX 1 BASE 12.23 117.10 2 558161
100YR-24HR EX 1 BASE 12.23 150.00 3 699820
OOIYR-24HR EX 2 BASE 12.63 20.11 1 174529
002YR-24HR EX 2 BASE 12.63 23.12 1 195417
010YR-24HR EX 2 BASE 12.50 68.11 2 486954
025YR-24HR EX 2 BASE 12.50 81.47 2 572772
050YR-24HR EX 2 BASE 12.50 112.78 3 774691
IOOYR-24HR EX 2 BASE 12.50 139.08 3 945213
Interconnected Channel and Pond Routing Model (ICPR) ©2002 Streamline Technologies, Inc.
Page 1 of 1

PROJECT HERMES 6991.001
PRE-DEVELOPMENT
' ICPR BASIN SUMMARY
03/06/08
Name: EX 1
Group: BASE EX 2
BASE EX 1
BASE EX 2
BASE EX 1
BASE
Simulation: 001YR-24HR OOIYR-24HR 002YR-24HR 002YR-24HR 010YR-24HR
Node: OUTLET 1 OUTLET 2 OUTLET 1 OUTLET 2 OUTLET 1
Type: SCS SCS SCS SCS SCS
Unit Hydrograph: Uh484 Uh484 Uh484 Uh484 Uh484
' Peaking Factor: 484.0 484.0 484.0 484.0 484.0
Spec Time Inc(min): 4.27 7.73 4.27 7.73 4.27
Comp Time Inc(min): 4.27 7.73 4.27 7.73 4.27
Rain File: Scsii-24 Scsii-24 Scsii-24 Scsii-24 Scsii-24
Rain Amount(in): 3.250
Duration(hrs): 24.00 3.250
24.00 3.400
24.00 3.400
24.00 5.150
24.00
Status: Onsite Onsite Onsite Onsite Onsite
TC(min): 32.00 58.00 32.00 58.00 32.00
Time Shift(hrs): 0.00 0.00 0.00 0.00 0.00
Area(ac): 71.940 75.790 71.940 75.790 71.940
Vol of Unit Hyd(in): 1 1 1 1 1
' Curve Num: 58.000 65.250 58.000 65.250 58.000
DCIA(%): 0.000 0.000 0.000 0.000 0.000
Time Max(hrs): 12.30 12.63 12.30 12.63 12.23
Flow Max(cfs): 11.68 20.11 14.58 23.12 62.92
Runoff Volume (in): 0 1 0 1 1
Runoff Volume(ft3): 93526 174529 107961 195417 326336
Name: EX 2 EX 1 EX 2 EX 1 EX 2
Group: BASE BASE BASE BASE BASE
Simulation: 010YR-24HR 025YR-24HR 025YR-24HR 050YR-24HR 050YR-24HR
Node: OUTLET 2 OUTLET 1 OUTLET 2 OUTLET 1 OUTLET 2
Type: SCS SCS SCS SCS SCS
Unit Hydrograph: Uh484 Uh484 Uh484 Uh484 Uh484
Peaking Factor: 484.0 484.0 484.0 484.0 484.0
Spec Time Inc(min): 7.73 4.27 7.73 4.27 7.73
Comp Time Inc(min): 7.73 4.27 7.73 4.27 7.73
Rain File: Scsii-24 Scsii-24 Scsii-24 Scsii-24 Scsii-24
Rain Amount(in): 5.150 5.600 5.600 6.600 6.600
Duration(hrs): 24.00 24.00 24.00 24.00 24.00
Status: Onsite Onsite Onsite Onsite Onsite
TC(min): 58.00 32.00 58.00 32.00 58.00
' Time Shift(hrs): 0.00 0.00 0.00 0.00 0.00
Area(ac): 75.790 71.940 75.790 71.940 75.790
Vol of Unit Hyd(in): 1 1 1 1 1
Curve Num: 65.250 58.000 65.250 58.000 65.250
DCIA M : 0.000 0.000 0.000 0.000 0.000
Time Max(hrs): 12.50 12.23 12.50 12.23 12.50
Flow Max(cfs): 68.11 78.82 81.47 117.10 112.78
Runoff Volume(in): 2 2 2 2 3
Runoff Volume(ft3): 486954 394299 572772 558161 774691
' Name: EX 1 EX 2
Group: BASE BASE
Simulation: 100YR-24HR 100YR-24HR
Node: OUTLET 1 OUTLET 2
Type: SCS SCS
' Unit Hydrograph: Uh484 Uh484
Peaking Factor: 484.0 484.0
Spec Time Inc(min): 4.27 7.73
Comp Time Inc(min): 4.27 7.73
Rain File:
Rain Amount(in): Scsii-24
7.400 Scsii-24
7.400
1 Duration(hrs): 24.00 24.00
Status: Onsite Onsite
TC(min): 32.00 58.00
Time Shift(hrs): 0.00 0.00
Area(ac): 71.940 75.790
' Vol of Unit Hyd(in): 1 1
Curve Num: 58.000 65.250
DCIA M : 0.000 0.000
Time Max(hrs): 12.23 12.50
Flow Max(cfs): 150.00 139.08
' Runoff Volume(in): 3 3
Runoff Volume(ft3): 699820 945213
1
t
Interconnected Channel and Pond Routing Model (ICPR) 02002 Streamline Technologies, Inc. Page 1 of 1

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001 YR-24 H R
EX 1 EX 2 Total
Time Rate Rate Rate
hrs cfs cfs cfs
0 0 0 0
0.08 0 0 0
0.17 0 0 0
0.25 0 0 0
0.33 0 0 0
0.42 0 0 0
0.5 0 0 0
0.58 0 0 0
0.67 0 0 0
0.75 0 0 0
0.83 0 0 0
0.92 0 0 0
1 0 0 0
1.08 0 0 0
1.17 0 0 0
1.25 0 0 0
1.33 0 0 0
1.42 0 0 0
1.5 0 0 0
1.58 0 0 0
1.67 0 0 0
1.75 0 0 0
1.83 0 0 0
1.92 0 0 0
2 0 0 0
2.08 0 0 0
2.17 0 0 0
2.25 0 0 0
2.33 0 0 0
2.42 0 0 0
2.5 0 0 0
2.58 0 0 0
2.67 0 0 0
2.75 0 0 0
2.83 0 0 0
2.92 0 0 0
3 0 0 0
3.08 0 0 0
3.17 0 0 0
3.25 0 0 0
3.33 0 0 0
3.42 0 0 0
3.5 0 0 0
3.58 0 0 0
3.67 0 0 0
3.75 0 0 0
3.83 0 0 0
3.92 0 0 0

002YR-24HR
EX 1 EX 2 Total
Time Rate Rate Rate
hrs cfs cfs cfs
0 0 0 0
0.08 0 0 0
0.17 0 0 0
0.25 0 0 0
0.33 0 0 0
0.42 0 0 0
0.5 0 0 0
0.58 0 0 0
0.67 0 0 0
0.75 0 0 0
0.83 0 0 0
0.92 0 0 0
1 0 0 0
1.08 0 0 0
1.17 0 0 0
1.25 0 0 0
1.33 0 0 0
1.42 0 0 0
1.5 0 0 0
1.58 0 0 0
1.67 0 0 0
1.75 0 0 0
1.83 0 0 0
1.92 0 0 0
2 0 0 0
2.08 0 0 0
2.17 0 0 0
2.25 0 0 0
2.33 0 0 0
2.42 0 0 0
2.5 0 0 0
2.58 0 0 0
2.67 0 0 0
2.75 0 0 0
2.83 0 0 0
2.92 0 0 0
3 0 0 0
3.08 0 0 0
3.17 0 0 0
3.25 0 0 0
3.33 0 0 0
3.42 0 0 0
3.5 0 0 0
3.58 0 0 0
3.67 0 0 0
3.75 0 0 0
3.83 0 0 0
3.92 0 0 0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
4 0 0 0 4 0 0 0
4.08 0 0 0 4.08 0 0 0
4.17 0 0 0 4.17 0 0 0
4.25 0 0 0 4.25 0 0 0
4.33 0 0 0 4.33 0 0 0
4.42 0 0 0 4.42 0 0 0
4.5 0 0 0 4.5 0 0 0
4.58 0 0 0 4.58 0 0 0
4.67 0 0 0 4.67 0 0 0
4.75 0 0 0 4.75 0 0 0
4.83 0 0 0 4.83 0 0 0
4.92 0 0 0 4.92 0 0 0
5 0 0 0 5 0 0 0
5.08 0 0 0 5.08 0 0 0
5.17 0 0 0 5.17 0 0 0
5.25 0 0 0 5.25 0 0 0
5.33 0 0 0 5.33 0 0 0
5.42 0 0 0 5.42 0 0 0
5.5 0 0 0 5.5 0 0 0
5.58 0 0 0 5.58 0 0 0
5.67 0 0 0 5.67 0 0 0
5.75 0 0 0 5.75 0 0 0
5.83 0 0 0 5.83 0 0 0
5.92 0 0 0 5.92 0 0 0
6 0 0 0 6 0 0 0
6.08 0 0 0 6.08 0 0 0
6.17 0 0 0 6.17 0 0 0
6.25 0 0 0 6.25 0 0 0
6.33 0 0 0 6.33 0 0 0
6.42 0 0 0 6.42 0 0 0
6.5 0 0 0 6.5 0 0 0
6.58 0 0 0 6.58 0 0 0
6.67 0 0 0 6.67 0 0 0
6.75 0 0 0 6.75 0 0 0
6.83 0 0 0 6.83 0 0 0
6.92 0 0 0 6.92 0 0 0
7 0 0 0 7 0 0 0
7.08 0 0 0 7.08 0 0 0
7.17 0 0 0 7.17 0 0 0
7.25 0 0 0 7.25 0 0 0
7.33 0 0 0 7.33 0 0 0
7.42 0 0 0 7.42 0 0 0
7.5 0 0 0 7.5 0 0 0
7.58 0 0 0 7.58 0 0 0
7.67 0 0 0 7.67 0 0 0
7.75 0 0 0 7.75 0 0 0
7.83 0 0 0 7.83 0 0 0
7.92 0 0 0 7.92 0 0 0
8 0 0 0 8 0 0 0
8.08 0 0 0 8.08 0 0 0
8.17 0 0 0 8.17 0 0 0
8.25 0 0 0 8.25 0 0 0

1

1
1

1

1

1
1
1
1
8.33 0 0 0 8.33 0 0 0
8.42 0 0 0 8.42 0 0 0
8.5 0 0 0 8.5 0 0 0
8.58 0 0 0 8.58 0 0 0
8.67 0 0 0 8.67 0 0 0
8.75 0 0 0 8.75 0 0 0
8.83 0 0 0 8.83 0 0 0
8.92 0 0 0 8.92 0 0 0
9 0 0 0 9 0 0 0
9.08 0 0 0 9.08 0 0 0
9.17 0 0 0 9.17 0 0 0
9.25 0 0 0 9.25 0 0 0
9.33 0 0 0 9.33 0 0 0
9.42 0 0 0 9.42 0 0 0
9.5 0 0 0 9.5 0 0 0
9.58 0 0 0 9.58 0 0 0
9.67 0 0 0 9.67 0 0 0
9.75 0 0 0 9.75 0 0 0
9.83 0 0 0 9.83 0 0 0
9.92 0 0 0 9.92 0 0 0
10 0 0 0 10 0 0 0
10.08 0 0 0 10.08 0 0 0
10.17 0 0 0 10.17 0 0 0
10.25 0 0 0 10.25 0 0 0
10.33 0 0 0 10.33 0 0 0
10.42 0 0 0 10.42 0 0 0
10.5 0 0 0 10.5 0 0 0
10.58 0 0 0 10.58 0 0 0
10.67 0 0 0 10.67 0 0 0
10.75 0 0 0 10.75 0 0 0
10.83 0 0 0 10.83 0 0 0
10.92 0 0 0 10.92 0 0 0
11 0 0 0 11 0 0 0
11.08 0 0 0 11.08 0 0 0
11.17 0 0 0 11.17 0 0 0
11.25 0 0 0 11.25 0 0 0
11.33 0 0 0 11.33 0 0 0
11.42 0 0 0 11.42 0 0 0
11.5 0 0 0 11.5 0 0 0
11.58 0 0 0 11.58 0 0 0
11.67 0 0.02 0.02 11.67 0 0.04 04
0
11.75 0 0.12 0.12 11.75 0 0
19 .
19
0
11.83 0.05 0.45 0.5 11.83 0.09 .
0
62 .
0
71
11.92 0.49 1.5 1.99 11.92 0.75 .
1.91 .
66
2
12 2.04 3.06 5.1 12 2.88 3.79 .
6.67
12.08 5.06 5.73 10.79 12.08 6.78 6
94 72
13
12.17 8.67 9.04 17.71 12.17 11.19 .
10
79 .
21
98
12.25 10.97 12.72 23.69 12.25 13.85 .
15
02 .
28
87
12.33 11.64 15.86 27.5 12.33 14.44 .
18
57 .
01
33
12.42 11.04 18.19 29.23 12.42 13.48 .
21.17 .
34.65
12.5 9.68 19.79 29.47 12.5 11.68 22
91 34
59
12.58 8.38 20.01 28.39 12.58 10.01 .
23.06 .
33.07

12
67 7
. .44 19.73 27.17 12.67 8.81 22.63 31.44
12.75 6.72 18.83 25.55 12.75 7.9 21.51 29.41
12.83 6.17 17.34 23.51 12.83 7.2 19.74 26.94
12.92 5.72 15.81 21.53 12.92 6.63 17.94 24.57
13 5.29 14.36 19.65 13 6.11 16.25 22.36
13.08
13.17 4.9
4.58 13.15
12
05 18.05
16
63 13.08
13
17 5.64 14.84 20.48
. . . 5.25 13.57 18.82
13.25 4.3 11.13 15.43 13.25 4.93 12.5 17.43
13.33
13.42 4.08
3.87 10.3
9.53 14.38
13.4 13.33
13
42 4.66
4
41 11.55
10
66 16.21
15
07
13.5 3.66 8.88 12.54 .
13.5 .
4.16 .
9.91 .
14.07
13.58 3.47 8.28 11.75 13.58 3.94 9.23 13.17
t 13.67 3.31 7.72 11.03 13.67 3.75 8.59 12.34
13.75 3.17 7.25 10.42 13.75 3.59 8.06 11.65
13.83 3.06 6.82 9.88 13.83 3.47 7.57 11.04
13.92 2.97 6.44 9.41 13.92 3.36 7.13 10.49
14 2.89 6.11 9 14 3.26 6.76 10.02
14.08 2.8 5.8 8.6 14.08 3.17 6.42 9.59
14.17
14.25 2.71
2.6 5.52
5.28 8.23
7
88 14.17
14
25 3.06 6.1 9.16
. . 2.94 5.82 8.76
14.33 2.5 5.04 7.54 14.33 2.82 5.56 8.38
14.42 2.41 4.82 7.23 14.42 2
71 31
5 8
02
14.5 2.33 4.6 6.93 14.5 .
2.63 .
5.07 .
7.7
14.58 2.27 4.4 6.67 14.58 2.56 4.84 7.4
14.67 2.2 4.2 6.4 14.67 2.48 4.62 7.1
' 14.75 2.12 4.02 6.14 14.75 2.39 4.42 6.81
14.83 2.04 3.86 5.9 14.83 2.29 4.24 6.53
14.92 1.97 3.71 5.68 14.92 2.22 4.08 6.3
' 15
15.08 1.93
1.92 3.59
3
47 5.52
5
39 15 2.17 3.94 6.11
. . 15.08 2.16 3.81 5.97
15.17 1.93 3.39 5.32 15.17 2.17 3.72 5.89
15.25
15.33 1.94
1.94 3.31
3.25 5.25
5
19 15.25
15
33 2.18
2 3.63 5.81
. . .18 3.56 5.74
15.42 1.91 3.19 5.1 15.42 2.15 3.5 5.65
15.5 1.86 3.14 5 15.5 2
09 44
3 53
5
15.58 1.8 3.08 4.88 15.58 .
2.02 .
3.38 .
5.4
15.67 1.75 3.02 4.77 15.67 1.96 3.31 27
5
15.75 1.72 2.96 4.68 15.75 1.92 3.25 .
5.17
1 15.83 1.7 2.9 4.6 15.83 1.91 3
18 5
09
15.92 1.7 2.85 4.55 15.92 1.9 .
3.12 .
5.02
16 1.69 2.8 4.49 16 1.89 3.07 4.96
16.08
16.17 1.67
1.67 2.76
2
72 4.43
4
39 16.08 1.87 3.02 4.89
. . 16.17 1.86 2.98 4.84
16.25 1.67 2.69 4.36 16.25 1.87 2.95 4.82
16.33
16.42 1.69
1.7 2.68
2.66 4.37
4
36 16.33
16
42 1.89 2.93 4.82
. . 1.9 2.92 4.82
16.5 1.7 2.65 4.35 16.5 1.9 2.9 4.8
16.58 1.68 2.64 4.32 16.58 1
88 2
89 4
77
16.67 1.66 2.63 4.29 16.67 .
1.86 .
2.87 .
4.73
16.75 1.63 2.61 4.24 16.75 1.83 2.85 4.68
16.83 1.61 2.58 4.19 16.83 1.79 2.83 4.62
' 16.92 1.58 2.56 4.14 16.92 1.77 2.8 4.57
1
i__
1
1
1
1
1
1
1
1
1
1
1
1
17 1.56 2.53 4.09 17 1.74 2.76 4.5
17.08 1.54 2.5 4.04 17.08 1.72 2.73 4.45
17.17 1.52 2.46 3.98 17.17 1.7 2.69 4.39
17.25 1.5 2.43 3.93 17.25 1.68 2.66 4.34
17.33 1.48 2.4 3.88 17.33 1.65 2.62 4.27
17.42 1.47 2.37 3.84 17.42 1.64 2.59 4.23
17.5 1.47 2.34 3.81 17.5 1.64 2.56 4.2
17.58 1.48 2.32 3.8 17.58 1.65 2.54 4.19
17.67 1.48 2.31 3.79 17.67 1.66 2.52 4.18
17.75 1.48 2.29 3.77 17.75 1.65 2.51 4.16
17.83 1.47 2.28 3.75 17.83 1.64 2.49 4.13
17.92 1.44 2.26 3.7 17.92 1.61 2.47 4.08
18 1.41 2.24 3.65 18 1.57 2.45 4.02
18.08 1.37 2.22 3.59 18.08 1.53 2.42 3.95
18.17 1.34 2.19 3.53 18.17 1.5 2.39 3.89
18.25 1.32 2.15 3.47 18.25 1.47 2.35 3.82
18.33 1.3 2.11 3.41 18.33 1.44 2.31 3.75
18.42 1.28 2.08 3.36 18.42 1.42 2.27 3.69
18.5 1.25 2.04 3.29 18.5 1.4 2.23 3.63
18.58 1.23 2.01 3.24 18.58 1.37 2.19 3.56
18.67 1.22 1.97 3.19 18.67 1.36 2.15 3.51
18.75 1.22 1.95 3.17 18.75 1.36 2.13 3.49
18.83 1.23 1.92 3.15 18.83 1.36 2.1 3.46
18.92 1.23 1.91 3.14 18.92 1.37 2.08 3.45
19 1.23 1.89 3.12 19 1.37 2.07 3.44
19.08 1.22 1.88 3.1 19.08 1.36 2.05 3.41
19.17 1.22 1.87 3.09 19.17 1.35 2.04 3.39
19.25 1.22 1.87 3.09 19.25 1.36 2.04 3.4
19.33 1.23 1.86 3.09 19.33 1.37 2.03 3.4
19.42 1.24 1.86 3.1 19.42 1.38 2.03 3.41
19.5 1.24 1.86 3.1 19.5 1.38 2.03 3.41
19.58 1.23 1.86 3.09 19.58 1.37 2.02 3.39
19.67 1.23 1.85 3.08 19.67 1.37 2.02 3.39
19.75 1.23 1.85 3.08 19.75 1.37 2.02 3.39
19.83 1.24 1.85 3.09 19.83 1.38 2.02 3.4
19.92 1.23 1.85 3.08 19.92 1.37 2.01 3.38
20 1.2 1.84 3.04 20 1.34 2 3.34
20.08 1.16 1.82 2.98 20.08 1.29 1.98 3.27
20.17 1.1 1.79 2.89 20.17 1.23 1.95 3.18
20.25 1.05 1.75 2.8 20.25 1.17 1.91 3.08
20.33 1.01 1.71 2.72 20.33 1.12 1.87 2.99
20.42 0.99 1.67 2.66 20.42 1.1 1.82 2.92
20.5 0.97 1.62 2.59 20.5 1.08 1.77 2.85
20.58 0.97 1.59 2.56 20.58 1.08 1.73 2.81
20.67 0.97 1.55 2.52 20.67 1.08 1.69 2.77
20.75 0.96 1.52 2.48 20.75 1.07 1.66 2.73
20.83 0.95 1.5 2.45 20.83 1.06 1.64 2.7
20.92 0.95 1.49 2.44 20.92 1.05 1.62 2.67
21 0.95 1.47 2.42 21 1.06 1.6 2.66
21.08 0.96 1.46 2.42 21.08 1.07 1.59 2.66
21.17 0.97 1.46 2.43 21.17 1.08 1.59 2.67
21.25 0.98 1.46 2.44 21.25 1.09 1.59 2.68
1
1
1
1
1
1
1
1
1
1
i
1
21.33 0.99 1.46 2.45 21.33 1.1 1.58 2.68
21.42 0.99 1.46 2.45 21.42 1.1 1.58 2.68
21.5 0.98 1.45 2.43 21.5 1.09 1.58 2.67
21.58 0.97 1.45 2.42 21.58 1.08 1.58 2.66
21.67 0.96 1.45 2.41 21.67 1.07 1.58 2.65
21.75 0.97 1.45 2.42 21.75 1.07 1.58 2.65
21.83 0.97 1.44 2.41 21.83 1.08 1.57 2.65
21.92 0.98 1.44 2.42 21.92 1.08 1.57 2.65
22 0.97 1.44 2.41 22 1.08 1.57 2.65
22.08 0.97 1.44 2.41 22.08 1.07 1.57 2.64
22.17 0.97 1.44 2.41 22.17 1.07 1.56 2.63
22.25 0.97 1.44 2.41 22.25 1.07 1.56 2.63
22.33 0.98 1.44 2.42 22.33 1.08 1.56 2.64
22.42 0.98 1.44 2.42 22.42 1.09 1.56 2.65
22.5 0.98 1.44 2.42 22.5 1.09 1.56 2.65
22.58 0.98 1.44 2.42 22.58 1.08 1.57 2.65
22.67 0.97 1.44 2.41 22.67 1.08 1.57 2.65
22.75 0.98 1.44 2.42 22.75 1.08 1.57 2.65
22.83 0.99 1.44 2.43 22.83 1.09 1.57 2.66
22.92 1 1.45 2.45 22.92 1.11 1.57 2.68
23 1.01 1.45 2.46 23 1.12 1.58 2.7
23.08 1.02 1.46 2.48 23.08 1.13 1.59 2.72
23.17 1.02 1.46 2.48 23.17 1.13 1.59 2.72
23.25 1.01 1.47 2.48 23.25 1.12 1.6 2.72
23.33 1 1.47 2.47 23.33 1.1 1.6 2.7
23.42 0.99 1.47 2.46 23.42 1.1 1.6 2.7
23.5 0.99 1.47 2.46 23.5 1.1 1.6 2.7
23.58 1 1.47 2.47 23.58 1.11 1.6 2.71
23.67 1 1.47 2.47 23.67 1.11 1.59 2.7
23.75 1 1.46 2.46 23.75 1.11 1.59 2.7
23.83 0.99 1.46 2.45 23.83 1.1 1.59 2.69
23.92 0.96 1.45 2.41 23.92 1.07 1.57 2.64
24 0.92 1.43 2.35 24 1.01 1.55 2.56
1
1
1
1
1
1
1
1
1
1
1
1
1
010YR-24HR
EX 1 EX 2 Total
Time Rate Rate Rate
hrs cfs cfs cfs
0 0 0 0
0.08 0 0 0
0.17 0 0 0
0.25 0 0 0
0.33 0 0 0
0.42 0 0 0
0.5 0 0 0
0.58 0 0 0
0.67 0 0 0
0.75 0 0 0
0.83 0 0 0
0.92 0 0 0
1 0 0 0
1.08 0 0 0
1.17 0 0 0
1.25 0 0 0
1.33 0 0 0
1.42 0 0 0
1.5 0 0 0
1.58 0 0 0
1.67 0 0 0
1.75 0 0 0
1.83 0 0 0
1.92 0 0 0
2 0 0 0
2.08 0 0 0
2.17 0 0 0
2.25 0 0 0
2.33 0 0 0
2.42 0 0 0
2.5 0 0 0
2.58 0 0 0
2.67 0 0 0
2.75 0 0 0
2.83 0 0 0
2.92 0 0 0
3 0 0 0
3.08 0 0 0
3.17 0 0 0
3.25 0 0 0
3.33 0 0 0
3.42 0 0 0
3.5 0 0 0
3.58 0 0 0
3.67 0 0 0
3.75 0 0 0
3.83 0 0 0
3.92 0 0 0
025YR-24H R
EX 1 EX 2 Total
Time Rate Rate Rate
hrs cfs cfs cfs
0 0 0 0
0.08 0 0 0
0.17 0 0 0
0.25 0 0 0
0.33 0 0 0
0.42 0 0 0
0.5 0 0 0
0.58 0 0 0
0.67 0 0 0
0.75 0 0 0
0.83 0 0 0
0.92 0 0 0
1 0 0 0
1.08 0 0 0
1.17 0 0 0
1.25 0 0 0
1.33 0 0 0
1.42 0 0 0
1.5 0 0 0
1.58 0 0 0
1.67 0 0 0
1.75 0 0 0
1.83 0 0 0
1.92 0 0 0
2 0 0 0
2.08 0 0 0
2.17 0 0 0
2.25 0 0 0
2.33 0 0 0
2.42 0 0 0
2.5 0 0 0
2.58 0 0 0
2.67 0 0 0
2.75 0 0 0
2.83 0 0 0
2.92 0 0 0
3 0 0 0
3.08 0 0 0
3.17 0 0 0
3.25 0 0 0
3.33 0 0 0
3.42 0 0 0
3.5 0 0 0
3.58 0 0 0
3.67 0 0 0
3.75 0 0 0
3.83 0 0 0
3.92 0 0 0

1
4 0 0
0
4
0
0
0
4.08 0 0 0 4.08 0 0 0
4.17 0 0 0 4.17 0 0 0
4.25 0 0 0 4.25 0 0 0
4.33 0 0 0 4.33 0 0 0
4.42 0 0 0 4.42 0 0 0
' 4.5 0 0 0 4.5 0 0 0
4.58 0 0 0 4.58 0 0 0
4.67
4.75 0
0 0
0 0
0 4.67
4 0 0 0
.75 0 0 0
4.83 0 0 0 4.83 0 0 0
4.92 0 0 0 4.92 0 0 0
' 5 0 0 0 5 0 0 0
5.08 0 0 0 5.08 0 0 0
5.17 0 0 0 5.17 0 0 0
t 5.25 0 0 0 5.25 0 0 0
5.33 0 0 0 5.33 0 0 0
5.42 0 0 0 5.42 0 0 0
5.5
5.58 0
0 0
0 0
0 5.5 0 0 0
5.58 0 0 0
5.67 0 0 0 5.67 0 0 0

' 5.75
5.83 0
0 0
0 0
0 5.75
5
83 0 0 0
. 0 0 0
5.92 0 0 0 5.92 0 0 0
6 0 0 0 6 0 0 0
' 6.08 0 0 0 6.08 0 0 0
6.17 0 0 0 6.17 0 0 0
6.25 0 0 0 6.25 0 0 0
6.33 0 0 0 6.33 0 0 0
' 6.42 0 0 0 6.42 0 0 0
6.5 0 0 0 6.5 0 0 0
6.58
6.67 0
0 0
0 0
0 6.58 0 0 0
6.67 0 0 0
6.75 0 0 0 6.75 0 0 0
6.83 0 0 0 6.83 0 0 0
' 6.92 0 0 0 6.92 0 0 0
7 0 0 0 7 0 0 0
7.08 0 0 0 7.08 0 0 0
7.17 0 0 0 7.17 0 0 0
7.25 0 0 0 7.25 0 0 0
7.33 0 0 0 7.33 0 0 0
7.42 0 0 0 7.42 0 0 0
7.5 0 0 0 7.5 0 0 0
7.58 0 0 0 7.58 0 0 0
7.67
7.75 0
0 0
0 0
0 7.67 0 0 0
7.75 0 0 0
7.83 0 0 0 7.83 0 0 0
7'92 0 0 0 7.92 0 0 0
8 0 0 0 8 0 0 0
8.08 0 0 0 8.08 0 0 0
8.17 0 0 0 8.17 0 0 0
8.25 0 0 0 8.25 0 0 0

8.33 0 0 p
8.33
0
0
0
8.42 0 0 0 8.42 0 0 0
' 8.5 0 0 0 8.5 0 0 0
8.58 0 0 0 8.58 0 0 0
8.67 0 0 0 8.67 0 0 0
' 8.75 0 0 0 8.75 0 0 0
8.83 0 0 0 8.83 0 0 0
8.92 0 0 0 8.92 0 0 0
9
9.08 0
0 0
0 0
0 9 0 0 0
9.08 0 0 0
9.17 0 0 0 9.17 0 0 0
9.25 0 0 0 9.25 0 0 0
' 9.33 0 0 0 9.33 0 0 0
9.42 0 0 0 9.42 0 0 0
9.5 0 0 0 9.5 0 0 0
' 9.58 0 0 0 9.58 0 0 0
9.67 0 0 0 9.67 0 0 0
9.75 0 0 0 9.75 0 0 0
9.83 0 0 0 9.83 0 0 0
9.92 0 0 0 9.92 0 0 0
10 0 0 0 10 0 0 0
10.08
10.17 0
0 0
0 0
0 10.08
10
1 0 0 0
.
7 0 0 0
10.25 0 0 0 10.25 0 0 0
10.33 0 0 0 10.33 0 0 0
' 10.42 0 0 0 10.42 0 0.01 01
0
10.5 0 0 0 10.5 0 0.02 .
0.02
10.58 0 0 0 10.58 0 0.03 0.03
10.67 0 0 0 10.67 0 0.07 0
07
10.75 0 0.01 0.01 10.75 0 0.12 .
0
12
10.83 0 0.02 0.02 10.83 0 0.19 .
0.19
10.92
11 0
0 0.05
0
1 0.05
0
1 10.92 0 0.3 0.3
. . 11 0 0.45 0
45
11.08 0 0.17 0.17 11.08 0 0.62 .
0
62
' 11.17
11.25 0
0 0.29
0
43 0.29
0
43 11.17
11 0 0.84 .
0.84
. . .25 0 1.1 1.1
11.33 0 0.61 0.61 11.33 0 1
39 1
39
11.42 0 0.86 0.86 11.42 0.03 .
1.75 .
1.78
' 11.5 0 1.19 1.19 11.5 0.13 2.22 2
35
11.58 0.09 1.68 1.77 11.58 0.47 2.87 .
ti 3
34
11.67 0.5 2.59 3.09 11.67 1.44 4.06 .
5.5
11.75 1.77 4.05 5.82 11.75 3.68 5.92 9
6
11.83 5.1 6.78 11.88 11.83 8.51 9.33 .
17.84
11.92 12.59 11.98 24.57 11.92 18.33 15.67 34
12
12.08 26
43
19 18.79
28
66 44.79
71
85 12 35.13 23.9 59.03
. . . 12.08 56.02 35
68 91
7
12.17 57.54 39.64 97.18 12.17 72.9 .
48
68 .
121
58
12.25
12.33 62.66
59.5 51.09
59.53 113.75
119
03 12.25
12
33 78.31 .
62.13 .
140.44
. . 73.66 71.89 145.55
12.42 51.56 65.1 116.66 12.42 63.37 78.21 141
58
12.5 42.21 68.04 110.25 12.5 51
58 81
4 .
132
98
12.58 34.48 66.58 101.06 12.58 .
41.93 .
79.38 .
121.31

m

12.67 29.03 63.69 92.72 12.67 35.13 75.7 110.83
12.75 24.98 59.05 84.03 12.75 30.09 69
97 100
06
t 12.83 21.96 53.14 75.1 12.83 26.34 .
62.82 .
89.16
12.92 19.61 47.37 66.98 12.92 23.43 55.86 79.29
13 17.61 42.16 59.77 13 20.97 49.61 70.58
13.08 15.91 37.91 53.82 13.08 18.9 44.52 63.42
13.17 14.53 34.13 48.66 13.17 17.22 40 57.22
13.25 13.41 31 44.41 13.25 15.85 36.26 52.11
' 13.33
13.42 12.48
11.66 28.25
25.73 40.73
37
39 13.33
13
42 14.72 32.98 47.7
. . 13.73 29.98 43.71
13.5 10.89 23.64 34.53 13.5 12.81 27.51 40.32
13.58 10.24 21.76 32 13.58 12.04 25
28 37
32
' 13.67 9.71 20.04 29.75 13.67 11.41 .
23.24 .
34.65
13.75 9.26 18.62 27.88 13.75 10.87 21.57 32.44
13.83 8.89 17.35 26.24 13.83 10.43 20.06 30.49
' 13.92 8.58 16.2 24.78 13.92 10.07 18.72 28.79
14 8.3 15.25 23.55 14 9.73 17.6 27.33
14.08 8.03 14.37 22.4 14.08 9.41 16.57 25.98
' 14.17
14.25 7.73
7
4 13.57
12
87 21.3
20
27 14.17 9.06 15.63 24.69
. . . 14.25 8.67 14.81 23.48
14.33 7.08 12.21 19.29 14.33 8.29 14.04 22.33

' 14.42
14.5 6.8
6.57 11.6
11.01 18.4
17
58 14.42
14
5 7.96
7
68 13.32 21.28
. . . 12.64 20.32
14.58 6.37 10.45 16.82 14.58 7.45 11.99 19.44
14.67 6.17 9.93 16.1 14.67 7.21 11
39 18
6
' 14.75 5.93 9.48 15.41 14.75 6.93 .
10.86 .
17.79
14.83 5.68 9.06 14.74 14.83 6.64 10.38 17.02
14.92 5.48 8.71 14.19 14.92 6.4 9.97 16.37
15 5.36 8.4 13.76 15 6.26 9.61 15.87
15.08 5.32 8.11 13.43 15.08 6.21 9.28 15.49
15.17 5.32 7.9 13.22 15.17 6.21 9.04 15.25
' 15.25
15.33 5.34
5.32 7.71
7
55 13.05
12
87 15.25 6.23 8.82 15.05
. . 15.33 6.21 8.63 14.84
15.42 5.25 7.41 12.66 15.42 6.12 8.47 14.59

' 15.5
15.58 5.09
4.91 7.27
7.13 12.36
12
04 15.5
15
58 5.94 8.31 14.25
. . 5.73 8.15 13.88
15.67 4.76 6.99 11.75 15.67 5.55 7.98 13.53
15.75 4.67 6.84 11.51 15.75 5.44 7
81 13
25
15.83 4.63 6.69 11.32 15.83 5.4 .
7.65 .
13.05
15.92 4.61 6.56 11.17 15.92 5.37 7.5 12.87
16 4.57 6.44 11.01 16 5.32 7.35 12.67
16.08 4.52 6.33 10.85 16.08 5.26 7.23 12.49
16.17 4.49 6.25 10.74 16.17 5.23 7.13 12.36
16.25 4.5 6.17 10.67 16.25 5.24 7.05 12.29
' 16.33
16.42 4.53
4.56 6.13
6
09 10.66
10
65 16.33 5.28 6.99 12.27
. . 16.42 5.3 6.95 12.25
16.5 4.55 6.06 10.61 16.5 5.3 6.92 12.22
16.58
16.67 4.51
4.44 6.03
5.99 10.54
10
43 16.58
16
67 5.25 6.87 12.12
. . 5.17 6.83 12
16.75 4.36 5.94 10.3 16.75 5.07 6.77 11
84
16.83 4.28 5.88 10.16 16.83 4.97 6
71 .
11
68
16.92 4.2 5.81 10.01 16.92 4.89 .
6.63 .
11.52

0

'
17 4.14 5.74 9.88 17 4.82
6.55
11
37
17.08 4.1 5.66 9.76 17.08 4.76 6
45 .
11
21
17.17 4.04 5.58 9.62 17.17 4.7 .
6.36 .
11
06
17.25 3.98 5.5 9.48 17.25 4.62 6
27 .
10
89
17.33 3.91 5.43 9.34 17.33 4.55 .
6
19 .
10
74
17.42 3.87 5.36 9.23 17.42 4.5 .
6
1 .
10
6
' 17.5 3.87 5.29 9.16 17.5 4.49 .
6
03 .
52
10
17.58 3.89 5.24 9.13 17.58 4.52 .
5.98 .
10.5

t 17.67
17.75 3.9
3.89 5.2
5
17 9.1
9
06 17.67
17 4.53 5.93 10.46
. . .75 4.52 5.89 10.41
17.83 3.85 5.13 8.98 17.83 4.47 5
85 10
32
17.92 3.78 5.09 8.87 17.92 4
39 .
5
8 .
10
19
' 18 3.69 5.04 8.73 18 .
4.28 .
5
74 .
10
02
18.08 3.6 4.98 8.58 18.08 4.17 .
67
5 .
9
84
18.17 3.51 4.91 8.42 18.17 4.07 .
5
59 .
9
66
18.25 3.44 4.83 8.27 18.25 3.99 .
5
5 .
9
49
' 18.33 3.38 4.74 8.12 18.33 3.92 .
5
4 .
9
32
18.42 3.32 4.65 7.97 18.42 3.85 .
5
3 .
9
15
18.5
18.58 3.26
3.21 4.57
4
49 7.83
7
7 18.5 3.78 .
5.2 .
8.98
. . 18.58 3.72 5
11 8
83
18.67 3.17 4.42 7.59 18.67 3.68 .
5
02 .
7
8
18.75 3.17 4.35 7.52 18.75 3.67 .
4.95 .
8.62
18.83 3.18 4.3 7.48 18.83 3.68 4.89 57
8
18.92 3.19 4.26 7.45 18.92 3.69 4.85 .
8
54
19 3.18 4.23 7.41 19 3.68 4
81 .
49
8
' 19.08 3.15 4.2 7.35 19.08 3.65 .
4
77 .
8
42
19.17 3.14 4.17 7.31 19.17 3.64 .
4
75 .
8
39
19.25 3.15 4.16 7.31 19.25 3.65 .
4
73 .
8
38
19.33 3.18 4.14 7.32 19.33 3.68 .
4
71 .
8
39
' 19.42 3.19 4.14 7.33 19.42 3.7 .
4
7 .
4
8
19.5 3.19 4.13 7.32 19.5 3.69 .
4
7 .
8
39
' 19.58
19.67 3.17
3.16 4.12
4
12 7.29
7
28 19.58 3.67 .
4.69 .
8.36
. . 19.67 3.66 4
68 34
8
19.75 3.17 4.11 7.28 19.75 3.67 .
4
68 .
8
35
19.83 3.18 4.11 7.29 19.83 3.68 .
4.67 .
8.35
' 19.92 3.16 4.1 7.26 19.92 3.66 4
65 8
31
20 3.09 4.07 7.16 20 3.57 .
4
63 .
2
8
20.08 2.96 4.03 6.99 20.08 3.43 .
4
58 .
8
01
1 20.17 2.83 3.96 6.79 20.17 3.27 .
4
5 .
7
77
20.25 2.69 3.88 6.57 20.25 3.12 .
4
41 .
7
53
20.33 2.58 3.78 6.36 20.33 2.99 .
4
3 .
7
29
20.42 2.52 3.69 6.21 20.42 2.91 .
4
19 .
7
1
' 20.5 2.49 3.59 6.08 20.5 2.88 .
4
08 .
6
96
20.58 2.48 3.5 5.98 20.58 2.86 .
3
98 .
6
84
20.67
20.75 2.47
2.45 3.43
3
36 5.9
5
81 20.67 2.86 .
3.89 .
6.75
. . 20.75 2.84 3
82 6
66
20.83 2.43 3.32 5.75 20.83 2.81 .
3
77 .
6
58
20.92 2.41 3.27 5.68 20.92 2.79 .
3.72 .
6.51
' 21 2.42 3.24 5.66 21 2.79 3
68 47
6
21.08 2.44 3.22 5.66 21.08 2.82 .
3
66 .
6
48
21.17 2.47 3.21 5.68 21.17 2.85 .
3
64 .
6
49
21.25 2.49 3.2 5.69 21.25 2.88 .
3.64 .
6.52

AM
ij

21.33 2.51 3.2 5.71 21.33 2.9 3.63 6.53
21.42 2.5 3.2 5.7 21.42 2.89 3.63 6.52
21.5 2.48 3.2 5.68 21.5 2.86 3.63 6.49
21.58 2.45 3.19 5.64 21.58 2.83 3.62 6.45
21.67 2.44 3.19 5.63 21.67 2.82 3.62 6.44
' 21.75 2.44 3.18 5.62 21.75 2.82 3.61 6.43
21.83 2.46 3.17 5.63 21.83 2.84 3.6 6.44
21.92 2.46 3.16 5.62 21.92 2.85 3.59 6.44
' 22
22.08 2.46
2.44 3.16
3
15 5.62
5
59 22 2.84 3.58 6.42
. . 22.08 2.82 3.58 6.4
22.17 2.43 3.15 5.58 22.17 2.81 3.57 6.38
22.25 2.44 3.14 5.58 22.25 2.82 3.57 6.39
' 22.33 2.46 3.14 5.6 22.33 2.84 3.57 6.41
22.42 2.47 3.14 5.61 22.42 2.85 3.57 6.42
22.5 2.47 3.14 5.61 22.5 2.85 3.57 6.42
' 22.58 2.45 3.14 5.59 22.58 2.83 3.57 6.4
22.67 2.44 3.14 5.58 22.67 2.82 3.57 6.39
22.75 2.45 3.14 5.59 22.75 2.83 3.57 6.4
22.83 2.47 3.15 5.62 22.83 2.86 3.57 6.43
22.92 2.5 3.16 5.66 22.92 2.89 3.58 6.47
23 2.53 3.17 5.7 23 2.92 3.59 6.51
' 23.08
23.17 2.55
2.54 3.18
3.19 5.73
5
73 23.08
23
17 2.94 3.61 6.55
. . 2.93 3.62 6.55
23.25 2.52 3.2 5.72 23.25 2.91 3.63 6.54
23.33 2.49 3.2 5.69 23.33 2.87 3.63 6.5
' 23.42 2.48 3.2 5.68 23.42 2.86 3.63 6.49
23.5 2.48 3.2 5.68 23.5 2.86 3.62 6.48
23.58 2.49 3.19 5.68 23.58 2.88 3.62 6.5
23.67 2.5 3.19 5.69 23.67 2.89 3.62 6.51
23.75 2.5 3.18 5.68 23.75 2.88 3.61 6.49
23.83 2.46 3.17 5.63 23.83 2.84 3.6 6.44
23.92 2.4 3.15 5.55 23.92 2.76 3.57 6.33
24 2.28 3.1 5.38 24 2.63 3.52 6.15
1
1
1
1
1
1
1
1
1
1
1
1
1
1
050YR-24HR 100YR-24HR
EX 1 EX 2 Total EX 1 EX 2 Total
Time Rate Rate Rate Time Rate Rate Rate
hrs cfs cfs cfs hrs cfs cfs cfs
0 0 0 0 0 0 0
0.08 0 0 0 0.08 0 0
0.17 0 0 0 0.17 0 0
0.25 0 0 0 0.25 0 0
0.33 0 0 0 0.33 0 0
0.42 0 0 0 0.42 0 0
0.5 0 0 0 0.5 0 0
0.58 0 0 0 0.58 0 0
0.67 0 0 0 0.67 0 0
0.75 0 0 0 0.75 0 0
0.83 0 0 0 0.83 0 0
0.92 0 0 0 0.92 0 0
1 0 0 0 1 0 0
1.08 0 0 0 1.08 0 0
1.17 0 0 0 1.17 0 0
1.25 0 0 0 1.25 0 0
1.33 0 0 0 1.33 0 0
1.42 0 0 0 1.42 0 0
1.5 0 0 0 1.5 0 0
1.58 0 0 0 1.58 0 0
1.67 0 0 0 1.67 0 0
1.75 0 0 0 1.75 0 0
1.83 0 0 0 1.83 0 0
1.92 0 0 0 1.92 0 0
2 0 0 0 2 0 0
2.08 0 0 0 2.08 0 0
2.17 0 0 0 2.17 0 0
2.25 0 0 0 2.25 0 0
2.33 0 0 0 2.33 0 0
2.42 0 0 0 2.42 0 0
2.5 0 0 0 2.5 0 0
2.58 0 0 0 2.58 0 0
2.67 0 0 0 2.67 0 0
2.75 0 0 0 2.75 0 0
2.83 0 0 0 2.83 0 0
2.92 0 0 0 2.92 0 0
3 0 0 0 3 0 0
3.08 0 0 0 3.08 0 0
3.17 0 0 0 3.17 0 0
3.25 0 0 0 3.25 0 0
3.33 0 0 0 3.33 0 0
3.42 0 0 0 3.42 0 0
3.5 0 0 0 3.5 0 0
3.58 0 0 0 3.58 0 0
3.67 0 0 0 3.67 0 0
3.75 0 0 0 3.75 0 0
3.83 0 0 0 3.83 0 0
3.92 0 0 0 3.92 0 0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
4 0 0 0 4 0 0 0
4.08 0 0 0 4.08 0 0 0
4.17 0 0 0 4.17 0 0 0
4.25 0 0 0 4.25 0 0 0
4.33 0 0 0 4.33 0 0 0
4.42 0 0 0 4.42 0 0 0
4.5 0 0 0 4.5 0 0 0
4.58 0 0 0 4.58 0 0 0
4.67 0 0 0 4.67 0 0 0
4.75 0 0 0 4.75 0 0 0
4.83 0 0 0 4.83 0 0 0
4.92 0 0 0 4.92 0 0 0
5 0 0 0 5 0 0 0
5.08 0 0 0 5.08 0 0 0
5.17 0 0 0 5.17 0 0 0
5.25 0 0 0 5.25 0 0 0
5.33 0 0 0 5.33 0 0 0
5.42 0 0 0 5.42 0 0 0
5.5 0 0 0 5.5 0 0 0
5.58 0 0 0 5.58 0 0 0
5.67 0 0 0 5.67 0 0 0
5.75 0 0 0 5.75 0 0 0
5.83 0 0 0 5.83 0 0 0
5.92 0 0 0 5.92 0 0 0
6 0 0 0 6 0 0 0
6.08 0 0 0 6.08 0 0 0
6.17 0 0 0 6.17 0 0 0
6.25 0 0 0 6.25 0 0 0
6.33 0 0 0 6.33 0 0 0
6.42 0 0 0 6.42 0 0 0
6.5 0 0 0 6.5 0 0 0
6.58 0 0 0 6.58 0 0 0
6.67 0 0 0 6.67 0 0 0
6.75 0 0 0 6.75 0 0 0
6.83 0 0 0 6.83 0 0 0
6.92 0 0 0 6.92 0 0 0
7 0 0 0 7 0 0 0
7.08 0 0 0 7.08 0 0 0
7.17 0 0 0 7.17 0 0 0
7.25 0 0 0 7.25 0 0 0
7.33 0 0 0 7.33 0 0 0
7.42 0 0 0 7.42 0 0 0
7.5 0 0 0 7.5 0 0 0
7.58 0 0 0 7.58 0 0 0
7.67 0 0 0 7.67 0 0 0
7.75 0 0 0 7.75 0 0 0
7.83 0 0 0 7.83 0 0 0
7.92 0 0 0 7.92 0 0 0
8 0 0 0 8 0 0 0
8.08 0 0 0 8.08 0 0 0
8.17 0 0 0 8.17 0 0 0
8.25 0 0 0 8.25 0 0 0
1
1
1
1
1
1
1
1
1
1
8.33 0 0 0 8.33 0 0 0
8.42 0 0 0 8.42 0 0 0
8.5 0 0 0 8.5 0 0 0
8.58 0 0 0 8.58 0 0 0
8.67 0 0 0 8.67 0 0 0
8.75 0 0 0 8.75 0 0 0
8.83 0 0 0 8.83 0 0 0
8.92 0 0 0 8.92 0 0 0
9 0 0 0 9 0 0 0
9.08 0 0 0 9.08 0 0 0
9.17 0 0 0 9.17 0 0.01 0.01
9.25 0 0 0 9.25 0 0.03 0.03
9.33 0 0 0 9.33 0 0.05 0.05
9.42 0 0 0 9.42 0 0.08 0.08
9.5 0 0 0 9.5 0 0.13 0.13
9.58 0 0 0 9.58 0 0.19 0.19
9.67 0 0.01 0.01 9.67 0 0.25 0.25
9.75 0 0.02 0.02 9.75 0 0.34 0.34
9.83 0 0.03 0.03 9.83 0 0.44 0.44
9.92 0 0.06 0.06 9.92 0 0.55 0.55
10 0 0.1 0.1 10 0 0.67 0.67
10.08 0 0.15 0.15 10.08 0 0.79 0.79
10.17 0 0.21 0.21 10.17 0 0.93 0.93
10.25 0 0.29 0.29 10.25 0 1.07 1.07
10.33 0 0.38 0.38 10.33 0 1.23 1.23
10.42 0 0.49 0.49 10.42 0 1.4 1.4
10.5 0 0.62 0.62 10.5 0.01 1.6 1.61
10.58 0 0.76 0.76 10.58 0.04 1.81 1.85
10.67 0 0.93 0.93 10.67 0.1 2.05 2.15
10.75 0 1.13 1.13 10.75 0.23 2.34 2.57
10.83 0 1.36 1.36 10.83 0.42 2.66 3.08
10.92 0.02 1.64 1.66 10.92 0.68 3.06 3.74
11 0.07 1.96 2.03 11 1.01 3.51 4.52
11.08 0.18 2.32 2.5 11.08 1.4 4 5.4
11.17 0.37 2.74 3.11 11.17 1.83 4.58 6.41
11.25 0.63 3.2 3.83 11.25 2.31 5.2 7.51
11.33 0.97 3.7 4.67 11.33 2.85 5.87 8.72
11.42 1.4 4.28 5.68 11.42 3.49 6.63 10.12
11.5 2 5.02 7.02 11.5 4.37 7.61 11.98
11.58 3.08 6.05 9.13 11.58 5.97 8.96 14.93
11.67 5.35 7.87 13.22 11.67 9.28 11.32 20.6
11.75 9.75 10.66 20.41 11.75 15.51 14.92 30.43
11.83 17.96 15.7 33.66 11.83 26.65 21.34 47.99
11.92 33.21 24.72 57.93 11.92 46.58 32.62 79.2
12 57.94 36.28 94.22 12 78.06 46.99 125.05
12.08 87.44 52.54 139.98 12.08 114.81 66.99 181.8
12.17 110.08 70.18 180.26 12.17 142.2 88.51 230.71
12.25 115.94 88.29 204.23 12.25 148.25 110.47 258.72
12.33 107.54 101.04 208.58 12.33 136.51 125.66 262.17
12.42 91.5 109.03 200.53 12.42 115.47 134.99 250.46
12.5 73.85 112.7 186.55 12.5 92.76 138.99 231.75
12.58 59.56 109.32 168.88 12.58 74.49 134.41 208.9
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
12.67 49.52 103.72 153.24 12.67 61.69 127.16 188.85
12.75 42.12 95.4 137.52 12.75 52.25 116.62 168.87
12.83 36.61 85.32 121.93 12.83 45.25 104.07 149.32
12.92 32.38 75.56 107.94 12.92 39.87 91.95 131.82
13 28.82 66.87 95.69 13 35.39 81.21 116.6
13.08 25.85 59.82 85.67 13.08 31.65 72.51 104.16
13.17 23.46 53.56 77.02 13.17 28.66 64.79 93.45
13.25 21.52 48.4 69.92 13.25 26.24 58.43 84.67
13.33 19.93 43.88 63.81 13.33 24.26 52.88 77.14
13.42 18.53 39.76 58.29 13.42 22.52 47.83 70.35
13.5 17.27 36.38 53.65 13.5 20.96 43.69 64.65
13.58 16.2, 33.35 49.55 13.58 19.65 39.99 59.64
13.67 15.34 30.58 45.92 13.67 18.59 36.6 55.19
13.75 14.6 28.31 42.91 13.75 17.68 33.85 51.53
13.83 14 26.28 40.28 13.83 16.95 31.38 48.33
13.92 13.5 24.46 37.96 13.92 16.33 29.17 45.5
14 13.03 22.96 35.99 14 15.77 27.35 43.12
14.08 12.59 21.57 34.16 14.08 15.22 25.67 40.89
14.17 12.11 20.32 32.43 14.17 14.64 24.15 38.79
14.25 11.59 19.23 30.82 14.25 14 22.83 36.83
14.33 11.07 18.2 29.27 14.33 13.38 21.58 34.96
14.42 10.62 17.24 27.86 14.42 12.82 20.43 33.25
14.5 10.25 16.34 26.59 14.5 12.37 19.34 31.71
14.58 9.94 15.47 25.41 14.58 11.99 18.3 30.29
14.67 9.62 14.68 24.3 14.67 11.6 17.35 28.95
14.75 9.23 13.99 23.22 14.75 11.13 16.53 27.66
14.83 8.84 13.35 22.19 14.83 10.66 15.78 26.44
14.92 8.52 12.83 21.35 14.92 10.27 15.15 25.42
15 8.32 12.36 20.68 15 10.03 14.59 24.62
15.08 8.26 11.93 20.19 15.08 9.95 14.09 24.04
15.17 8.26 11.61 19.87 15.17 9.95 13.7 23.65
15.25 8.28 11.33 19.61 15.25 9.97 13.36 23.33
15.33 8.25 11.08 19.33 15.33 9.93 13.07 23
15.42 8.12 10.87 18.99 15.42 9.78 12.82 22.6
15.5 7.89 10.67 18.56 15.5 9.49 12.58 22.07
15.58 7.6 10.46 18.06 15.58 9.14 12.33 21.47
15.67 7.36 10.24 17.6 15.67 8.85 12.07 20.92
15.75 7.22 10.02 17.24 15.75 8.68 11.8 20.48
15.83 7.15 9.8 16.95 15.83 8.6 11.55 20.15
15.92 7.11 9.6 16.71 15.92 8.55 11.31 19.86
16 7.05 9.42 16.47 16 8.47 11.1 19.57
16.08 6.97 9.26 16.23 16.08 8.38 10.91 19.29
16.17 6.93 9.13 16.06 16.17 8.32 10.75 19.07
16.25 6.94 9.02 15.96 16.25 8.33 10.62 18.95
16.33 6.98 8.95 15.93 16.33 8.39 10.53 18.92
16.42 7.02 8.89 15.91 16.42 8.42 10.46 18.88
16.5 7 8.85 15.85 16.5 8.41 10.41 18.82
16.58 6.94 8.79 15.73 16.58 8.33 10.34 18.67
16.67 6.83 8.73 15.56 16.67 8.2 10.27 18.47
16.75 6.7 8.66 15.36 16.75 8.04 10.19 18.23
16.83 6.57 8.57 15.14 16.83 7.88 10.08 17.96
16.92 6.45 8.47 14.92 16.92 7.74 9.96 17.7
1
1
1
1
1
1
1
1
1
1
1
1
17 6.36 8.36 14.72 17 7.63 9.83 17.46
17.08 6.28 8.24 14.52 17.08 7.53 9.69 17.22
17.17 6.2 8.13 14.33 17.17 7.43 9.55 16.98
17.25 6.09 8.01 14.1 17.25 7.3 9.41 16.71
17.33 5.99 7.9 13.89 17.33 7.18 9.28 16.46
17.42 5.93 7.79 13.72 17.42 7.11 9.15 16.26
17.5 5.92 7.7 13.62 17.5 7.1 9.04 16.14
17.58 5.95 7.62 13.57 17.58 7.13 8.96 16.09
17.67 5.97 7.56 13.53 17.67 7.15 8.88 16.03
17.75 5.95 7.51 13.46 17.75 7.13 8.82 15.95
17.83 5.89 7.46 13.35 17.83 7.05 8.76 15.81
17.92 5.78 7.4 13.18 17.92 6.92 8.69 15.61
18 5.64 7.32 12.96 18 6.75 8.59 15.34
18.08 5.49 7.23 12.72 18.08 6.57 8.49 15.06
18.17 5.36 7.12 12.48 18.17 6.41 8.36 14.77
18.25 5.24 7 12.24 18.25 6.28 8.22 14.5
18.33 5.15 6.88 12.03 18.33 6.17 8.07 14.24
18.42 5.07 6.75 11.82 18.42 6.06 7.92 13.98
18.5 4.97 6.62 11.59 18.5 5.95 7.77 13.72
18.58 4.89 6.5 11.39 18.58 5.84 7.63 13.47
18.67 4.83 6.4 11.23 18.67 5.78 7.5 13.28
18.75 4.82 6.3 11.12 18.75 5.77 7.4 13.17
18.83 4.84 6.23 11.07 18.83 5.79 7.3 13.09
18.92 4.85 6.17 11.02 18.92 5.8 7.23 13.03
19 4.83 6.12 10.95 19 5.78 7.17 12.95
19.08 4.8 6.07 10.87 19.08 5.74 7.12 12.86
19.17 4.78 6.04 10.82 19.17 5.71 7.08 12.79
19.25 4.79 6.01 10.8 19.25 5.73 7.05 12.78
19.33 4.83 5.99 10.82 19.33 5.77 7.03 12.8
19.42 4.85 5.98 10.83 19.42 5.8 7.01 12.81
19.5 4.84 5.97 10.81 19.5 5.79 7 79
12
19.58 4.82 5.96 10.78 19.58 5.75 6.99 .
12.74
19.67 4.8 5.95 10.75 19.67 5.73 6.98 12.71
19.75 4.81 5.94 10.75 19.75 5.75 6.96 12.71
19.83 4.83 5.93 10.76 19.83 5.77 6.95 12.72
19.92 4.8 5.91 10.71 19.92 5.73 6.93 12.66
20 4.68 5.88 10.56 20 5.59 6
89 12.48
20.08 4.5 5.82 10.32 20.08 5.37 .
6.81 12.18
20.17 4.29 5.72 10.01 20.17 5.12 6.7 11
82
20.25 4.08 5.6 9.68 20.25 4.87 6
56 .
43
11
20.33 3.92 5.46 9.38 20.33 4.68 .
6.4 .
11.08
20.42 3.81 5.32 9.13 20.42 4.55 6.23 10.78
20.5 3.77 5.18 8.95 20.5 4.49 6.06 10.55
20.58 3.75 5.05 8.8 20.58 4.48 5.92 4
10
20.67 3.74 4.94 8.68 20.67 4.46 5.79 .
10.25
20.75 3.71 4.85 8.56 20.75 4.43 5.68 10.11
20.83 3.67 4.78 8.45 20.83 4.38 5
6 9
98
20.92 3.65 4.72 8.37 20.92 4.35 .
5
53 .
9
88
21 3.66 4.67 8.33 21 4.36 .
5.47 .
9.83
21.08 3.69 4.64 8.33 21.08 4.4 5
43 9
83
21.17 3.73 4.62 8.35 21.17 4.45 .
5
41 .
9.86
21.25 3.77 4.61 8.38 21.25 4.49 .
5.4 9.89
21.33 3.79 4.61 8.4 21.33 4.52 5.4 9.92
21.42 3.78 4.61 8.39 21.42 4.51 5.39 9.9
21.5 3.75 4.6 8.35 21.5 4.47 5.39 9.86
21.58 3.71 4.6 8.31 21.58 4.42 5.38 9.8
21.67 3.68 4.59 8.27 21.67 4.39 5.37 9.76
21.75 3.69 4.57 8.26 21.75 4.39 5.35 9.74
21.83 3.71 4.56 8.27 21.83 4.42 5.34 9.76
21.92 3.72 4.55 8.27 21.92 4.44 5.32 9.76
22 3.71 4.54 8.25 22 4.42 5.31 9.73
22.08 3.69 4.53 8.22 22.08 4.39 5.3 9.69
22.17 3.67 4.52 8.19 22.17 4.37 5.29 9.66
22.25 3.68 4.52 8.2 22.25 4.39 5.29 9.68
22.33 3.71 4.52 8.23 22.33 4.42 5.29 9.71
22.42 3.73 4.52 8.25 22.42 4.44 5.29 9.73
22.5 3.72 4.52 8.24 22.5 4.43 5.29 9.72
22.58 3.7 4.52 8.22 22.58 4.4 5.29 9.69
22.67 3.68 4.52 8.2 22.67 4.38 5.28 9.66
22.75 3.69 4.52 8.21 22.75 4.4 5.28 9.68
22.83 3.73 4.52 8.25 22.83 4.44 5.29 9.73
22.92 3.77 4.53 8.3 22.92 4.49 5.3 9.79
23 3.81 4.55 8.36 23 4.54 5.32 9.86
23.08 3.83 4.57 8.4 23.08 4.56 5.34 9.9
23.17 3.83 4.58 8.41 23.17 4.56 5.36 9.92
23.25 3.79 4.59 8.38 23.25 4.51 5.37 9.88
23.33 3.75 4.59 8.34 23.33 4.46 5.37 9.83
23.42 3.72 4.59 8.31 23.42 4.43 5.37 9.8
23.5 3.73 4.59 8.32 23.5 4.44 5.36 9.8
23.58 3.75 4.58 8.33 23.58 4.47 5.35 9.82
23.67 3.77 4.57 8.34 23.67 4.48 5.35 9.83
23.75 3.76 4.57 8.33 23.75 4.47 5.34 9.81
23.83 3.7 4.55 8.25 23.83 4.41 5.32 9.73
23.92 3.6 4.51 8.11 23.92 4.29 5.27 9.56
24 3.42 4.45 7.87 24 4.07 5.2 9.27

The proposed of this section is to show the sizing of the outlet control structure and the
' staging of the wet pond to make sure it does not overtop the top of bank.

Appendix E
I B:\6991\001\drainage\6991001-DrainageReport.doc

0

1

N
t ?
U
C E
LO LO
N
ch
I
Co
C
O
L
N II
UI
N F
T E
E
C
E

Soil Curve Number
Job Project Hermes
Job No. 6991.001
Designer ARG
Date 3/6/2008
L
PROPOSED BASINS
1
1
1
1
1
1
1
1
1
1
nasin 0011 k7roup -/,
B C
PR 1 100% 0% Cover Type Percent of
& condition this cover
Pavement 100% CN
B C
98 98

98
0

weighted CN = 98.00

1
1
1

1
Nodes
A Stage/Area
V Stage/Volume
T Time/Stage
M Manhole
' Basins
0 Overland Flow
U SCS Unit Hydro
S Santa Barbara
Links
P Pipe
W Weir
C Channel
D Drop Structure
B Bridge
' R Rating Curve
H Breach

1

1
r

PROJECT HERMES 6991.001
POST-DEVELOPMENT
ICPR SCHEMATIC
03/13/08
Interconnected Channel and Pond Routing Model QCPR) 02002 Streamline Technologies, Inc.

1

I
PROJECT HERMES 6991.001
POST-DEVELOPMENT
ICPR INPUT
03/13/08
-------------
Basins ------------ ------------------------------ ------------------------

---------------
Name: PR 1 Node: WET POND 1 Status: Onsite
Group: BASE Type: SCS Unit Hydrograph
Unit Hydrograph: Uh484 Peaking Factor: 484.0
Rainfall File: Storm Duration(hrs): 0.00
Rainfall Amount(in): 0.000 Time of Conc(min): 20.00
Area(ac): 98.000 Time Shift(hrs): 0.00
Curve Number: 84.83 Max Allowable Q(cfs): 999999.000
DCIA(%): 0.00
-------------------------

Nodes
___________

------------
Name: OUTLET 1 Base Flow(cfs): 0.000 Ini t Stage(ft): 890.000
Group: BASE War n Stage(ft): 890.000
Type: Time/Stage
Time(hrs) --Stage(ft)
--------------- 0.00 890.000
99.00 890.000
Name: WET POND 1
Group: BASE
Type: Stage/Area

1
1
1

------------------------------- ---
Base Flow(cfs): 0.000 Init Stage(ft): 909.000
Warn Stage(ft): 915.500
Stage(ft) Area(ac)
--------------- -----------
----
909.000 2.9100
910.000 3.2400
911.000 3.3500
912.000 3.4500
913.000 3.5600
914.000 3.6600
915.000 3.7700
916.000 3.8800
916.500 3.9300
------------------------------------

Drop Structures -------------------------------
----------
--------------
------
Name: OUTLET STR 1 From Node: WET POND 1 Length(ft): 150.00
Group: BASE To Node: OUTLET 1 Count: 1
UPSTREAM DOWNSTREAM Friction Equation: Average Conveyance
Geometry: Circular Circular Solution Algorithm: Automatic
Span(in): 30.00 30.00 Flow: Both
Rise(in): 30.00 30.00 Entrance Loss Coef: 0.000
Invert(ft): 900.000 890.000 Exit Loss Coef: 0.000
Manning's N: 0.013000 0.013000 Outlet Ctrl Spec: Use do or tw
Top Clip(in): 0.000 0.000 Inlet Ctrl Spec: Use do
Bot Clip(in): 0.000 0.000 Solution Incs: 10
Upstream FHWA Inlet Edge Description:
Circular Concrete: Square edge w/ headwall
Downstream FHWA Inlet Edge Description:
Circular Concrete: Square edge w/ headwall
*** Weir 1 of 3 for Drop Structure OUTLET SIR 1 ***
TABLE
Count: 1 Bottom Clip(in): 0.000
Type: Vertical: Mavis Top Clip(in). 0.000
Flow: Both Weir Disc Coef: 3.200
Geometry: Circular Orifice Disc Coef: 0.600
Interconnected Channel and Pond Routing Model (ICPR) ©2002 Streamline Technologies, Inc.
Page 1 of 5
M
t
1
1
1
1
1
1
1
1
1
1
1
1
1
PROJECT HERMES 6991.001
POST-DEVELOPMENT
ICPR INPUT
03/13/08
Span(in): 6.00 Invert(ft): 909.000
Rise(in): 6.00 Control Elev(ft): 909.000
*** Weir 2 of 3 for Drop Structure OUTLET SIR 1 ***
TABLE
Count: 4 Bottom Clip(in): 0.000
Type: Vertical: Mavis Top Clip(in): 0.000
Flow: Both Weir Disc Coef: 3.200
Geometry: Rectangular Orifice Disc Coef: 0.600
Span(in): 36.00 Invert(ft): 912.250
Rise(in): 6.00 Control Elev(ft): 912.250
*** Weir 3 of 3 for Drop Structure OUTLET STR 1 ***
TABLE
Count: 1 Bottom Clip(in): 0.000
Type: Horizontal Top Clip(in): 0.000
Flow: Both Weir Disc Coef: 3.200
Geometry: Rectangular Orifice Disc Coef: 0.600
Span(in): 36.00 Invert(ft): 912.750
Rise(in): 36.00 Control Elev(ft): 912.750
--------------
-------------------------
----------------------------------------------------------
Weirs
---------- ------
Name: EMER WEIR From Node: WET POND 1
Group: BASE To Node: OUTLET 1
Flow: Both Count: 1
Type: Vertical: Fread Geometry: Trapezoidal
Bottom Width(ft): 35.00
Left Side Slope(h/v): 3.00
Right Side Slope(h/v): 3.00
Invert(ft): 914.500
Control Elevation (ft): 914.500
Struct Opening Dim(ft): 9999.00
TABLE
Bottom Clip(ft): 0.000
Top Clip(ft): 0.000
Weir Discharge Coef: 3.200
Orifice Discharge Coef: 0.600
------------------------------------------------------------------------------------------
=====Hydrology-Simulations
_____________
Name: 001YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\POST\001YR-24HR.R32
Override Defaults: Yes
Storm Duration(hrs): 24.00
Rainfall File: Scsii-24
Rainfall Amount(in): 3.25
Time(hrs) Print Inc(min)
----------- --------------
120.000 10.00
--------------------------------------------------------------
Name: 002YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\POST\002YR-24HR.R32
Override Defaults: Yes
Storm Duration(hrs): 24.00
Rainfall File: Scsii-24
Rainfall Amount(in): 3.40
Time(hrs) Print Inc(min)
--------------- ---------------
24.000 5.00
------------------------------------------------------- -----------------
Name: 010YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\POST\010YR-24HR.R32
Override Defaults: Yes
Storm Duration(hrs): 24.00
Interconnected Channel and Pond Routing Model (ICPR) ©2002 Streamline Technologies, Inc.
Page 2 of 5

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PROJECT HERMES 6991.001
POST-DEVELOPMENT
ICPR INPUT
03/13/08
Rainfall File: Scsii-24
Rainfall Amount(in): 5.15
Time(hrs) Print Inc(min)
------------
24.000 5.00
---------------------------------------------------------------------
Name: 025YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\POST\025YR-24HR.R32
Override Defaults: Yes
Storm Duration(hrs): 24.00
Rainfall File: Scsii-24
Rainfall Amount(in): 5.60
Time(hrs) Print Inc(min)
--------------- ---------------
24.000 5.00
--------------------------------------------------------------------
Name: 050YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\POST\050YR-24HR.R32
Override Defaults: Yes
Storm Duration(hrs): 24.00
Rainfall File: Scsii-24
Rainfall Amount(in): 6.60
Time(hrs) Print Inc(min)
--------------- ---------------
24.000 5.00
----------------------------------------------------------------------
Name: 100YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\POST\100YR-24HR.R32
Override Defaults: Yes
Storm Duration(hrs): 24.00
Rainfall File: Scsii-24
Rainfall Amount(in): 7.60
Time(hrs) Print Inc(min)
--------------- ---------------
24.000 5.00
Routing Simulations
Name: 001YR-24HR Hydrology Sim: 001YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\POST\001YR-24HR.132
Execute: Yes Restart: No Patch: No
Alternative: No
Max Delta Z(ft): 1.00 Delta Z Factor: 0.00500
Time Step Optimizer: 10.000
Start Time(hrs): 0.000 End Time(hrs): 120.00
Min Calc Time(sec): 0.0000 Max Calc Time(sec): 60.0000
Boundary Stages: Boundary Flows:
Time(hrs) Print Inc(min)
- -----------

120.000 ----
10.000
Group
------------ Run
-

BASE -- -----
Yes
--------------------------------------------------------------------------------------------------
Name: 002YR-24HR Hydrology Sim: 002YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\POST\002YR-24HR.I32
Execute: Yes Restart: No Patch: No
Alternative: No
Max Delta Z(ft): 1.00 Delta Z Factor: 0.00500
Time Step Optimizer: 10.000
Interconnected Channel and Pond Routing Model (ICPR) 02002 Streamline Technologies, Inc.
Page 3 of 5
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Start Time(hrs): 0.000
Min Calc Time (sec): 0.0000
Boundary Stages:
PROJECT HERMES 6991.001
POST-DEVELOPMENT
ICPR INPUT
03/13/08
End Time(hrs): 24.00
Max Calc Time sec): 60.0000
Boundary Flows:
Time(hrs) Print Inc(min)
--------------- --------------
-
24.000 5.000
Group Run
--------------- -----
BASE Yes
-------------------
Name: 010YR-24HR Hydrology -------------------------------------------------------
Sim: OIOYR-24HR
Filename: B:\6K\6991\001\DRAINAGE\POST\OIOYR-24HR.I32
Execute: Yes Restart: No Patch: No
Alternative: No
Max Delta Z(ft): 1.00 Delta Z Factor: 0.00500
Time Step Optimizer: 10.000
Start Time(hrs): 0.000 End Time(hrs): 24.00
Min Calc Time(sec): 0.0000 Max Calc Time(sec): 60.0000
Boundary Stages: Boundary Flows:
Time(hrs) Print Inc(min)
----------
24.000 5.000
Group Run
--------------- -----
BASE Yes
----------------------------------------------------------------------------------------------
Name: 025YR-24HR Hydrology Sim: 025YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\POST\025YR-24HR.I32
Execute: Yes Restart: No Patch: No
Alternative: No
Max Delta Z(ft): 1.00 Delta Z Factor: 0.00500
Time Step Optimizer: 10.000
Start Time(hrs): 0.000 End Time(hrs): 24.00
Min Calc Time(sec): 0.0000 Max Calc Time(sec): 60.0000
Boundary Stages: Boundary Flows:
Time(hrs) ---
-------------- - Print Inc(min)
-
5.000
Group
------------- Run
-
BASE - -----
Yes

Name: -------------------------
050YR-24HR Hydrology ------------------------ -------------
Sim: 050YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\POST\050YR-24HR.I32
Execute: Yes Restart: No Patch: No
Alternative: No
Max De lta Z(ft): 1.00 Delta Z Factor: 0.00500
Time Step Optimizer: 10.000
Start Time(hrs): 0.000 End Time(hrs): 24.00
Min Calc Time(sec): 0.0000 Max Calc Time(sec): 60.0000
Bounda ry Stages: Boundary Flows:
Time(hrs) Print Inc(min)
--------------- ---------------
24.000 5.000
Interconnected Channel and Pond Routing Model (ICPR) 02002 Streamline Technologies, Inc.
Page 4of5

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PROJECT HERMES 6991.001
POST-DEVELOPMENT
ICPR INPUT
03/13/08
Group Run
--------------- -----
BASE Yes
-----------------------------------------------------------------------------------------
Name: 100YR-24HR Hydrology Sim: 100YR-24HR
Filename: B:\6K\6991\001\DRAINAGE\POST\100YR-24HR.I32
Execute: Yes Restart: No Patch: No
Alternative: No
Max Delta Z(ft): 1.00 Delta Z Factor: 0.00500
Time Step Optimizer: 10.000
Start Time(hrs): 0.000 End Time(hrs): 24.00
Min Calc Time(sec): 0.0000 Max Calc Time(sec): 60.0000
Boundary Stages: Boundary Flows:
Time(hrs) Print Inc(min)
- ----- ------ ------------ --
24.000 5.000
Group Run
--------------- -----
BASE Yes
-------------------
------------------------------------------------------------------------- -
Boundary Conditions ___-------- -------
----------------------------------
Interconnected Channel and Pond Routing Model (ICPR) 02002 Streamline Technologies, Inc.
Page 5 of 5

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PROJECT HERMES 6991.001
POST-DEVELOPMENT
ICPR NODE MAXIMUM
03/13/08
Max Warning Max Delta Max Surf Max Max
Name Simulation Stage Stage Stage Area Inflow Outflow
ft ft ft ft2 CfS CfS
OUTLET 1 001YR-24HR 890.00 890.00 0.0000 0 4.98 0.00
OUTLET 1 002YR-24HR 890.00 890.00 0.0000 0 6.52 0.00
OUTLET 1 OIOYR-24HR 890.00 890.00 0.0000 0 66.13 0.00
OUTLET 1 025YR-24HR 890.00 890.00 0.0000 0 86.70 0.00
OUTLET 1 050YR-24HR 890.00 890.00 0.0000 0 140.23 0.00
OUTLET 1 100YR-24HR 890.00 890.00 0.0000 0 245.72 0.00
WET POND 1 001YR-24HR 912.44 915.50 0.0050 152412 169.05 4.98
WET POND 1 002YR-24HR 912.50 915.50 0.0050 152680 197.20 6.52
WET POND 1 010YR-24HR 913.66 915.50 0.0050 157930 355.54 66.13
WET POND 1 025YR-24HR 914.03 915.50 0.0050 159561 396.74 86.70
WET POND 1 050YR-24HR 914.90 915.50 0.0050 163765 488.37 140.23
WET POND 1 100YR-24HR 915.51 915.50 0.0050 166661 579.77 245.72
Interconnected Channel and Pond Routing Model (ICPR) ©2002 Streamline Technologies, Inc.
Page 1 of 1
PROJECT HERMES 6991.001
POST-DEVELOPMENT
ICPR LINK MAXIMUM
03/13/08
Max Max Max Max
Name Simulation Flow Delta Q US Stage DS Stage
CfS CfS ft ft
EMER WEIR 001YR-24HR 0.00 0.000 912.44 890.00
EMER WEIR 002YR-24HR 0.00 0.000 912.50 890.00
EMER WEIR 010YR-24HR 0.00 0.000 913.66 890.00
EMER WEIR 025YR-24HR 0.00 0.000 914.03 890.00
EMER WEIR OSOYR-24HR 29.64 -0.387 914.90 890.00
EMER WEIR 100YR-24HR 121.33 -0.878 915.51 890.00
OUTLET SIR 1 001YR-24HR 4.98 0.034 912.44 890.00
OUTLET STR 1 002YR-24HR 6.52 0.056 912.50 890.00
OUTLET STR 1 010YR-24HR 66.13 -0.266 913.66 890.00
OUTLET STR 1 025YR-24HR 86.70 -0.368 914.03 890.00
OUTLET STR 1 050YR-24HR 110.59 -0.347 914.90 890.00
OUTLET STR 1 100YR-24HR 124.39 0.303 915.51 890.00
Interconnected Channel and Pond Routing Model (ICPR) ©2002 Streamline Technologies, Inc. Page 1 of I
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PROJECT HERMES 6991.001
POST-DEVELOPMENT
ICPR BASIN MAXIMUM
03/13/08
Simulation Basin Group Time Max Flow Max Vol ume Volume
hrs Cfs in ft3
001YR-24HR PR 1 BASE 12.09 185.54 2 634962
002YR-24HR PR 1 BASE 12.09 198.88 2 680715
010YR-24HR PR 1 BASE 12.09 358.14 3 1239884
025YR-24HR PR 1 BASE 12.09 399.54 4 1388703
050YR-24HR PR 1 BASE 12.09 491.62 5 1723846
100YR-24HR PR 1 BASE 12.09 583.55 6 2063445
Interconnected Channel and Pond Routing Model (ICPR) 02002 Streamline Technologies, Inc.
Page 1 of 1

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PROJECT HERMES 6991.001
POST-DEVELOPMENT
ICPR BASIN SUMMARY
03/13/08
Name: PR 1 PR 1 PR 1 PR 1 PR 1
Group: BASE BASE BASE BASE BASE
Simulation: 001YR-24HR 002YR-24HR 010YR-24HR 025YR-24HR 050YR-24HR
Node: WET POND 1 WET POND 1 WET POND 1 WET POND 1 WET POND 1
Type: SCS SCS SCS SCS SCS
Unit Hydrograph: Uh484 Uh484 Uh484 Uh484 Uh484
Peaking Factor: 484.0 484.0 484.0 484.0 484.0
Spec Time Inc(min): 2.67 2.67 2.67 2.67 2.67
Comp Time Inc(min): 2.67 2.67 2.67 2.67 2.67
Rain File: Scsii-24 Scsii-24 Scsii-24 Scsii-24 Scsii-24
Rain Amount(in): 3.250 3.400 5.150 5.600 6.600
Duration(hrs): 24.00 24.00 24.00 24.00 24.00
Status: Onsite Onsite Onsite Onsite Onsite
TC(min): 20.00 20.00 20.00 20.00 20.00
Time Shift(hrs): 0.00 0.00 0.00 0.00 0.00
Area(ac): 98.000 98.000 98.000 98.000 98.000
Vol of Unit Hyd(in): 1 1 1 1 1
Curve Num: 84.830 84.830 84.830 84.830 84.830
DCIA(%): 0.000 0.000 0.000 0.000 0.000
Time Max(hrs): 12.09 12.09 12.09 12.09 12.09
Flow Max(cfs): 185.54 198.88 358.14 399.54 491.62
Runoff Volume(in): 2 2 3 4 5
Runoff Volume(ft3): 634962 680715 1239884 1388703 1723846
Name: PR 1
Group: BASE
Simulation: 100YR-24HR
Node: WET POND 1
Type: SCS
Unit Hydrograph: Uh484
Peaking Factor: 484.0
Spec Time Inc(min): 2.67
Comp Time Inc(min): 2.67
Rain File: Scsii-24
Rain Amount(in): 7.600
Duration(hrs): 24.00
Status: Onsite
TC(min): 20.00
Time Shift(hrs): 0.00
Area(ac): 98.000
Vol of Unit Hyd(in): 1
Curve Num: 84.830
DCIA(%): 0.000
Time Max(hrs): 12.09
Flow Max(cfs): 583.55
Runoff Volume(in): 6
Runoff Volume(ft3): 2063445
I Interconnected Channel and Pond Routing Model (ICPR) 02002 Streamline Technologies, Inc.
Page 1 of 1

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PROJECT HERMES 6991.001
POST-DEVELOPMENT
ICPR TIME v FLOW
03/13/08
6
U
3
0
LL
Simulation 001YR-24HR
4
2
0L
0
20 40 60 80
Timefts)
EMER WEIR
OUTLET STR 1
100 120 140
Interconnected Channel and Pond Routing Model (ICPR) ©2002 Streamline Technologies, Inc.

11

1
Appendix F
B:16991\001\drainage\6991001-DrainageReport.doc

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11

11

Permit
(to be provided by DWQ)
e warE
??? o?,o ROG
r
NCDENR Y
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
WET DETENTION BASIN SUPPLEMENT
This form must be filled out, printed and submitted.
The Required Items Checklist (Part 111) must be printed, filled out and submitted along with all of the required information.
Project name PROJECT HERMES
Contact person ANDY SCALES
Phone number 704.697.5916
Date 316/2008
Drainage area number PR 1

Site Characteristics ;ry
Drainage area 3,695,200.00 ftz
Impervious area 3,621,290.00 ftz
% impervious 98.00 %
Design rainfall depth 3.25 in
Storage Volume: Non-SR Waters
Minimum volume required ft3
Volume provided ft3
Storage Volume: SR Waters
1-yr, 24-hr runoff depth in
Pre-development 1-yr, 24-hr runoff ft3
Post-development 1-yr, 24-hr runoff ft3
Minimum volume required ft3
Volume provided ft3
Peak Flow Calculations
1-yr, 24-hr rainfall depth 3.25 in
Rational C, pre-development 58, 65.25 (unitless)
Rational C, post-development 98.00 (unitless)
Rainfall intensity:1-yr, 24-hr storm in/hr
Pre-development 1-yr, 24-hr peak flow 29.47 ft3/sec
Post-development 1-yr, 24-hr peak flow 14.64 ft3/sec
Pre/Post 1-yr, 24-hr peak flow control -14.83 ft3/sec
Basin Elevations
Basin bottom elevation 900.00 ft
Sediment cleanout elevation 902.25 ft
Bottom of shelf elevation 908.00 ft
Permanent pool elevation 909.00 ft
SHWT elevation ft
Top of shelf elevation 910.00 It
Temporary pool elevation 912.25 ft
Form SW401-Wet Detention Basin-Rev.4
Parts I. 8 II. Design Summary, Page 1 of 2
Permit No.
(to be provided by DWQ)
SA/DA ratio 2.11 (unitless)
Volume and Surface Area Calculations

Surface area at the bottom of shelf 85,822.00 ft2
' Volume at the bottom of shelf 607,785.00 ft3
Permanent pool, surface area required 77,972.00 ft2
' Permanent pool, surface area provided
Permanent pool volume 126,760.00
698,781.00 ft2
ft3 OK
Average depth for SA/DA tables 5.51 It OK
Surface area at the top of shelf 141,134.00 ft2
Volume at the top of shelf 133,729.00 ft3
' Forebay volume 165,825.00 ft3
Forebay % of permanent pool volume 23.73 % Must be approx. 20%, Adjust pond dimensions
Temporary pool, surface area provided 145,926.00 ft2
Drawdown Calculations
Treatment volume drawdown time 5.00 days OK
Treatment volume discharge rate 0.98 ft31s
-development
Pre 1-yr, 24-hr discharge
29.47
ft3)s
OK
' Post-development 1-yr, 24-hr discharge 14.64 ft3(S OK
Additional Information
Diameter of orifice 6 in
' Design TSS removal 85 %
Basin side slopes 3.00 :1 OK
etated shelf
Veg slope
10.00
1
OK
' Vegetated shelf width 20.00 ft OK
Length of flowpath to width ratio 3.00 :1 OK
gth
Len to width ratio
1.25
:1
Too short; increase ratio to at least 1.5:1
h
Tras rack for overflow & orifice?
Y
(Y or N)
OK
' Freeboard provided 1.14 ft OK
Vegetated filter provided? Y (Y or N) OK

' orded drainage
Rec easement provided?
Capures all runoff at ultimate build-out?
Y
Y
(Y or N)
(Y or N)
OK
OK
Drain mechanism for maintenance or emergencies DIP DRAINS IN FOREBAY AND MAIN POND

Forth SW401-Wet Detention Basin-Rev.4 Parts I. & II. Design Summary, Page 2 of 2

M VA
NCDENR

Permit
(to be provided by DWQ)
O??F W A7F?pG
? r
P "C
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
WET DETENTION BASIN SUPPLEMENT
This form must be filled out, printed and submitted.
The Required Items Checklist (Part Ill) must be printed, filled out and submitted along with all of the required information.
.._-._
Project name
Contact person
Phone number
Date
Drainage area number
N ..
PROJECT HERMES
ANDY SCALES
704.697.5916
3/6/2008
PR 1
Site Characteristics
Drainage area 3,695,200.00 ft2
Impervious area 3,621,290.00 ft2
% impervious
Design rainfall depth 98.00
3.25 %
in
Storage Volume: Non-SR Waters
Minimum volume required
Volume provided ft3
ft3
Storage Volume: SR Waters
1-yr, 24-hr runoff depth
Pre-development 1-yr, 24-hr runoff in
ft3
Post-development 1-yr, 24-hr runoff ft 3
Minimum volume required ft 3
Volume provided ft 3
Peak Flow Calculations
1-yr, 24-hr rainfall depth 3.25 in
Rational C, pre-development
Rational C, post-development 58, 65.25
98.00 (unitless)
(unitless)
Rainfall intensity: 1-yr, 24-hr storm in/hr
Pre-development 1-yr, 24-hr peak flow 29.47 ft3/sec
Post-development 1-yr, 24-hr peak flow 4.98 ft3/sec
Pre/Post 1-yr, 24-hr peak flow control -24.49 ft3/sec
Basin Elevations
Basin bottom elevation
Sediment cleanout elevation 900.00
902.25 ft
ft
Bottom of shelf elevation 908.00 ft
Permanent pool elevation
SHWT elevation 909.00 ft
ft
Top of shelf elevation 910.00 ft
Temporary pool elevation 912.25 ft
1

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1 Form SW401-Wet Detention Basin-Rev.4 Parts I. & H. Design Summary, Page 1 of 2
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Permit No.
(to be provided by DWQ)
Volume and Surface Area Calculations
SA/DA ratio 2.11 (unitless)
Surface area at the bottom of shelf 85,822.00 ftz
Volume at the bottom of shelf 607,785.00 fta
Permanent pool, surface area required 77,972.00 ftz
Permanent pool, surface area provided 126,760.00 ft O K
Permanent pool volume 698,781.00 fta
Average depth for SA/DA tables 5.51 ft OK
Surface area at the top of shelf 141,134.00 ft2
Volume at the top of shelf 133,729.00 fta
Forebay volume 165,825.00 fta
Forebay % of permanent pool volume 23.73 % Must be approx. 20%, Adjust pond dimensions
Temporary pool, surface area provided 145,926.00 ftz
Drawdown Calculations
Treatment volume drawdown time 5.00 days OK
Treatment volume discharge rate 0.98 fta/s
Pre-development 1-yr, 24-hr discharge 29.47 fta/s OK
Post-development 1-yr, 24-hr discharge 14.64 fta/s OK
Additional Information
Diameter of orifice 6 in
Design TSS removal 85 %
Basin side slopes 3.00 :1 OK
Vegetated shelf slope 10.00 :1 OK
Vegetated shelf width 20.00 it OK
Length of flowpath to width ratio 3.00 :1 OK
Length to width ratio 125 :1 Too short, increase ratio to at least 1.5:1
Trash rack for overflow & orifice? Y (Y or N) OK
Freeboard provided 1.14 ft OK
Vegetated filter provided? Y (Y or N) OK
Recorded drainage easement provided? Y (Y or N) OK
Capures all runoff at ultimate build-out? Y (Y or N) OK
Drain mechanism for maintenance or emergencies DIP DRAINS IN FOREBAY AND MAIN POND
Form SW401-Wet Detention Basin-Rev.4 Parts I. & II. Design Summary, Page 2 of 2
NCDENR Stormwater BMP Manual Chapter Revised 09-28-07
10. Wet Detention Basin
Wet Detention Basin WA T--I-- 'IfU ,,

E

NCDENR Stormwater BMP Manual Chapter Revised 09-28-07
Major Design Elements
' 1 Sizing shall take into account all runoff at ultimate build-out, including off-site drainage.
2 Vegetated slopes shall be no steeper than 3:1.
' 3 BMP shall be located in a recorded drainage easement with a recorded access easement to
a public ROW.
4 Basin discharge shall be evenly distributed across a minimum 30 feet long vegetative filter
strip unless it is designed to remove 90% TSS. (A 50-ft filter is required in some locations.)
t 5 If any portion is used for S&EC during construction must be cleaned out and returned to
design state.
6 The design storage shall be above the permanent pool.
' Dischar
e rate followin
a 1-inch rainf
orar
h
t
ll
l
t
l
th
ll
d
d
7 g
g
y
a
s
a
comp
emp
e
y
raw
e
e
own
storage volume between 2 and 5 days.
' 8 The average depth of the permanent pool shall be a minimum of 3 feet.
9 Permanent pool surface area shall be determined using Tables 10-1,10-2,10-3, and 10-4.

' 1 0 The flow within the pond shall not short-circuit the pond.
11 BMP shall be designed with a forebay.
' 12 Basin side slopes shall be stabilized with vegetation above the permanent pool level.
13 The pond shall be designed with side slopes no steeper than 3:1.
' The basin shall be desi
ned with
ration
ffi
i
t
di
t
t
f
ll
14 g
su
c
en
se
or proper ope
men
s
orage to a
ow
between scheduled cleanouts.
t
' 15 BMP shall not be located to produce adverse impacts on water levels in adjacent wetlands.
A minimum 10-foot wide vegetated shelf shall be installed around the perimeter. The
' 16 inside edge of the shelf shall be 6" below the permanent pool elevation; the outside edge
of the shelf shall be 6" above the permanent pool elevation.
17 The forebay volume should be about 20% of the total permanent pool volume, leaving
about 80% of the design volume in the main pool.
18 Freeboard shall be a minimum of 1 foot above the maximum stage of the basin.
Wet Detention Basin -in-9

' NCDENR Stormwater BMP Manual Chapter Revised 09-28-07
' 10.1. General Characteristics and Purpose
In wet detention basins, a permanent pool of standing water is maintained by the riser-
' the elevated outlet of the wet detention basin (see Figure 10-1). Water in the permanent
pool mixes with and dilutes the initial runoff from storm events. Wet detention basins
fill with stormwater and release most of the mixed flow over a period of a few days,
t slowly returning the basin to its normal depth.
Runoff generated during the early phases of a storm usually has the highest
' concentrations of sediment and dissolved pollutants. Because a wet detention basin
dilutes and settles pollutants in the initial runoff, the concentration of pollutants in the
runoff released downstream is reduced. Following storm events, pollutants are removed
' from water retained in the wet detention basin. Two mechanisms that remove pollutants
in wet detention basins include settling of suspended particulates and biological uptake,
or consumption of pollutants by plants, algae, and bacteria in the water. However, if the
' basin is not adequately maintained (e.g., by periodic excavation of the captured
sediment), storm flows may re-suspend sediments and deliver them to the stream.

1
Wet Detention Basin I rLa
Figure 10-1
Permanent Pool of Water in Wet Detention Basin

J

NCDENR Stormwater BMP Manual Chapter Revised 09-28-07
Wet detention basins are applicable in residential, industrial, and commercial
developments where enough space is available. Figures 10-2a and 10-2b are schematic
plan views showing the basic elements of a wet detention basin. Wet detention basins
are sized and configured to provide significant removal of pollutants from the incoming
stormwater runoff. The permanent pool of water is designed for a target TSS removal
efficiency according to the size and imperviousness of the contributing watershed.
Above this permanent pool of water, wet detention basins are also designed to hold the
runoff volume required by the stormwater regulations, and to release it over a period of
2 to 5 days. As a result, most of the suspended sediment and pollutants attached to the
sediment settle out of the water. In addition, water is slowly released so that
downstream erosion from smaller storms is lessened.
Main Pond
-80% Perm. Pool Volume
Optional flow-path
eloagation -herms
-1__ 1M
Wet Detention Ravin
in A
Figure 10-2a
Basic Wet Detention Basin Elements: Plan View

NCDENR Stormwater BMP Manual
Chapter Revised 09-28-07
Figure 10-2b
Basic Wet Detention Basin Elements: Cross-Section

outlet above
Vegetated*

11

1

North Carolina rules require that a wet detention basin must be designed by a licensed
professional. Further, the designer must subsequently certify that he inspected the
facility during construction, that the BMP was built in accordance with the approved
plans, and that the system complies with the requirements of the rules.
To obtain a permit to construct a wet detention basin in North Carolina, the wet
detention basin must meet all of the regulation-based Major Design Elements listed in
the beginning of this section.
To receive the pollutant removal rates listed in the front of this section, the wet detention
basin engineering design must, at a minimum, meet all of the Major Design Elements
listed in the beginning of this section. Additional regulation-based requirements, and
additional good engineering practice requirements, may be required by DWQ.
Pollutant Removal Rates
Standard pollutant rates are provided in Table 4-2 in Section 4.0. Construction of a wet
detention basin also passively lowers nutrient loading since it is counted as pervious
surface when calculating nutrient loading. Further enhancing the passive reduction of
Wet Detention Basin
10-5
T..1.. I)M'7
10.2. Meeting Regulatory Requirements

NCDENR Stormwater BMP Manual Chapter Revised 09-28-07
nutrient loading is the fact that the surface area of any permanent water surface
contributes no nutrient runoff (an export coefficient of 0.0 lb/ac/yr).
Volume Control Calculations
Calculations for the temporary pool volume draw-down time are provided in Section
3.4.
If this BMP comes close to meeting your regulatory requirements, but is not exactly
what is desired for your site, then these similar types of BMPs might be worth
considering: stormwater wetlands, dry extended detention basins.
If this BMP will not meet the regulatory requirements of the site by itself, but is desired
to be part of the stormwater treatment solution for the site for other reasons, the
following stormwater controls can be used in conjunction to provide enhanced pollution
removal rates or volume control capabilities: sand filters, bioretention, infiltration
devices, porous pavement, filter strips, grassed swales, and restored riparian buffers.
10.3. Design
10.3.1. Converting Sediment and, Erosion Control Devices
Wet detention basins are typically part of the initial site clearing and grading activities
' and, are often used as sediment basins dunn construction of the u stre
g P am
deve opment..The NCI) NR Erosion and Sediment ConMol Planning and Design Manual
' contains ,design requirements for sediment basins required during construction. A
sedirtentbasin typically does not include all the engineering features of a wet detention
basin, and the design engineer must insure that the wet detention basin includes all the
' features identified in this section, including the full sizing as a wet detention basin. If the
wet detention basin is used as a sediment trap during construction, all sediment
deposited during construction must be removed, erosion features must be repaired, and
' the vegetated shelf must be restored, before operation as a stormwater BUT begins.

WPt Dofrnffinn Racin
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' NCDENR Stormwater BMP Manual Chapter Revised 09-28-07

' 10.3.2. Siting Issues
Because large storage volumes are
needed to achieve extended detention times, wet

' detention basins require larger land areas than many other BMPs. Wet detention basins
may not be suitable for projects with ver
li
it
d
il
bl
l
y
m
e
ava
a
e
and. Permanent retaining
walls may be used to obtain the required design volumes while reducing the footprint
that would otherwise be required for earthen construction. Retaining walls utilized to
' contain the permanent pool must not reduce the required 10' width of the vegetated
shelf, and must not extend to a top elevation above the lowest point of the vegetated

' shelf. Retaining walls utilized to contain the temporary pool must not reduce the
required 10' width of the ve
etated
h
lf
d
g
s
e
, an
must not be in contact with the
stormwater stored up to the temporary pool elevation. Two retaining walls may be
' used, as shown in Figure 10-3. Or, the design may be altered to contain only one of the
two shown.
Wet detention basins may not be constructed on intermittent streams, on perennial
' streams, or in jurisdictional wetlands. Large wet detention basins that include a wetland
fringe and are abandon
d i
l
h
e
n p
ace wit
out first being drained and regraded may be
regulated as wetlands under the provisions of Sections 401 and 404 of the Clean Water
' Act.
Further, DWQ will require an engineering demonstration that the installation of a wet
detention basin adjacent to wetlands will not produce adverse affects on the wetlands
water level.
The use of stormwater wet detention basins discharging to cold-water streams capable
' of supporting trout may be prohibited. Stormwater wet detention basins located in such
watersheds should be augmented with engineering measures to significantly reduce or
eliminate thermal impacts.

Figure 10-3
Alternative Wet Pond Design: Retaining Wall Option

vvet uetenuon tsasm
10-7
Tuly 2007

' NCDENR Stormwater BMP Manual Chapter Revised 09-28-07
' 10.3.3. Pretreatment and Inflow
' Forebays are required on all inlets to a wet detention basin. Chapter 5 Common BMP
Design Elements addresses the engineering design requirements for forebays. A
properly engineered forebay can concentrate large particle-size sediment for easier
' removal, and can dissipate the incoming flow energy prior to the stormwater entering
the main part of the BMP. The dissipation of incoming flow energy reduces re-
suspension of settled material in the main pool, and it reduces the likelihood of erosion
' features within the BMP. Also, the forebay itself should be configured for energy
dissipation within the forebay to avoid re-suspension of large-particle settled material
previously captured in the forebay. One of several engineering means of energy
' dissipation is to have the inlet pipe submerged below the permanent forebay pool level,
provided that the inlet placement does not serve to re-suspend previously captured
sediment.
1
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1
DWQ requires that the design volume for the forebay be approximately 20% of the total
calculated permanent pool volume. The main pool of the permanent pool would then
account for approximately 80% of the design volume.
10.3.4. Length, Width (Area), Depth, Geometry
DWQ uses Driscoll's model (US EPA, 1986) to determine the appropriate surface area of
the permanent pool for wet detention basins to achieve the required TSS removal rate.
The surface area required can be determined using the permanent pool Surface Area to
Drainage Area ratio (SA/DA) for given levels of impervious cover and basin depths as
outlined in Tables 10-1,10-2, and 10-3. The tabulated SA/DA ratios are reported as
percentages. Table 10-1 is based upon 85 percent TSS removal efficiency in the
Mountain and Piedmont regions of North Carolina, while Table 10-2 is based upon
85 percent removal efficiencies for the Coastal region. Table 10-3 presents the design
SA/DA ratio for 90 percent TSS removal efficiencies in the Coastal region.
Depth is an important engineering design criterion because most of the pollutants are
removed through settling. Very shallow basins may develop currents that can re-
suspend materials; on the other hand, very deep wet detention basins can become
thermally stratified and/or anoxic and release pollutants back into the water. North
Carolina regulations establish 3 feet as the minimum average depth. Further, DWQ
requires that the engineering design incorporate a minimum additional depth of one
foot for sediment storage. An average pool depth of 3 feet to 7.5 feet is recommended as
optimal. Further, DWQ requires that the engineering design include a minimum
freeboard of one foot above the maximum stage of the basin.
The permanent pool average depth is defined as the permanent pool volume divided by
the permanent pool surface area.
wet uetention Basin 10,8
Tnly 2( M
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INCDENR Stormwater BMP Manual Chapter Revised 09-28-07

Table 10-1
Surface Area to Drainage Area Ratio for Permanent Pool Sizing to Achieve 85 Percent T5S
Pollutant Removal Efficien in the Mountain and Piedmont Regions, Adapted from Driscoll, 1986
Percent Permanent Pool Average Depth (ft)
Impervious
Cover 3.0 4.0 5.0 6.0 7.0 8.0 9.0
10% 0.59 0.49 0.43 0.35 0.31 0.29 0.26
20% 0.97 0.79 0.70 0.59 0.51 0.46 0.44
30% 1.34 1.08 0.97 0.83 0.70 0.64 0.62
40% 1.73 1.43 1.25 1.05 0.90 0.82 0.77
50% 2.06 1.73 1.50 1.30 1.09 1.00 0.92
60% 2.40 2.03 1.71 1.51 1.29 1.18 1.10
70% 2.88 2.40 2.07 1.79 1.54 1.35 1.26
80% 3.36 2.78 2.38 2.10 1.86 1.60 1.42
90% 3.74 3.10 2.66 2.34 2.11 1.83 1.67
Table 10-2
Surface Area to Drainage Area Ratio for Permanent Pool Sizing to Achieve 85 Percent TSS
Pollutant Removal Efficiency in the Coastal Region, Adap ted from Driscoll, 1986
Percent Permanent Pool Average Depth (ft)
Impervious
Cover 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5'
10% F 0.8 0.7 0.6 0.5 0 0 0 0 0
20% 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0
6 0.5
30% 12 1.9 1.8 1.6 1.5 1.3 1.2 .
1.0 0.9
40% 3.4 3.0 2.6 2.4 2.1 1.9 1.6 1.4 1.1 1.0
50% 7 3.3 3.0 2.7 2.4 2.1 1.8 1.5 1.3
60% 5.0 4.5 3.8 3.5 3.2 2.9 2.6 2.3 2.0 1.6
70% 6.0 5.2 4.5 4.1 3.7 3.3a 2.9 2.5 2.1 1.8
80% 6.8 6.0 5.2 4.7 4.2 3.7 3.2 2.7 2.2 2.0
90% 7.5 6.5 5.8 5.3 4.8 4.3 3.8 3.3 2.8 1.3
100% 8.2 7.4 6.8 6.2 5.6 10 4.4 3.8 3.2 2.6
Table 10-3
Surface Area to Drainage Area Ratio for Permanent Pool Sizing to Achieve 90 Percent TSS
Pollutant Removal Efficiencv in the Mrn.Htai" mid P;VAMn I. ue..;...... A a .....a L.._- 'I noc
Perceztit
Impervious
Cover

10

3.5

4.0 Permanent Pool Average Depth (ft)

4.5 5.0 5.5 &0 6.5 .7.0

7.5

8.0

8.5

9.0
10% 0.9 0.8 0.8 0.7 0.6 0.6 0.5 0.5 0.5 0.5 0.4 0.4 0.4
20% 1.5 1.3 1.1 1.0 1.0 0.9 0.9 0.9 0.8 0.8 0.8 0.7 0.7
30% 1.9 1.8 1.7 1.5 1.4 1.4 1.3 1.1 1.0 1.0 1.0 0.9 0.9
40% 2.5 2.3 2.0 1.9 1.8 1.7 1.6 1.6 1.5 1.4 1.3 1.2 1.1
50% 3.0 '2.8 2.5 2.3 2.0 1.9 1.9 1.8 1.7 1.6 1.6 1.5 1.5
60% 3.5 3.2 2.8 2.7 2.5 2.4 2.2 2.1 1.9 1.9 1.8 1.8 1.7
70% 4.0 3.7 3.3 3.1 2.8 2.7 2.5 2.4 2.2 2.1 2.0 2.0 1.9
80% 4.5 4.1 3.8 3.5 3.3 3.0 2.8 2.7 2.6 2.4 2.3 2.1 2.0
90% 5.0 4.5 4.0 3.8 3.5 3.3 3.0 2.9 2.8 2.7 2.6 2.5 2.4
wet Detention Basin 10-9

NCDENR Stormwater BMP Manual Chapter Revised 09-28-07
Table 10-4
' Surface Area to Drainage Area Ratio for Permanent Pool Sizing to Achieve 90 Percent ISS
Pollutant Removal Efficienc y in the Coastal Region, Adap ted from Driscoll, 1986
Percent
Impervious Permanent Pool Average Depth (ft)
Cover 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5'
10% 1.3 1.0 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1
20% 2.4 2.0 1.8 1.7 1.5 1.4 1.2 1.0 0.9 0.6
30% 3.5 3.0 2.7 2.5 2.2 1.9 1.6 1.3 1.1 0.8
40% 4.5 4.0 3.5 3.1 2.8 2.5 2.1 1.8 1.4 1.1
50% 5.6 5.0 4.3 3.9 3.5 3.1 2.7 2.3 1.9 1.5
60% 7.0 6.0 5.3 4.8 4.3 3.9 3.4 2.9 2.4 1.9
70% 8.1 7.0 6.0 5.5 5.0 4.5 3.9 3.4 2.9 2.3
80% 9.4 8.0 7.0 6.4 5.7 5.2 4.6 4.0 3.4 2.8
90% 10.7 9.0 7.9 7.2 6.5 5.9 5.2 4.6 3.9 3.3
100% 12 10.0 8.8 8.1 7.3 6.6 5.8 5.1 4.3 3.6
The engineering design of a wet detention basin must include a 10-foot-wide (minimum)
vegetated shelf around the full perimeter of the basin. The inside edge of the shelf shall
be no deeper than 6" below the permanent pool level, and the outside edge shall be 6"
above the permanent pool level. For a 10' wide shelf, the resulting slope is 10:1. With
half the required shelf below the water (maximum depth of 6 inches), and half the
required shelf above the water, the vegetated shelf will provide a location for a diverse
' population of emergent wetland vegetation that enhances biological pollutant removal,
provides a habitat for wildlife, protects the shoreline from erosion, and improves
sediment trap efficiency. A 10' wide shelf also provides a safety feature prior to the
' deeper permanent pool.
' Short-circuiting of the stormwater must be prevented. The most direct way of
minimizing short-circuiting is to maxin„ze the length of the flow path between the inlet
and the outlet: basins with long and narrow shapes can maximize the length of the flow
' path. Long and narrow but irregularly shaped wet detention basins may appear more
natural and therefore may have increased aesthetic value. If local site conditions prohibit
a relatively long, narrow facility, baffles may be placed in the wet detention basin to
' lengthen the stormwater flow path as much as possible. Baffles must extend to the
temporary pool elevation or higher. A minimum length-to-width ratio of 1.5:1 is
required, but a flow path of at least 3:1 is recommended. Basin shape should minimize
dead storage areas, and where possible the width should expand as it approaches the
' outlet.
Although larger wet detention basins typically remove more pollutants, a threshold size
seems to exist above which further improvement of water quality by sedimentation is
negligible. The water treatment volume within a wet detention basin is calculated as the
' total volume beneath the permanent pool water level, and above the sediment storage
volume, including any such volume within the forebay.
1
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Wet Detention Basin 10-10 T„1., 7nm

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NCDENR Stormwater BMP Manual Chapter Revised 09-28-07
10.3.5. Temporary Storage Volume
In addition to the permanent pool volume, the basin must also have temporary pool
storage to provide volume control during storm events. This temporary pool storage
volume is located above the permanent pool, and below the 1-foot minimum freeboard
requirement. The required temporary pool volume must be calculated as specified in
Section 3.3.1.
10.3.6. Sediment Accumulation
North Carolina rules require that the wet detention basin shall be sized with an
additional volume to account for sediment deposition between clean-out intervals
(typically 5 to 15 years). DWQ requires that engineering designs for wet detention
basins include at least one additional foot of depth for sediment storage in addition to
the permanent pool volume. It is important that operation and maintenance agreements
specify that the forebay and the wet pond be cleaned out as soon as the extra sediment
storage depth is exhausted. A benchmark for sediment removal should be established
to assure timely maintenance. Calculations for volumes and sediment accumulation are
provided in Section 3.0.
10.3.7. Plant and Landscape Requirements
The design of a wet detention basin is not complete without a detailed landscaping plan.
The planting plan must be prepared by a qualified design professional licensed in North
Carolina (see Chapter 6 for landscape plan requirements). The landscaping plan for a
stormwater wet detention basin should provide specifications for the selection of
vegetation, its installation, and the post installation care for the vegetated shelf, the 3:1
side slopes, the vegetative filter strip, and the immediately surrounding areas.
Wet detention basins should incorporate several diverse species of shallow water and
shallow land [wetland] vegetation on the vegetated shelf. Sections 6.2.2 and 6.2.3
discuss the planting requirements for shallow water and shallow land areas. Table 9-1
contains a list of appropriate plant species. Diversity in species increases the robustness
of the vegetated shelf by increasing the chances that some species will survive minor
changes in the permanent pool water level. This vegetation enhances pollutant removal,
protects the shoreline from erosion, and increases safety by discouraging people from
entering the basin. A wide range of potential plant species is available for this purpose.
On the tops of berms and on the exterior slopes of containment berms, maintain turf
grass in access areas; Centipede grass is recommended. Well-maintained grass stabilizes
the embankment, enhances access to the facility, and makes inspection and other
maintenance much easier. Because many plants release phosphorus in the winter when
they die off, wet detention ponds used for phosphorous control should be planted with
broad-leaf evergreen trees and shrubs.
Where trees and shrubs are part of the planting plan, they should be selected to
maximize shading, primarily along the south, east, and west sides of the basin. This has
wet Uetention Basin
10-11
iuly 2007

' NCDENR Stormwater BMP Manual Chapter Revised 09-28-07
' two benefits: it reduces thermal heating of the water, and it helps to maintain a healthy
and aesthetic pond by reducing algal blooms and the potential for anaerobic conditions.
Full size trees and very large woody shrubs should not be planted on embankments
' since under some circumstances their presence can threaten the structural integrity of
the embankment. All trees and shrubs should be set back so that the branches will not
extend over the basin.
' Wildflowers, native grasses, and ground covers should be selected to minimize mowing;
fertilizing will be allowed for initial establishment.
' 10.3.8. Surrounding Soils and Liners
When a wet detention basin is to be located in gravelly sands or fractured bedrock, the
t designer may incorporate a liner to sustain a permanent pool of water. When wet
detention basins are near wetlands or other waters, additional engineering calculations
and engineering measures may be necessary to insure that these waters will not be
' adversely affected by the location of the wet detention basin nor will the wet detention
basin be drained into the adjacent waters. The installation of additional engineering
features, such as slurry walls, liners, or other barriers may be required.
10.3.9. Outlet Design
' The outlet device shall be designed to release the temporary pool volume over a period
of 48 to 120 hours (2 to 5 days). Longer detention times typically do not improve settling
efficiency significantly, and the temporary pool volume must be available for the next,
' storm. In addition, prolonged periods of inundation can adversely affect the wetland
vegetation growing on the vegetated shelf.

In addition to being designed to achieve the 2 to 5-day drawdown period, outlets also
must be functionally simple and easy to maintain. One configuration of the outlet
piping that simplifies maintenance and reduces the potential for obstruction is the
submerged orifice arrangement shown in Figure 10-4.
I
Wet Detention Basin
10-12
Tiny 2007

' NCDENR Stormwater BW Manual Chapter Revised 09-28-07

' Figure 10-4
Typical Submerged Orifice Outlet Configuration
1
4" PVC
t Screvr= . In g tee
?P g
0,1104t 40, X
Tea?'M!?q POW

Femual eiif

f 1?

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ftgDurable materials, such as reinforced concrete, are preferable to corrugated metal in

most instances. The riser should be placed in or at the face of the embankment. By
placing the riser close to the embankment, maintenance access is facilitated and flotation
forces are reduced. The design engineer must present flotation force calculations for any
outlet design subject to flotation forces. Outlets are described in greater detail in Section
5.0, Common BW Design Elements.
Emergency overflow spillways must be designed with hardened materials at the points
where extreme conditions might compromise the integrity of the structure.
Under most circumstances North Carolina rules require a vegetative filter strip on the
discharge from a wet detention basin, along with a level spreader or other engineered
device to ensure even, non-erosive distribution of the flow. Wet detention ponds
designed for 85 % TSS removal are required to discharge through a 30 foot vegetated
filter to minimize erosion and to provide additional pollutant removal. There may be
projects where it is difficult to construct a functional vegetated filter, and the outflow
must discharge to the watercourse. In these instances, additional storage should be
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' NCDENR Stormwater BMP Manual Chapter Revised 09-28-07
' provided to compensate for the lack of a filter and the pond must be designed to remove
90% TSS instead of 85%. Chapter 13 Filter Strip contains information on the design
elements of the vegetative filter strip. Chapter 8 Level Spreader contains information on
' the design elements of a level spreader.
10.3.10. Fountains in the Wet Pond
t Fountains are optional, decorative wet pond amenities. If they are included they shall
be designed as follows:
' 1. The fountain must draw its water from less than 2' below the permanent pool
surface.
2. Separated units (where the nozzle, pump and intake are connected by tubing)
t may be used only if they draw water from the surface in the deepest part of the
pond.
3. The falling water from the fountain must be centered in the pond, away from the
' shoreline.
4. The maximum horsepower for the fountain's pump is based on the permanent
pool volume, as described in Table 10-5. As an example, if the pond's volume is
' 350,000 cubic feet, the maximum pump horsepower for the fountain is 1. For
ponds with less than 30,000 cubic feet, use 1/$ HP.

Table 10-5
Fountain Pump Power fZequirements

Minimum Pond Max
Volume Pump
W) HP
30,000 1/8
40,000 1/6
60,000 1/4
80,000 1/3

125,000 -
1/2
175,000 3/4
250,000 1
450,00 2
675;000 3
' 10.3.11. Safety Considerations
The permanent pool of water presents an attractive play area to children and thus may
' create safety problems. Engineering design features that discourage child access are
recommended. Trash racks and other debris-control structures should be sized to
prevent entry by children. Other safety considerations.include using fences around the
' spillway structure, embankment, and wet detention basin slopes; using shallow safety
benches around the wet.detention basin; and posting warning signs.
Fencing of wet detention basins is not generally aesthetically pleasing but may be
' required by the local review authority. A preferred method is to engineer the contours of
the wet detention basin to eliminate drop offs and other safety hazards as discussed
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NCDENR Stormwater BMP Manual Chapter Revised 09-28-07
above. Riser openings must not permit unauthorized access. End walls above pipe
outfalls greater than 48 inches in diameter should be fenced to prevent falls.
10.4 Construction
Even moderate rainfall events during the construction of a wet detention basin can cause
extensive damage to it. Protective measures should be employed both in the
contributing drainage area, and at the wet detention basin itself. Temporary drainage or
erosion control measures should be used to reduce the potential for damage to the wet
detention basin before the site is stabilized. The control measures may include
stabilizing the surface with erosion mats, sediment traps, and diversions. Vegetative
cover and the emergency spillway also should be completed as quickly as possible
during construction.
The designer should address the potential for bedding erosion and catastrophic failure
of any buried outlet conduit. A filter diaphragm and drain system should be provided
along the barrel of the principal spillway to prevent piping. DWQ is aware of an
evolution in standard practice, and of accumulated evidence suggesting that in most
circumstances filter diaphragms are much superior to anti seep collars in preventing
piping. DWQ strongly prefers filter diaphragms to the older design anti seep collar.
If reinforced concrete pipe is used for the principal spillway, "O-ring" gaskets (ASTM
C361) should be used to create watertight joints and should be inspected during
' installation.
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10.5. Maintenance
10.5.1 Common Maintenance Issues
Please refer to Section 7.0, General BMP Maintenance, for information on types of
maintenance, typical frequency, and specific maintenance tasks that are common to all
B.MPs. The following information is maintenance that is specific to wet detention basins.
Specific items that require careful inspection for a wet detention basin include:
evaluation of the aquatic environment, vegetation, and sediment build-up.
A program of monitoring the aquatic environment of a permanent wet detention basin
should be established. Items such as water clarity and algal growth should be monitored
regularly.
The vegetation located on the vegetated shelf must be properly maintained in order to
achieve additional pollutant removal and in order to prevent bank erosion. Bare spots,
weeds, and invasive species should be noted and remedied as soon as possible to
prevent larger problems. Although a regular grass maintenance program for the upland
locations around the BMP will reduce weed intrusion, some weeds invariably will
appear. Periodic weeding will therefore be necessary. Chemical application to control
weeds should be carefully considered and monitored. Frequent maintenance activities
such as removing debris and cutting grass will result in a facility that is both functional
and attractive.
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' Sediment accumulation should be monitored through visual inspection of the basin
bottoms and the sediment accumulation depth marker. When the specified depth of
sediment has been reached in either the forebay or main basin, the sediment should be
removed and disposed of properly, and the forebay or main basin repaired as designed
(e.g. proper vegetation replaced).
' 10.5.2. Sample Inspection and Maintenance Provisions
Important maintenance procedures:
t - Immediately after the wet detention basin is established, the plants on the
vegetated shelf and perimeter of the basin should be watered twice weekly if
needed, until the plants become established (commonly six weeks).
' - No portion of the wet detention pond should be fertilized after the first initial
fertilization that is required to establish the plants on the vegetated shelf.
- Stable groundcover should be maintained in the drainage area to reduce the
' sediment load to the wet detention basin.
- If the basin must be drained for an emergency or to perform maintenance, the
flushing of sediment through the emergency drain should be minimized to the
maximum extent practical.
- Once a year, a dam safety expert should inspect the embankment.
' After the wet detention pond is established, it should be inspected once a month and
within 24 hours after every storm event greater than 1.0 inches (or 1.5 inches if in a
Coastal County). Records of inspection and maintenance should be kept in a known set
' location and must be available upon request.
Inspection activities shall be performed as follows. Any problems that are found shall
' be repaired immediately.
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NCDENR Stormwater BMP Manual Chapter Revised 09-28-07
Table 10-6
Sample Inspection and Maintenance Provisions for Wet Detention Basins
BMP element: Potential problems: How to remediate the problem:
The entire BMP Trash debris is resent. Remove the trash debris.
The perimeter of the wet Areas of bare soil and/or Regrade the soil if necessary to
detention basin erosive gullies have formed. remove the gully, and then plant a
ground cover and water until it is
established. Provide lime and a
one-time fertilizer application.
Vegetation is too short or too Maintain vegetation at a height of
long. approximately six inches.
The inlet device: pipe or The pipe is clogged. Unclog the pipe. Dispose of the
swale sediment off-site.
The pipe is cracked or Replace the pipe.
otherwise damatred.
Erosion is occurring in the Regrade the swale if necessary to
swale. smooth it over and provide erosion
control devices such as reinforced
turf matting or riprap to avoid
future vroblems with erosion.
The fvrebay Sediment has accumulated to
a depth greater than the
original design depth for
sediment storage.
Erosion has occurred.
Weeds are present.
Search for the source of the
sediment and remedy the problem if
possible. Remove the sediment and
dispose of it in a location where it
will not cause impacts to streams or
the BMP.
Provide additional erosion
protection such as reinforced turf
matting or riprap if needed to
prevent future erosion .problems.
Remove the weeds, preferably by
hand. If pesticide is used, wipe it on
the plants rather than spraying.
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NCDENR Stormwater BMP Manual Chapter Revised 09-28-07
Table 10-6, continued
Sample Inspection and Maintenance Provisions for Wet Detention Basins
BMP element:
The vegetated shelf
The main treatment area
The outlet device
The receiving water
Potential problems:
Best professional practices
show that pruning is needed
to maintain optimal plant
health.
Plants are dead, diseased or
dying.
Weeds are present.
Sediment has accumulated to
a depth greater than the
original design sediment
storage depth.
Algal growth covers over
50% of the area.
Cattails, phragmites or other
invasive plants cover 50% of
the basin surface.
Shrubs have started to grow
on the embankment.
Evidence of muskrat or
beaver activity is present.
A tree has started to grow on
the embankment.
An annual inspection by an
appropriate professional
shows that the embankment
needs repair.
Clogging has occurred.
The outlet device is damaged
Erosion or other signs of
damage have occurred at the
outlet.
How to remediate the problem
Prune according to best professional
practices
Determine the source of the
problem: soils, hydrology, disease,
etc. Remedy the problem and
replace plants. Provide a one-time
fertilizer application to establish the
ground cover if a soil test indicates
it is necessary.
Remove the weeds, preferably by
hand. If pesticide is used, wipe it on
the plants rather than spraying.
Search for the source of the
sediment and remedy the problem if
possible. Remove the sediment and
dispose of it in a location where it
will not cause impacts to streams or
the BMP.
Consult a professional to remove
and control the algal growth.
Remove the plants by wiping them
with pesticide (do not spray).
Remove shrubs immediately.
Use traps to remove muskrats and
consult a professional to remove
beavers.
Consult a dam safety specialist to
remove the tree.
Make all needed repairs.
Clean out the outlet device. Dispose
of the sediment off-site.
Repair or replace the outlet device.
Contact the local NC Division of
Water Quality Regional Office, or
the 401 Oversight Unit at 919-733-
1786.
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NCDENR Stormwater BMP Manual Chapter Revised 09-28-07
Figure 10-5: Example Clean Out Diagram
The measuring device used to determine the sediment elevation shall be such that it will
give an accurate depth reading and not readily penetrate into accumulated sediments.
When the permanent pool depth reads feet in the main pond, the sediment shall
be removed.
When the permanent pool depth reads feet in the forebay, the sediment shall be
removed.
BASIN DIAGRAM
(fill in the blanks)
V Permanent Pool Elevation
Sediment Removal El. Te en Pool
-------------- -- Volume Sediment Removal Elevation Volume
Bottom Elevation -ft Min. --------------------------------------------- ------
Sediment Bottom Elevation 1-ft
Storage Sedimei
Storage
FORLBAY MAIN POND
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NCDENR Stormwater BMP Manual Chapter Revised 09-28-07
September 28 2007 Chanaes•
1. Major Design Elements:
i. Reformatted to include numbered requirements.
ii. Clarified the filter strip requirements for ponds designed to remove 90% TSS. The
requirement now reads, "Basin discharge shall be evenly distributed across a
minimum 30 feet long vegetative filter strip unless it is designed to remove 90% TSS.
(A 50-$ filter is required in some locations.)"
iii. For clarification, the word "full" was removed from, "A minimum 10-foot wide
vegetated shelf shall be installed around the full perimeter."
iv. Added "The pond shall be designed with side slopes no steeper than 3:1." per 15A
NCAC 02H. 1008(e)(8). The vegetated 3:1 requirement was already included per
15A NCAC 02H. 1008(c)(2).
v. Added, "If any portion is used for S&EC during construction must be cleaned out and
returned to design state." per 15A NCAC 02H. 1008(c)(7).
vi. Added, "The design storage shall be above the permanent pool." per 15A NCAC 02H
.1008(e)(1).
vii. Added, "The flow within the pond shall not short-circuit the pond." per 15A NCAC
0211.1008(e)(4).
2. 10.3.2: Added, "Two retaining walls may be used, as shown in Figure 10-3. Or, the
design may be altered to contain only one of the two shown," to clarify the wet pond
design requirements when retaining wall(s) are used
1 10.3.5: Removed a reference to the Simple Method, and specified that the treatment
volume shall be calculated as specified in Section 3.
4. 10.3.6: Added "in addition to the permanent pool volume" to, "DWQ requires that
engineering designs for wet detention basins include at least one additional foot of depth
for sediment storage in addition to the permanent pool volume." This is also shown in
Figure 10-2b and 10-3.
5. 10.3.7: Added a reference to the vegetated shelf planting requirements in Chapter 6 and
the list of appropriate wetland plantings for the vegetated shelf in Chapter 9.
6. 10.3.9: Clarified the filter strip requirements for ponds designed to remove 90% TSS.
7. 10.3.10: Added guidance for decorative fountains.
8. 10.5.2: Deleted references to "aquatic shelf'. Replaced with "vegetated shelf".
9. Figure 10-2a: Renumbered (previously Figure 10-2). Altered previous diagram for
clarification. (Plan view wet pond requirements.)
10. Figure 10-2b: Added a figure showing a cross-section of wet pond requirements.
11. Figure 10-3: Added a figure showing the retaining wall option.
12. Figure 10-4: Renumbered. Previously Figure 10-3.
13. Figure 10-5: Added and example clean out diagram for clarification.
14. Table 10-3: Added 90% TSS SA/DA table for the piedmont region.
15. Table 10-4: Renumbered. Previously Table 10-3.
16. Table 10-5: Added decorative fountain pump horsepower requirements.
17. Table 10-6: Renumbered. Previously Table 10-4.
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