Exhibit 9-1
Off-Street Parking Requirements for Residential
Land Uses
| |||
---|---|---|---|
Housing Unit
(type/size)
|
Off-Street Parking Requirement
(number of spaces)
| ||
Single-family detached
| |||
1 bedroom
|
1.5
| ||
2 bedrooms
|
2.0
| ||
3 bedrooms
|
2.0
| ||
4 bedrooms (or more)
|
3.0
| ||
Garden apartment
| |||
1 bedroom
|
1.8
| ||
2 bedrooms
|
2.0
| ||
3 bedrooms
|
2.1
| ||
Townhouse
| |||
1 bedroom
|
1.8
| ||
2 bedrooms
|
2.3
| ||
3 bedrooms
|
2.4
| ||
Mid-rise
| |||
Studio
|
0.8
| ||
1 bedroom
|
1.3
| ||
2 bedrooms
|
1.9
| ||
Senior citizen housing
| |||
For each unit
|
0.5
| ||
For each 2 units
|
1.0
|
Exhibit 9-2
Off-Street Parking Requirements1 for Nonresidential
Land Uses
| |||
---|---|---|---|
Nonresidential Land Uses
|
Required Off-Street Parking Spaces Per
Indicated Area
| ||
Banks and savings and loan associations
|
1 per 200 square feet GFA plus room for 12 cars
per drive-up window and/or lane
| ||
Bar, tavern, or similar
|
1 per 2 seats or 1 per 100 square feet GFA (whichever
is greater)
| ||
Community club, private club lodge
|
1 per 100 square feet GFA
| ||
Commercial recreation:
| |||
Indoor
|
1 per 50 square feet GFA
| ||
Outdoor
|
1 per 4 spectators, based on maximum capacity,
and 3 per 10,000 square feet outdoor play area
| ||
Dental or medical office
|
1 per 100 square feet GFA.
| ||
Industrial, light manufacturing and wholesaling
|
1 per employee per shift
| ||
Library
|
1 per 300 square feet GFA
| ||
Marina, boat yard, boat sales; meeting rooms,
assembly or public auditorium; motel, hotel, rooming house; motor
vehicle service station; offices2
|
1 per boat slip; 1 per 50 square feet of GFA
or 1 per 4 seats, whichever is greater; 1 per room plus 0.5 per employee;
4 per bay or work area
| ||
Business1(4):
| |||
Under 10,000 GFA
|
4.5 per 1,000 square feet GFA
| ||
Other
|
4.0 per 1,000 square feet GFA
| ||
Outdoor sales area
|
1 per 2,000 square feet lot area used for storage
| ||
Places of worship
|
1 per 3 seats
| ||
Restaurant
|
1 per 3 seats or 1 per 50 square feet GFA, whichever
is greater
| ||
Retail store or personal service establishment
|
1 per 200 square feet GFA
| ||
Schools:
| |||
Elementary
|
1 per teacher and staff
| ||
Intermediate
|
1 per teacher and staff
| ||
Secondary
|
1 per 3 students
| ||
Shopping center3
|
1 per 250 square feet GFA
| ||
Studio, art, music, dance, for purpose of giving
instruction
|
1 per 100 square feet GFA
| ||
Theater
|
1 per 3 seats
| ||
In shopping center
|
1 per 4 seats
| ||
Warehouse
|
1 per 5,000 square feet GFA
|
NOTES:
| |||
1
|
In computing the number of required parking
spaces, the following shall apply:
| ||
(1)
|
Where fractional spaces result, the required
number shall be construed to be the next highest whole number.
| ||
(2)
|
The parking space requirements for a use not
specifically mentioned herein shall be the same as required for a
use of similar nature as determined by the Planning Board.
| ||
(3)
|
If there is no use enumerated herein having
sufficient similarity to the use proposed to enable the Planning Board
to establish rational parking requirements, the Planning Board may,
in its discretion, direct the applicant to furnish the Planning Board
with such data as may be necessary to enable the Planning Board to
establish rational parking requirements.
| ||
(4)
|
Where there is a mixed use, the number of spaces
shall equal the sum of those spaces required for each use when calculated
separately.
| ||
2
|
A building of mixed office uses may include
a maximum of 1/3 medical or dental floor area. If medical or dental
uses exceed 1/3 of the gross floor area, their parking requirement
shall be computed separately.
| ||
3
|
If more than 25% of the total floor area is
occupied by a nonretail use which has off-street parking requirements
greater than those required for a shopping center, then off-street
parking for the center shall be the same as the required minimum for
the nonretail use plus the required minimum for the balance of the
shopping center floor area.
|
Double Minimum Parking Bay Width
(feet)
| ||||
---|---|---|---|---|
Parking Angle
(degrees)
|
Normal
|
Long Term
|
Minimum Aisle Width
(feet)
| |
30
|
48
|
46
|
12
| |
45
|
50
|
48
|
13
| |
60
|
55
|
53
|
18
| |
90
|
62
|
60
|
24
|
Accessible Parking Spaces
| ||
---|---|---|
Total Parking In Lot
|
Required Number of Accessible Spaces
| |
Up to 50
|
1
| |
51 to 200
|
2
| |
Over 200
|
2 plus 1% of the number of spaces over 200 rounded to the next
higher whole number
| |
Parking facility serving long-term care facility
|
2% of the spaces but not less than 2
|
Square Feet of Total Floor Area
|
Number of Spaces
| |
---|---|---|
5,000 to 10,000
|
1
| |
10,000 to 25,000
|
2
| |
25,000 to 40,000
|
3
| |
40,000 to 60,000
|
4
| |
For each additional 50,000
|
1 additional space or fraction thereof
|
Exhibit 9-4
Fire Flows
| |||
---|---|---|---|
Population
|
Flow GPM*
|
Duration of Flow
(hours)
| |
Under 100
|
500
|
4
| |
1,000
|
1,000
|
4
| |
1,500
|
1,250
|
5
| |
2,000
|
1,500
|
6
| |
3,000
|
1,750
|
7
| |
4,000
|
2,000
|
8
| |
5,000
|
2,250
|
9
| |
6,000
|
2,500
|
10
| |
10,000
|
3,000
|
10
|
NOTE:
| ||
---|---|---|
*
|
GPM = gallons per minute.
|
Exhibit 9-5
Design Standards for Peak-Hour Flow
| ||
---|---|---|
Total Houses Served
|
Peak Hourly Rates
(GPM per house)
| |
5
|
8.0
| |
10
|
5.0
| |
50
|
3.0
| |
100
|
2.0
| |
250
|
1.3
| |
500
|
0.8
| |
750
|
0.7
| |
1,000 or more
|
0.6
|
Exhibit 9-6
Short Method for Calculating Fire Flows
| ||
---|---|---|
Distance Between Buildings*
(feet)
|
Required Fire Flow
(gallons per minute)
| |
Over 100
|
500
| |
31 to 100
|
750 to 1,000
| |
11 to 30
|
1,000 to 1,500
| |
10 or less
|
1,500 to 2,000
|
NOTE:
| ||
---|---|---|
*
|
For contiguous buildings (attached dwelling
units of two or more, two-family units and/or multifamily units),
a minimum of 2,500 GPM may be used.
|
Exhibit 9-7
Average Daily Residential Sewer Flow
| ||||
---|---|---|---|---|
Type of Establishment
|
Measurement Unit
|
Gallons Per Day
| ||
Single-family dwelling
|
Unit
|
300
| ||
Apartment/condominium/ townhouse
|
1 bedroom
|
150
| ||
2 bedroom
|
225
| |||
3 bedroom
|
300
| |||
Transit Dwelling Units
| ||||
Hotels
|
Bedroom
|
75
| ||
Lodging houses
|
Bedroom
|
60
| ||
Motels
|
Bedroom
|
60
| ||
Boardinghouses
|
Boarder
|
50
| ||
Camps
| ||||
Taller camps (private bath)
|
Person
|
75
| ||
Trainer camp (central bath)
|
Person
|
50
| ||
Luxury camps (private bath)
|
Person
|
75
| ||
Childrens' camps (central bath)
|
Person
|
50
| ||
Labor camps
|
Person
|
40
| ||
Day camps - no meals
|
Person
|
15
| ||
Restaurants
| ||||
Average type
|
Patron
|
15
| ||
Bar and cocktail lounges
|
Patron
|
5
| ||
Short-order or drive-in service
|
Patron
|
5
| ||
Clubhouses
| ||||
Residential type
|
Person
|
75
| ||
Nonresidential (serving meals)
|
Person
|
35
| ||
Institutions
| ||||
Hospitals
|
Person
|
200
| ||
Other
|
Person
|
125
| ||
Schools
| ||||
Elementary (no shower or cafeteria)
|
Person
|
10
| ||
With cafeteria
|
Person
|
15
| ||
With cafeteria and showers
|
Person
|
20
| ||
With cafeteria, showers and laboratories
|
Person
|
25
| ||
Boarding
|
Person
|
75
| ||
Automobile Service Stations
| ||||
No car washing
|
Car served
|
5
| ||
Car washing
|
Car washed
|
75
| ||
Miscellaneous
| ||||
Retail and office buildings
|
Square feet
|
0.125
| ||
Factories (8-hour shift)
|
Person
|
25
| ||
Warehouse
|
Person
|
25
| ||
Self-service laundries
|
Wash
|
50
| ||
Bowling alleys
|
Alley
|
200
| ||
Swimming pool and beaches
|
Person
|
15
| ||
Picnic parks (with flush toilets)
|
Person
|
10
| ||
Fairgrounds (based upon average attendance)
|
Person
|
5
| ||
Assembly halls
|
Seat
|
5
| ||
Airports (based on passenger use)
|
Passenger
|
3
| ||
Churches
|
Seat
|
5
| ||
Theater (indoor)
|
Seat/car
|
5
|
Type of Concrete
|
Average Strength
(pounds per square inch)
| |
---|---|---|
Class P
|
6,500
| |
Class A
|
5,500
| |
Class B, B-1
|
5,000
| |
Class C, C-1
|
4,500
|
Exhibit 9-8
Intersection Standards
| |||
---|---|---|---|
Intersection Standards
|
Local Street
|
Collector Street
| |
Maximum grade within 50 feet of intersection
|
5%
|
3%
| |
Minimum center-line radius
|
150 feet
|
300 feet
| |
Minimum tangent length between reverse curves
|
100 feet
|
150 feet
| |
Curb radii
|
25 feet
|
35 feet
|
Exhibit 9-10
Pavement Specifications
| |||
---|---|---|---|
Local Streets
| |||
Bituminous concrete surface course, Mix I-5
|
1 1/2" thick
| ||
Bituminous stabilized base course, Mix I-2
|
3 1/2" thick
| ||
Prime coat on gravel base
| |||
Gravel base course, soil aggregate, gradation
designation I-5
|
6" thick1,2,3
| ||
If required add:4 subbase, soil aggregate, gradation designation I-2 or I-3
|
6" thick
| ||
Collector Streets
| |||
Bituminous concrete surface course, Mix I-5
|
1 1/2" thick
| ||
Bituminous stabilized base course, Mix I-2 (laid
in two courses)
|
4 1/2" thick
| ||
Prime coat on gravel base
| |||
Gravel base course, soil aggregate, gradation
designation I-5
|
8" thick1,2,3
| ||
If required add:4 subbase, soil aggregate, gradation designation I-2 or I-3
|
8" thick
| ||
Parking Areas and Aisles5
| |||
Bituminous concrete surface course, Mix I-5
|
1 1/2" thick
| ||
Bituminous stabilized base course, Mix I-2
|
2" thick
| ||
Gravel base course, soil aggregate, gradation
designation I-5
|
4 1/2" thick1,2
|
NOTES:
| ||
---|---|---|
1
|
Bituminous stabilized base course may be substituted
for gravel base course on a one-inch-to-three-inch ratio.
| |
2
|
If subgrade is approved as adequate by the Engineer,
gravel base course may be completely eliminated and bituminous stabilized
base course may be substituted on one-inch-to-three-inch ratio.
| |
3
|
Gravel base course may be reduced to three inches
minimum if subbase is provided.
| |
4
|
Subbase may be required depending on subgrade
soils, groundwater elevations and other variables.
| |
5
|
Portions of parking areas and aisles likely
to be subjected to significant heavy truck traffic shall meet the
standards for local streets.
|
Exhibit 9-11
Illumination Guidelines
| |
---|---|
A.
|
Street illumination.
|
Area Classification
| ||||||
---|---|---|---|---|---|---|
Commercial
|
Intermediate
|
Residential
| ||||
Street Hierarchy
|
Lux
|
Footcandles
|
Lux
|
Footcandles
|
Lux
|
Footcandles
|
Collector
|
13
|
1.2
|
10
|
0.9
|
6
|
0.6
|
Local
|
6
|
0.6
|
4
|
0.4
|
4
|
0.4
|
B.
|
Parking illumination (open parking facilities).
|
Illumination Objective
| ||||||
---|---|---|---|---|---|---|
Vehicular Traffic
|
Pedestrian Safety
|
Pedestrian Security
| ||||
Level of Activity
|
Lux
|
Footcandles
|
Lux
|
Footcandles
|
Lux
|
Footcandles
|
Low activity
|
5
|
0.5
|
2
|
0.2
|
9
|
0.8
|
Medium activity
|
11
|
1
|
6
|
0.6
|
22
|
2
|
High activity
|
22
|
2
|
10
|
0.9
|
43
|
4
|
C.
|
Pedestrianway illumination.
|
Minimum Average Level
|
Average Levels for Special Pedestrian
Security
| ||||||
---|---|---|---|---|---|---|---|
Mounting Heights 3 to 5 meters
(9 to 15 feet)
|
Mounting Heights 5 to 10 meters
(15 to 30 feet)
| ||||||
Walkways and Bikeway Classification
|
Lux
|
Footcandles
|
Lux
|
Footcandles
|
Lux
|
Footcandles
| |
Sidewalks (roadside) and Type A bikeways
| |||||||
Commercial areas
|
10
|
0.9
|
22
|
2.0
|
43
|
4.0
| |
Intermediate areas
|
6
|
0.6
|
11
|
1.0
|
22
|
2.0
| |
Residential areas
|
2
|
0.2
|
4
|
0.4
|
9
|
0.8
| |
Walkways distant from roadways and
Type B bikeways
| |||||||
Park walkways and bikeways
|
5
|
0.5
|
6
|
0.6
|
11
|
1.0
| |
Pedestrian tunnels
|
43
|
4.0
|
54
|
5.0
|
—
|
—
| |
Pedestrian overpasses
|
3
|
0.3
|
4
|
0.4
|
—
|
—
| |
Pedestrian stairways
|
6
|
0.6
|
9
|
0.8
|
—
|
—
|
IES Lighting Handbook definitions:
| |||
1.
|
Area classification:
| ||
1.
|
Commercial. That portion of a municipality in
a business development where ordinarily there are large numbers of
pedestrians during business hours.
| ||
2.
|
Intermediate. That portion of a municipality
often characterized by a moderately heavy nighttime pedestrian activity
such as in blocks having libraries, community recreation centers,
large apartment buildings or neighborhood retail stores.
| ||
3.
|
Residential. A residential development, or a
mixture of residential and commercial establishments, characterized
by a few pedestrians at night. This definition includes areas with
single-family homes, townhouses and/or small apartment buildings.
| ||
2.
|
Activity level:
| ||
High activity. Major-league athletic events,
cultural or civic events, and major regional shopping centers.
| |||
Medium activity. Fast-food facilities, area
shopping centers, hospital parking areas, transportation parking (airports,
etc.), cultural, civic or recreational events, and residential complex
parking.
| |||
Low activity. Local merchant parking, industrial
employee parking, educational facility parking.
| |||
3.
|
Bikeway classification:
| ||
1.
|
Type A bikeway — a strip within or adjacent
to a public roadway or shoulder, used for bicycle travel.
| ||
2.
|
Type B bikeway — an improved strip identified
for public bicycle travel and located away from a roadway or its adjacent
sidewalk system.
|
Exhibit 9-12
Color Code System for Fire Hydrants
| ||
---|---|---|
Class A
|
1,000 gpm or greater and water mains of 10 inches
and greater: green caps and bonnets
| |
Class B
|
500 gpm or greater but less than 1,000 gpm and
water mains of at least eight inches but less than 10 inches: orange
caps and bonnets
| |
Class C
|
500 gpm or less and water mains of at least
six inches but less than eight inches: red caps and bonnets
| |
Barrels
|
All fire hydrants shall be chrome yellow or
equivalent, and all yellow paint shall be of "traffic yellow."
|
Exhibit 9-13
Minimum Slopes for Sewer Size by Pipe
Diameter
| ||
---|---|---|
Pipe Diameter
(inches)
|
Fall
(in feet per 100 feet of sewer)
| |
8
|
0.40
| |
10
|
0.29
| |
12
|
0.22
| |
14
|
0.17
| |
15
|
0.16
| |
16
|
0.14
| |
18
|
0.12
| |
20
|
0.10
| |
21
|
0.095
| |
24
|
0.080
| |
27
|
0.067
| |
30
|
0.058
| |
36
|
0.046
|
Exhibit 9-14
Maximum Trench Depth
Pipe Class Requirements for Reinforced
Concrete Pipe
| |||
---|---|---|---|
Pipe Diamete
(inches)
|
Maximum Widths of Trench at Top
of Pipe
|
Depth-Feet
(pipe class)
| |
IV
|
V
| ||
12 and smaller
|
3'-0"
|
6.5
|
18.0
|
15
|
3'-8"
|
6.0
|
14.0
|
18
|
4'-0"
|
7.0
|
16:0
|
21
|
4'-3"
|
8.5
|
17.5
|
24
|
4'-6"
|
9.0
|
20.0
|
30
|
5'-0"
|
10.5
|
22.5
|
36
|
5'-8"
|
11.0
|
22.0
|
4" cast iron soil pipe, extra heavy
| |
4" PVC plastic pipe, Schedule 40 4"
| |
ABS plastic pipe, SDR 35
|
Qp = CIA
| ||||
---|---|---|---|---|
Where
| ||||
Qp
|
=
|
The peak runoff rate in cubic feet per second
(CFS).
| ||
C
|
=
|
The runoff coefficient.
| ||
I
|
=
|
The average rainfall intensity in inches per
hour (inch/hour), occurring at the time of concentration t, (minutes)
tc = the time of concentration in minutes (minimum).
| ||
A
|
=
|
The size of the drainage area.
|
Exhibit 9-15
Runoff Coefficients
AMC II
| ||||||
---|---|---|---|---|---|---|
Hydro. Soil Group
| ||||||
Land Use Description
|
A
|
B
|
C
|
D
| ||
Cultivated land:
| ||||||
Without conservation treatment
|
0.49
|
0.67
|
0.81
|
0.88
| ||
With conservation treatment
|
0.27
|
0.43
|
0.67
|
0.67
| ||
Pasture or range land:
| ||||||
Poor condition
|
0.38
|
0.63
|
0.78
|
0.84
| ||
Good condition
|
—
|
0.25
|
0.51
|
0.65
| ||
Meadow: good condition
|
—
|
—
|
0.41
|
0.61
| ||
Wood or Forest land:
| ||||||
Thin stand, poor cover, no mulch
|
—
|
0.34
|
0.59
|
0.70
| ||
Good cover
|
—
|
—
|
0.45
|
0.59
| ||
Open spaces, lawns, parks, golf courses, cemeteries:
| ||||||
Good conditions: grass cover on 75% or more
of the area
|
—
|
0.25
|
0.51
|
0.65
| ||
Fair condition: grass cover on 50% to 75% of
the area
|
—
|
0.45
|
0.63
|
0.74
| ||
Commercial and business areas (85% impervious)
|
0.84
|
0.90
|
0.93
|
0.96
| ||
Industrial districts (72% impervious)
|
0.67
|
0.81
|
0.88
|
0.92
| ||
Residential:
| ||||||
Average lot size
|
Average % Impervious
| |||||
1/8 acre or less
|
65
|
0.59
|
0.76
|
0.86
|
0.90
| |
1/4 acre
|
38
|
0.29
|
0.55
|
0.70
|
0.80
| |
1/3 acre
|
30
|
—
|
0.49
|
0.67
|
0.78
| |
1/2 acre
|
25
|
—
|
0.45
|
0.65
|
0.76
| |
1 acre
|
20
|
—
|
0.41
|
0.63
|
0.74
| |
Paved parking lots, roofs, driveways, etc.
|
0.99
|
0.99
|
0.99
|
0.99
| ||
Streets and roads:
| ||||||
Paved with curbs and storm sewers
|
0.99
|
0.99
|
0.99
|
0.99
| ||
Gravel
|
0.57
|
0.76
|
0.84
|
0.88
| ||
Dirt
|
0.49
|
0.69
|
0.80
|
0.84
|
NOTE: Values are based on SCS definitions
and are average values derived by an Advisory Committee for this Manual.
|
Q = 1.486\n AR213 S1/2
| ||||
---|---|---|---|---|
Where
| ||||
n
|
=
|
Manning's roughness coefficient.
| ||
A
|
=
|
Cross-sectional area of flow in square feet.
| ||
R
|
=
|
Hydraulic radius in feet (R = A/P, where P is
equal to the wetted perimeter).
| ||
S
|
=
|
Slope of conduit in feet per foot.
| ||
The Manning roughness coefficients to be utilized
are shown in Exhibit 9-18.
|
Exhibit 9-18
Manning's Roughness Coefficients
Values of the Roughness Coefficient "n"
| |||||||
---|---|---|---|---|---|---|---|
Type of Channel
|
Minimum
|
Normal
|
Maximum
| ||||
A.
|
CLOSED CONDUITS FLOWING PARTLY FULL
| ||||||
A-1.
|
Metal
| ||||||
a.
|
Brass, smooth
|
0.009
|
0.010
|
0.013
| |||
b.
|
Steel
| ||||||
1.
|
Lockbar and welded
|
0.010
|
0.012
|
0.014
| |||
2.
|
Riveted and spiral
|
0.013
|
0.016
|
0.017
| |||
c.
|
Cast iron
| ||||||
1.
|
Coated
|
0.010
|
0.013
|
0.014
| |||
2.
|
Uncoated
|
0.011
|
0.014
|
0.016
| |||
d.
|
Wrought iron
| ||||||
1.
|
Black
|
0.012
|
0.014
|
0.015
| |||
2.
|
Galvanized
|
0.013
|
0.016
|
0.017
| |||
e.
|
Corrugated metal
| ||||||
1.
|
Subdrain
|
0.017
|
0.019
|
0.021
| |||
2.
|
Storm drain
|
0.021
|
0.024
|
0.030
| |||
A-2.
|
Nonmetal
| ||||||
a.
|
Lucite
|
0.008
|
0.009
|
0.010
| |||
b.
|
Glass
|
0.009
|
0.010
|
0.013
| |||
c.
|
Cement
| ||||||
1.
|
Neat, surface
|
0.010
|
0.011
|
0.013
| |||
2.
|
Mortar
|
0.011
|
0.013
|
0.015
| |||
d.
|
Concrete
| ||||||
1.
|
Culvert, straight and free of debris
|
0.010
|
0.011
|
0.013
| |||
2.
|
Culvert with bends, connections, and some debris
|
0.011
|
0.013
|
0.014
| |||
3.
|
Finished
|
0.011
|
0.012
|
0.014
| |||
4.
|
Sewer with manholes, inlet, etc., straight
|
0.013
|
0.015
|
0.017
| |||
5.
|
Unfinished, steel form
|
0.012
|
0.013
|
0.014
| |||
6.
|
Unfinished, smooth wood form
|
0.012
|
0.014
|
0.016
| |||
7.
|
Unfinished, rough wood form
|
0.015
|
0.017
|
0.020
| |||
e.
|
Wood
| ||||||
1.
|
Stave
|
0.010
|
0.012
|
0.014
| |||
2.
|
Laminated, treated
|
0.015
|
0.017
|
0.020
| |||
f.
|
Clay
| ||||||
1.
|
Common drainage tile
|
0.011
|
0.013
|
0.017
| |||
2.
|
Vitrified sewer
|
0.011
|
0.014
|
0.017
| |||
3.
|
Vitrified sewer with manholes, inlet, etc.
|
0.013
|
0.015
|
0.017
| |||
4.
|
Vitrified subdrain with open joint
|
0.014
|
0.016
|
0.018
| |||
g.
|
Brickwork
| ||||||
1.
|
Glazed
|
0.011
|
0.013
|
0.015
| |||
2.
|
Lined with cement mortar
|
0.012
|
0.015
|
0.017
| |||
h.
|
Sanitary sewers coated with sewage slimes, with
bends and connections
|
0.012
|
0.013
|
0.016
| |||
i.
|
Paved invert, sewer, smooth bottom
|
0.016
|
0.019
|
0.020
| |||
j.
|
Rubble masonry, cemented
|
0.018
|
0.025
|
0.030
| |||
B.
|
LINED OR BUILT-UP CHANNELS
| ||||||
B-1.
|
Metal
| ||||||
a.
|
Smooth steel surface
| ||||||
1.
|
Unpainted
|
0.011
|
0.012
|
0.014
| |||
2.
|
Painted
|
0.012
|
0.013
|
0.017
| |||
b.
|
Corrugated
|
0.021
|
0.025
|
0.030
| |||
B-2
|
Nonmetal
| ||||||
a.
|
Cement
| ||||||
1.
|
Neat, surface
|
0.010
|
0.011
|
0.013
| |||
2.
|
Mortar
|
0.011
|
0.013
|
0.015
| |||
b.
|
Wood
| ||||||
1.
|
Planed, untreated
|
0.010
|
0.012
|
0.014
| |||
2.
|
Planed, creosoted
|
0.011
|
0.012
|
0.015
| |||
3.
|
Unplanned
|
0.011
|
0.013
|
0.015
| |||
4.
|
Plank with battens
|
0.012
|
0.015
|
0.018
| |||
5.
|
Lined with roofing paper
|
0.010
|
0.014
|
0.017
| |||
c.
|
Concrete
| ||||||
1.
|
Trowel finish
|
0.011
|
0.013
|
0.015
| |||
2.
|
Float finish
|
0.013
|
0.015
|
0.016
| |||
3.
|
Finished, with gravel on bottom
|
0.015
|
0.017
|
0.020
| |||
4.
|
Unfinished
|
0.014
|
0.017
|
0.020
| |||
5.
|
Gunite, good section
|
0.016
|
0.019
|
0.023
| |||
6.
|
Gunite, wavy section
|
0.018
|
0.022
|
0.025
| |||
7.
|
On good excavated rock
|
0.017
|
0.020
| ||||
8.
|
On irregular excavated rock
|
0.022
|
0.027
| ||||
d.
|
Concrete bottom float finished with sides of
| ||||||
1.
|
Dressed stone in mortar
|
0.015
|
0.017
|
0.020
| |||
2.
|
Random stone in mortar
|
0.017
|
0.020
|
0.024
| |||
3.
|
Cement rubble masonry, plastered
|
0.016
|
0.020
|
0.024
| |||
4.
|
Cement rubble masonry
|
0.020
|
0.025
|
0.030
| |||
5.
|
Dry rubble or riprap
|
0.020
|
0.030
|
0.035
| |||
e.
|
Gravel bottom with sides of
| ||||||
1.
|
Formed concrete
|
0.017
|
0.020
|
0.025
| |||
2.
|
Random stone in mortar
|
0.020
|
0.023
|
0.026
| |||
3.
|
Dry rubble or riprap
|
0.023
|
0.033
|
0.036
| |||
f.
|
Brick
| ||||||
1.
|
Glazed
|
0.011
|
0.013
|
0.015
| |||
2.
|
In cement mortar
|
0.012
|
0.015
|
0.018
| |||
g.
|
Masonry
| ||||||
1.
|
Cemented rubble
|
0.017
|
0.025
|
0.030
| |||
2.
|
Dry rubble
|
0.023
|
0.032
|
0.035
| |||
h.
|
Dressed ashlar
|
0.013
|
0.015
|
0.017
| |||
i.
|
Asphalt
| ||||||
1.
|
Smooth
|
0.013
|
0.013
| ||||
2.
|
Rough
|
0.016
|
0.016
| ||||
j.
|
Vegetal lining
|
0.030
|
—
|
0.500
| |||
C.
|
EXACAVATED OR DREDGED
| ||||||
a.
|
Earth, straight and uniform
| ||||||
1.
|
Clean, recently completed
|
0.016
|
0.018
|
0.020
| |||
2.
|
Clean, after weathering
|
0.018
|
0.022
|
0.025
| |||
3.
|
Gravel, uniform section, clean
|
0.022
|
0.025
|
0.030
| |||
4.
|
With short grass, few weeds
|
0.022
|
0.027
|
0.033
| |||
b.
|
Earth, winding and sluggish
| ||||||
1.
|
No vegetation
|
0.023
|
0.025
|
0.030
| |||
2.
|
Grass, some weeds
|
0.025
|
0.030
|
0.033
| |||
3.
|
Dense weeds or aquatic plants in deep channels
|
0.030
|
0.035
|
0.040
| |||
4.
|
Earth bottom and rubble sides
|
0.028
|
0.030
|
0.035
| |||
5.
|
Stony bottom and weedy banks
|
0.025
|
0.035
|
0.040
| |||
6.
|
Cobble bottom and clean sides
|
0.030
|
0.040
|
0.050
| |||
c.
|
Dragline-excavated or dredged
| ||||||
1.
|
No vegetation
|
0.025
|
0.028
|
0.033
| |||
2.
|
Light brush on banks
|
0.035
|
0.050
|
0.060
| |||
d.
|
Rock cuts
| ||||||
1.
|
Smooth and uniform
|
0.025
|
0.035
|
0.040
| |||
2.
|
Jagged and irregular
|
0.035
|
0.040
|
0.050
| |||
e.
|
Channels not maintained, weeds and brush uncut
| ||||||
1.
|
Dense weeds, high as flow depth
|
0.050
|
0.080
|
0.120
| |||
2.
|
Clean bottom, brush on sides
|
0.040
|
0.050
|
0.080
| |||
3.
|
Same, highest stage of flow
|
0.045
|
0.070
|
0.110
| |||
4.
|
Dense brush, high stage
|
0.080
|
0.100
|
0.140
| |||
D.
|
NATURAL STREAMS
| ||||||
D-1.
|
Minor streams (top width at flood stage 100
ft)
| ||||||
a.
|
Streams on plain
| ||||||
1.
|
Clean, straight, full stage, no rift or deep
pools
|
0.025
|
0.030
|
0.033
| |||
2.
|
Same as above, but more stones and weeds
|
0.030
|
0.035
|
0.040
| |||
3.
|
Clean, winding, some pools and shoals
|
0.033
|
0.040
|
0.045
| |||
4.
|
Same as above, but some weeds and stones
|
0.035
|
0.045
|
0.050
| |||
5.
|
Same as above, lower stages, more ineffective
slopes and sections
|
0.040
|
0.048
|
0.055
| |||
6.
|
Same as 4, but more stones
|
0.045
|
0.050
|
0.060
| |||
7.
|
Sluggish reaches, weedy, deep pools
|
0.050
|
0.070
|
0.080
| |||
8.
|
Very weedy reaches, deep pools, or floodways
with heavy stand of timber and underbrush
|
0.075
|
0.100
|
0.150
| |||
b.
|
Mountain streams, no vegetation in channel,
banks usually steep, trees and brush along banks submerged at high
stages
| ||||||
1.
|
Bottom: gravels, cobbles, and few boulders
|
0.030
|
0.040
|
0.050
| |||
2.
|
Bottom: cobbles with large boulders
|
0.040
|
0.050
|
0.070
| |||
D-2.
|
Floodplains
| ||||||
a.
|
Pasture, no brush
| ||||||
1.
|
Short grass
|
0.025
|
0.030
|
0.035
| |||
2.
|
High grass
|
0.030
|
0.035
|
0.050
| |||
b.
|
Cultivated areas
| ||||||
1.
|
No crop
|
0.020
|
0.030
|
0.040
| |||
2.
|
Mature row crops
|
0.025
|
0.035
|
0.045
| |||
3.
|
Mature field crops
|
0.030
|
0.040
|
0.050
| |||
c.
|
Brush
| ||||||
1.
|
Scattered brush, heavy weeds
|
0.035
|
0.050
|
0.070
| |||
2.
|
Light brush and trees in winter
|
0.035
|
0.050
|
0.060
| |||
3.
|
Light brush and trees, in summer
|
0.040
|
0.060
|
0.080
| |||
4.
|
Medium to dense brush, in winter
|
0.045
|
0.070
|
0.110
| |||
5.
|
Medium to dense brush, in summer
|
0.070
|
0.100
|
0.160
| |||
d.
|
Trees
| ||||||
1.
|
Dense willows, summer, straight
|
0.110
|
0.150
|
0.200
| |||
2.
|
Cleared land with tree stumps, no sprouts
|
0.030
|
0.040
|
0.050
| |||
3.
|
Same as above, but with heavy growth of sprouts
|
0.050
|
0.060
|
0.080
| |||
4.
|
Heavy stand of timber, a few down trees, little
undergrowth, flood stage below branches
|
0.080
|
0.100
|
0.120
| |||
5.
|
Same as above, but with flood stage reaching
branches
|
0.100
|
0.120
|
0.160
| |||
D-3.
|
Major streams (top width at flood stage 100
ft). The n value is less than that for minor streams of similar description,
because banks offer less effective resistance.
| ||||||
a.
|
Regular section with no boulders or brush
|
0.025
|
—
|
0.060
| |||
b.
|
Irregular and rough section
|
0.035
|
—
|
0.100
|
Exhibit 9-19
Permissible Velocities for Swales, Open
Channels, and Ditches with
Uniform Stands of Various Well-Maintained
Grass Covers
| |||
---|---|---|---|
Cover
|
Slope Range2(percent)
|
Permissible Velocity1
| |
Erosion Resistant Soils
(feet per second)
|
Easily Eroded Soils
(feet per second)
| ||
Bermudagrass
|
0 to 5
|
8
|
6
|
5 to 10
|
7
|
5
| |
Over 10
|
6
|
4
| |
Bahia
|
0 to 5
5 to 10
Over 10
|
7
6
5
|
5
4
3
|
Buffalograss
| |||
Kentucky bluegrass
| |||
Smooth brome
| |||
Blue grama
| |||
Tall fescue
| |||
Grass mixtures
|
0 to 52
|
5
|
4
|
Reed canarygrass
|
5 to 10
|
4
|
3
|
Lespedeza sericea
|
0 to 53
|
3.5
|
2.5
|
Weeping lovegrass
| |||
Yellow bluestem
| |||
Redtop
| |||
Alfalfa
| |||
Red fescue
| |||
Common lespedeza4
|
0 to 55
|
3.5
|
2.5
|
Sudangrass4
|
NOTES:
| |
---|---|
1
|
Use velocities exceeding five feet per second
only where good covers and proper maintenance can be obtained.
|
2
|
Do not use on slopes steeper than 10% except
for vegetated side slopes in combination with a stone, concrete, or
highly resistant vegetative center section.
|
3
|
Do not use on slopes steeper than 5% except
for vegetated side slopes in combination with a stone, concrete, or
highly resistant vegetative center section.
|
4
|
Annuals—use on mild slopes or as temporary
protection until permanent covers are established.
|
5
|
Use on slopes steeper than 5% is not recommended.
|
Pipe Diameter
(inches)
|
ASTM Class Pipe
|
Minimum Cover
(surface to top of pipe)
(inches)
|
Pipe Diameter
(inches)
|
ASTM Class Pipe
|
Minimum Cover
(surface to top of pipe)
(inches)
|
---|---|---|---|---|---|
12
|
III
|
17
|
24
|
III
|
15
|
IV
|
12
|
IV
|
6
| ||
V
|
7
|
V
|
6
| ||
15
|
III
|
16
|
30
|
III
|
10
|
IV
|
11
|
IV
|
6
| ||
V
| |||||
18
|
III
|
16
|
36 and above
|
III
|
6
|
IV
|
10
|
IV
|
6
| ||
V
|
6
|
Inlet Type
|
Inlet Size
(interior)
(inches)
|
Cambell Foundry No.
(or approved equal)
| |
---|---|---|---|
"A"
|
24 x 42
|
3405
| |
"B"
|
48 x 42
|
2618
| |
"D"
|
24 x 42
|
2617
| |
"E"
|
48 x 42
|
3425
|
Pipe Size
(inches)
|
Manhole Spacing
(feet)
| |
---|---|---|
15 or less
|
500
| |
18 to 36
|
600
| |
42 to 60
|
700
| |
60+
|
700+
|
Minimum Top Widths
| ||
---|---|---|
Height
(feet)
|
Top Width
(feet)
| |
0 to 15
|
10
| |
15 to 20
|
12
| |
20 to 35
|
14
|
Size of Storage Area*
| ||||
---|---|---|---|---|
Elevation
(feet)
|
0 to 15 Square Miles
|
15 to 100 Square Miles
|
100+ Square Miles
| |
Less than 2 below
|
40%
|
65%
|
90%
| |
Between 2 and 4 below
|
25%
|
50%
|
75%
| |
Over 4 below
|
10%
|
25%
|
50%
|
NOTE:
| ||
---|---|---|
*
|
Area contributing floodwaters to the flood hazard
area at the site in question.
|