2008-2009 Training Presentation

1. BMP Training Module 2
Extended Wet Detention Basin
& Extended Detention Wetlands
Sponsored by: MARC
Presenters:
Andy Sauer, P.E. (CDM)
Natalie Postel, P.E. (CDM)
December 12, 2008
A

2. Agenda







8:30-9:20 Lecture 1: Overview of Extended Detention and Wetlands

Review Module 1 and WQv definition

Define “Extended Detention”

Define Extended Wet Detention and Extended Detention Wetlands
10 minute break
9:30-10:30 Lecture 2: Design Examples

Extended Wet Detention Basin

Extended Detention Wetland
15 minute break
10:45 – 11:30 Design Activity
11:30 – 11:45 Design Activity Results
11:45 – 12:00 Lecture 3: Other considerations

Implementation

Operations and maintenance

Vegetation

Lessons learned
A

3. Best Management Practice
(BMP)



Best – State of the Practice
 No definitive answer
 Past experience, testing, research,
 Unique to site
Management – Responsible Parties

Improve water quality, meet NPDES Phase II
 Jurisdictional specific

Meet specific requirements of a regional
Practice – Action or Implementation

Practice = defined to carry out, apply, or to
do or perform often.
A

4. Basic BMP Principles

Plan for stormwater management




Mimic natural hydrology



Sustainable and “be green”
Provide a level of service
Improve water quality
Increase initial abstraction
Promote infiltration, retention & ET
“Treat” the stormwater runoff


Natural processes
Treatment trains
A

5. BMP Evaluation Process
PLAN
MIMIC
TREAT
Extended detention
(40 hours) to
increase treatment
and decrease peak
flows
A

6. TREAT
Detention and Treatment

Structural BMPs
detain runoff

Extended Detention
Basins
• Wet
• Dry



Extended Detention
Wetlands
Infiltration basins
Typically used as
larger, centralized
facilities
Topeka KS
A

7. Example site
l
ne
n
ha
C
in
Ma
Design Documents
e
i dg
Br
– APWA 5600
– BMP Manual
– Watershed
Master Plans
TREAT
Commercial
Building
BioFilters
Wet
Pond
Grass Swale
Streambank
Biostabilization
Culvert
Roa
d
w ay
A

8. Structural BMP Consideration









Pollutant removal efficiency
Water quality volume
Site suitability
Tributary area
Dimensions (depth, length-width ratio)
Outlet
Emergency spillway
Maintenance easement
Routine and non-routine maintenance
A

9. an
Qu
er
er
Aesthetics/Amenity
y
tit
W
at
at
W
Qu
ali
ty
BMP Evaluation
General Rule
A

10. BMP Manual
A

11. Post Development BMP
Selection
A

12. BMP Selection Flowchart
Level Of Service
BMP Value Rating
Water Quality
Volume/sizing
Placement,
maintenance
A

13. Water Quality Volume (WQv)

Water Quality Volume
(WQv): The storage needed
to capture and treat 90% of
the average annual storm
runoff volume

Water Quality Storm: The
storm event that produces ≤
90% volume of all daily
storms in a year

WQv
Extended detention and
wetlands sizing is based on
the WQv
A

14. Kansas City Water Quality
Storm
Young and McEnroe
(http://kcmetro.apwa.net)
Daily Precipitation (in)
A
2.
7
2.
5
2.
3
1.
9
2.
1
1.
5
1.
7
1.
1
1.
3
0.
5
0.
7
0.
9
45
40
35
30
25
20
15
10
5
0
0.
1
0.
3
Water Quality
Storm = 1.37 in
# of days > or=
2003 Kansas City Precip events

15. Why Use the WQv to size
BMP?

Retain runoff long enough to get
water quality benefits

Reducing erosive flows from
smaller runoff events
A

16. Water Quality Volume
Calculation

Two methods

Short-Cut Method
•
•

Sites < 10 acres
Only 1 predominant cover type
Small Storm Hydrology Method
•
Larger or more heterogeneous drainage
areas
A

17. WQv Calculation

Short-Cut Method
WQv = P*Rv



P = 24 hour Water Quality Storm (inches)
Rv = Volumetric run coefficient =
0.05+0.009(I)
I = % site Imperviousness
A

18. WQv Calculation

Small Storm Hydrology Method
WQv = P*Weighted Rv



Weighted Rv = Σ(Rvi*Aci)/Total area (ac)
Rvi = Volumetric runoff coefficient for cover
type (table)
Aci = Area of cover type i (ac)
A

19. Questions?
A

20. Why the term “Extended”
Detention?
Extended: Designed to release the WQv over a period
of 40 hours



Allows time for more particles and associated
pollutants to settle out
Reduces the downstream velocity and erosive
conditions
More closely imitates natural release rates and
duration
A

21. Geomorphic Effects of
Uncontrolled Urban Runoff
A

22. Flow Frequency for
Detention
1000
Developed
Uncontrolled
7-yr
2/yr
6/yr
100
Flow
20/yr
10
Undeveloped
1
0.1
§
·
q·
more frequent than 1-yr
B
1-yr
2-yr
Storm Return Interval
Ú
10-yr
100-yr
y·
A

23. 40-Hour Drawdown Impacts
1000
Developed
Uncontrolled
100
Flow
0.80 psf
Developed
Controlled
10
0.26 psf
•10-year control
•1-year control
•WQv – extended
detention with 40 hr
drawdown
1
Undeveloped
0.1
0.01
0.1
more frequent than 1-yr
1
1-yr
2-yr
Storm Return Interval
10
10-yr
100
100-yr
A

24. BMP Manual
Extended Detention

Water Quality (40-hr)

Pollutant removal through
• Settling
• Biological uptake (more for
wetland)
• Permanent Pool
• WQv = Volume above the
permanent pool

Stream Sustainability (40-hr)


Mimic undeveloped
conditions for full range of
hydrology
Can meet flood control
objectives
A

25. Extended Wet Detention Basin (EWDB)
A

26. EWDB Littoral Bench
Littoral
Bench
A

27. EWDB Littoral Bench

Provides water quality
treatment

Mild slope serves as
safety feature around
perimeter of permanent
pool

25% to 50% of
permanent pool surface
area

Helps control geese
access
Topeka, KS
A

28. EWDB Permanent Pool
A

29. EWDB Permanent Pool





Water quality volume
(WQv) mixes with
permanent pool
WQv released over 40
hours
Minimum depth of 6-ft
Residence time of 14
days
Significantly more
water quality benefit
than EDDB
Topeka, KS
A

30. EWDB Outlet Structure




Release the WQv over a period of
40 hours
Protected by well screens, trash
racks or grates
Located as far from inlet as
possible
Various outlet structure options



Single Orifice
Perforated Riser or Plate
V-notch Weir
Source: Hubbard Brook LTER
A

31. Extended Detention
A

32. EWDB Vegetation



Upland area: Native
grasses (preferable) or
turf on berms and side
slopes
Littoral Zone: Native
wetland species
Recommend 3-5 native
species
Kansas City, MO
Soft Rush, Juncus effusus
A

33. EWDB Siting Considerations





Off-line, outside of stream corridor
EWDBs can be located within larger flood
control facilities
Minimum 20 feet setback
Not on fill sites or steep slopes (unless
enhanced)
Use fences and landscaping to impede access
areas to address public safety concerns

Outflow structure shall be fenced
A

34. Questions on Extended Wet
Detention Basin (EWDB)?
A

35. Extended Detention Wetland (EDW)
A

36. EWD Permanent Pool
Permanent pool extends throughout wetland
A

37. Extended Detention Wetland
(EDW)
Forebay
A

38. EDW Forebay



Same function as
EWDB
Should hold at least
10% of the WQv
Separated from the
wetland by a earth
weir, gabion or loose
riprap wall
Topeka, KS
A

39. EDW Marsh
Marsh


Pollutant removal through plant root systems
Shallower than EWDB permanent pool
A

40. EDW Micropool
Micropool
Reverse slope pipe under the surface of the micropool is
used to prevent clogging
A

41. EDW Micropool




Prevents outlet clogging
Allows further settling of
sediment
Should have a capacity of
at least 10% of WQv
Surrounded with a safety
bench
A

42. EDW Outlet Structure, Outfall,
and Emergency Spillway
A

43. EDW Vegetation




Vegetation should cover 50-75% of surface area
3-5 native species are recommended
Select species based on stress tolerance and ability
to handle variations in water availability
Consult local experts
Lenexa, KS
Topeka, KS
Topeka, KS
A

44. EDW Siting Considerations



Off-line, outside of stream corridor
Perform water budget analysis to ensure
permanent pool
Soils should be suited for wetland species



Hydric soils with high phosphorous affinity
Not on fill sites or steep slopes (unless
enhanced)
Use fences and landscaping to impede
access areas of public safety concern

Outflow structure shall be fenced
A

45. Extended Wet Detention
versus
Extended Detention Wetlands
Similarities
 Water quality volume mixes with
permanent pool

40 hour drawdown of water quality
volume (WQv)
Differences
 Depth of permanent pool (18 inches in
wetland vs. 6 to 12 feet in basin)
 Vegetation types and planting
configurations
A

46. Advantages
and
Disadvantages
A

47. EWDB Advantages

Settling of suspended
solids

Pollutant uptake by pond
vegetation

Flood control via peak
discharge attenuation

Control of channel erosion
by reducing downstream
flow velocities

Creation of wildlife habitat

Recreational and aesthetic
benefits
Topeka, KS
A

48. EDW Advantages







Settling of suspended solids
Pollutant uptake by wetland
vegetation
Flood control via peak
discharge attenuation
Control of channel erosion
by reducing downstream
flow velocities
Creation of wildlife and
aquatic habitats
Recreational and aesthetic
benefits
Some groundwater recharge
A

49. EWDB Disadvantages

Potential safety concerns

Additional maintenance due to
sediment removal, floating
trash, scum, and algal blooms

Potential odor problems

Need conditions to sustain
permanent pool

Resident waterfowl can
become a source of fecal
coliform and nutrients

Vector issues may result in
additional maintenance
requirements
A

50. EDW Disadvantages





Require more space, due
to shallower depth of
water storage
Additional maintenance
due to vegetation
overgrowth
Requires larger drainage
area to sustain permanent
pool
Vector issues can result in
increased maintenance
requirements
Site limitations in urban
areas
A

51. Questions?
Break 10 minute
A

52. Lecture 2
Design of EWDB EDW

Discuss key design features

Introduce calculations for each major
component

Perform example calculations
A

53. Extended Wet Detention Basin
Key Design Features



Water quality storage volume
Permanent pool
Outlet structures








Orifice
Perforated riser or plate
V-notch weir
Pool shape
Basin shape
Forebay
Littoral bench
Vegetation
Topeka, KS
A

54. Design Example


26 acre drainage
Land use






1.6 acres of flat
roofs
8.8 acres of parking
lot
3.3 acres of narrow
streets
12.3 acres of silty
soil
53 % impervious
Outlet Structure
designed for 40 hour
release of WQv
New Development Site
A

55. Water Quality Storage Volume
EWDB Design Procedure Form
i.
ii.
Tributary area = 26 acres
Calculate water quality storage volume
A

56. Water Quality Storage Volume
ii.
Calculate Water Quality Storage
Volume (WQv)
Two methods

Short-Cut Method
•
•

Sites 10 acres
Only 1 predominant cover type
Small Storm Hydrology Method
•
Larger or more heterogeneous
drainage areas
A

57. Water Quality Storage Volume
Short-Cut Method
WQv = P*Rv

P = 24 hour Water Quality Storm (inches)
P = 1.37 inches (Kansas City)


Rv = Volumetric run coefficient = 0.05+0.009(I)
I = % site imperviousness
A

58. Water Quality Storage Volume
Small Storm Hydrology Method
WQv = (P)*(Weighted Rv)
Weighted Rv = Σ(Rvi*Aci)/Total area (ac)
•
•
Rvi = Volumetric runoff coefficient for cover type
(table)
Aci = Area of cover type i (ac)
A

59. Rv Table
TABLE 7
VOLUMETRIC COEFFICIENTS FOR URBAN RUNOFF FOR
DIRECTLY CONNECTED IMPERVIOUS AREAS
(CLAYTOR AND SCHUELER 1996)
Rainfall
(inches)
Flat roofs and
large unpaved
parking lots
Pitched roofs and
large impervious
areas
(large parking lots)
Small
impervious
areas and
narrow
streets
Silty
soils
HSG-B
Clayey soils
HSG-C and
D
0.75
0.82
0.97
0.66
0.11
0.20
1.00
0.84
0.97
0.70
0.11
0.21
1.25
0.86
0.98
0.74
0.13
0.22
1.37
0.87
0.98
0.75
0.14
0.23
1.50
0.88
0.99
0.77
0.15
0.24
Note: a reduction factor may be applied to the Rv values for disconnected
surfaces, consult the BMP hydrology section
A

60. Water Quality Control Volume
Cover Type
Rv
Area (acres)
Flat roofs
0.87
1.6
Parking lots
0.98
8.8
Narrow streets
0.75
3.3
Silty soil
0.14
12.3
Rvi × Aci
WQv = ∑
×P=
Total Area
∑ ( .87 × 1.6 + .98 × 8.8 + .75 × 3.3 + .14 × 12.3) × 1.37 = 0.749in
26
A

61. Water Quality Storage Volume

Convert WQv from inches to ac-ft by converting
inches to feet and multiplying by the tributary
area
= (0.749in)*(1ft/12in)*26ac
A

62. Permanent Pool
Permanent Pool
A

63. Permanent Pool





Average pool depth 4 to
6 feet (not to exceed
12 feet)
A portion of the pool
must be at least 10 feet
if the pool is to contain
fish
At least 5.5 acres of
tributary area per ac-ft
of permanent pool
At least 10.3 acres of
tributary area per acre
of pool surface area
14 day residence time
A

64. Permanent Pool Volume (Pv)
Method 1

Based on the time required for algae to uptake
sufficient phosphorous
VP1 = (C * AT * R14) / 12




C = Runoff coefficient = 0.3 +0.6*I or APWA
section 5602.3
I = Fraction of impervious area
R14 = 14-day wet season rainfall
At = total tributary acreage
A

65. Permanent Pool Volume (Pv)
Method 2

Based on the time required for suspended
solids to settle
VP2 = (VB/VR * SD * Ai) / 12



VB/VR = ratio of design water quality volume
to runoff volume (should be at least 4 for
adequate TSS removal)
SD = mean storm depth
Ai = impervious tributary acreage
A

66. Permanent Pool Volume (Pv)
Method 1
Kansas City
From APWA section 5602.3
= 0.3+0.6*.53
= (0.6*26*2.2)/12
A

67. Permanent Pool Volume (Pv)
Method 2
~93%
VB/R=5
Figure 24
A

68. Permanent Pool Volume (Pv)
Method 2
5.0
Kansas City
0.6
13.7
= (5.0*0.6*13.7)/12
3.43
Correction: Step 1 should refer to Figure 24
A

69. Permanent Pool Volume (Pv)
= 3.43*1.20
1.
2.
3.
Use the larger volume calculated in the
previous steps and add 20% for sedimentation
Average pool depth: 4 to 6ft
Surface area = VP / ZP
A

70. Outlet Structure
Single Orifice
V-notch Wei
Perforated Riser or Plate
A

71. Outlet Structure


Outlet sized to release
WQv (ac-ft) within 40
hours
Locate outlet as far
away from inlet as
possible



Avoid short-circuiting
The facility must
bypass 1% storm event
Provide at least 1ft of
freeboard above WQV
stage
A

72. Single Orifice Outlet
A

73. Single Orifice Outlet
i.
Depth of water quality volume at outlet (ZWQ)
ZWQ = 3 feet
ii.
Average head of WQv over invert of orifice,
HWQ (ft)
HWQ = 0.5*ZWQ
iii.
Average water quality outflow rate, QWQ (cfs)
QWQ = (WQV * 43,560) / (40 * 3,600)
A

74. Single Orifice Outlet
= 0.5*3.0ft
= (1.62*43,560)/(40*3600)
A

75. Single Orifice Outlet
iv. Set orifice coefficient
(Co) depending on
orifice plate thickness
u
u
u
Do must be greater than
4 inches in the following
step
C0 = 0.66 if plate
thickness is Do
C0 = 0.80 if Do
A

76. Single Orifice Outlet
v.
Orifice diameter (Do) must be greater than 4
inches, otherwise use weir or riser
Do = 12 * 2 * QWQ / Co * π *
(
2 * g * HWQ
)
g=32.2 ft/sec2
π = 3.14
A

77. Single Orifice Outlet
Do=12*2*(0.49/(0.66*π*(2*32.2*1.5)0.5))0.5
A

78. Perforated Riser or Plate
Outlet
Photo taken by Larry Roesner
Photo taken by Larry Roesner
A

79. Perforated Riser or Plate
Outlet
A

80. Perforated Riser or Plate
Outlet

Calculate outlet area per row of
perforations (Ao)
Ao (in2) = WQv / (0.013 * ZWQ2 + 0.22 * ZWQ – 0.1)

Assuming a single column, calculate
the diameter of a single perforation for
each row
D1 = (4 * Ao / π)1/2

If D1 is greater than 2 inches add more
columns
nc = 4
A

81. Perforated Riser or Plate
Outlet
3.0
2.4
= 1.62/(0.013*3.02+0.22*3.0–0.1)
1.75
= (4*2.4/π)1/2
1
1.75
NA
9
A

82. Perforated Riser or Plate
Outlet

Use number of columns to determine exact
perforation diameter
Dperf = (4 / π * Ao / nc)1/2

Using a 4” center to center vertical spacing
and ZWQ, determine number of rows (nv)
nv = ZWQ / 4
nv = 5
A

83. Perforated Riser or Plate
Outlet
3.0
2.4
= 1.62/(0.013*3.02+0.22*3.0–0.1)
1.75
= (4*2.4/π)1/2
1
1.75
= (4/π*2.4/1)1/2
= (ZWQ*12in)/4
NA
9
A

84. V-Notch Weir Outlet
Dr. Robert Pitt
Source: Hubbard Brook LTER
A

85. V-Notch Weir Outlet
= 0.5*3.0ft
= (1.62*43,560)/(40*3600)
A

86. V-Notch Weir Outlet

Calculate required v-notch weir angle
(calculator in radians)
θ = 2 * (180 / π) * arctan (QWQ/(Cv * HWQ5/2))
CV = V-notch weir coefficient = 2.5
If calculator is set to degrees use
θ = 2* arctan (QWQ/(Cv * HWQ5/2))
θ
Source: Hubbard Brook
LTER
A

87. V-Notch Weir Outlet

If θ is 20º set θ to 20º

Calculate top width of v-notch weir
(WV)
θ
Wv = 2 * ZWQ * Tan (θ / 2)
Source: Hubbard Brook
LTER
A

88. V-Notch Weir Outlet
= 2*(180/π)*arctan(0.49/(2.5*1.55/2))
= 2*3.0*tan(8º/2)

Since θ 20º set θ to 20º
A

89. Pool Shape
W
3W
A

90. Water Budget


Recommended to
ensure permanent
pool
Chapter 13 the
NRCS Engineering
Hand Book
∆storage
= Qin − Qout
∆time
A

91. Forebay

Volume (VolFB) should be at least 10% of WQv

Depth (ZFB) should be at least 3feet

Sides and bottom paved or hardened
Surface area (AFB):

AFB = VolFB / ZFB
A

92. Forebay
= 0.10*1.62
= 0.16/3.0
Topeka KS
A

93. Littoral Bench




Serves as a planting
surface and safety
feature around
perimeter of permanent
pool
25% to 50% of
permanent pool
surface area
At least 10 feet wide
with a max slope of 6:1
6 to 12 inches below
permanent pool water
surface
A

94. Littoral Bench
Width of Littoral Bench (WLB):
WLB
A LB ( 43,560 )
=
A Pool ( 43,560 )
2π
π
A

95. Littoral Bench
Min=0.25*0.82, Max=0.5*0.82
Min= (0.21*43560)/(2π*(0.82*43560/ π)1/2)
Between WLBMin and WLBMax
A

96. Vegetation




Plant berms and
sloped areas with
native grasses
Littoral bench should
be planted with native
wetland species
Plant trees and shrubs
around perimeter of
site
Appendix A in BMP
manual
A

97. Questions?
A

98. Extended Detention Wetland
Key Design Features

Permanent
pool







Low marsh
High marsh
Forebay
Micropool
Outlet structure
Water budget
Wetland shape
A

99. Extended Detention Wetland
Permanent Pool Volume

Use Method 1 or Method 2 – same as in Extended
Wet Detention Basin Design

Choose larger volume as permanent pool volume.
A

100. Extended Detention Wetland
(EDW)
0-6 in
4-6 ft
4-6 ft
6-18 in
A

101. Permanent Pool
Design Volume Allocations
20%
20%
20%
40%
A

102. Permanent Pool
Design Volume Allocations
= 4.1*0.2
= 4.1*0.2
= 4.1*0.4
= 4.1*0.2
A

103. Forebay Considerations

Pre-sedimentation at entry to EDW


Capacity to contain 5 years of
sediment
Separated from EDW with berm,
gabion, or riprap
A

104. EDW Forebay

Use VForebay from step II and SAForebay from step III to
find forebay depth (ZForebay)
ZForebay = VForebay/SAForebay

Depth should be 4-6feet
A

105. EDW Forebay
A

106. Micropool Considerations



Prevents clogging of outlet
4-6 feet deep
Should be surrounded by a safety shelf
A

107. EDW Micropool

Using the same method used to calculate the
forebay:
ZMicropool = VMicropool/SAMicrpool

Depth should be 4 to 6 feet

Safety bench should be ≥ 12 feet
A

108. EDW
Water Quality Outlet

Depth of water quality volume above permanent
pool




Consider survivability of plant species
Maximum depth should be 2 feet or less
Single Orifice, Orifice Plate or Standpipe, and Vnotch outlet examples in Manual
Sized for 40 hour drawdown
A

109. Shape
Flowpath length (L) to permanent pool width (W)
ratio must be greater than 3:1
 Place berms or high marsh wedges at 50-foot
intervals perpendicular to the flow direction to
increase dry weather flowpath length
 Wedge-shaped, narrowest at the inlet and widest
at the outlet

L
W
A

110. Vegetation

Wetland vegetation should occupy 50-75% of surface
area

Develop a landscaping plan, which places appropriate
species in each EDW zone and the surrounding area

For plantings, use soil from an existing wetland or a
designed wetland planting mix
Kansas City, MO
A

111. Questions?
15 minute break
A

112. Design Activity
UMKC Rain Garden Project
A

113. Activity
Design an extended wet detention basin to capture
runoff from a 42 acre drainage area with mixed land
use. Size the permanent pool and WQv of the basin
using a v-notch outlet structure that will release the
WQv over a period of 40 hours.
A

114. Activity - Design an EWDB
A

115. Activity Results
A

116. Lecture 3
Other Consideration



Vegetation
Operations and maintenance
Implementation




Planning
Design
Construction
Lesson’s learned
A

117. Vegetation


Process

Design

Review

Standards

Construction

Adaptive Management
Maintenance
Buy-in

Project Sponsor

Public/Stakeholders


Education

Aesthetics

Establishment

Benefits and challenges
Success

Realistic
A

118. Vegetation


Use plants listed in the BMP Manual Appendix A
“Recommended Plant Materials for BMPs”
Narrow down from this list by:

Treatment only, habitat creation / biodiversity,
aesthetics?
• If treatment is most important, then a wetland seed
mix may be sufficient.
• If habitat creation and biodiversity is desired, specific
species with habitat benefits are recommended

Evaluating site conditions - soil quality, climate,
wetness, pollution
• Hardier plants would work better in areas with poorer
site conditions
A

119. Vegetation

Narrow down from this list by (cont):

Speaking with local nursery or botanists
•
•
•

What plants are available for purchase?
Which plants have the best survivability?
Which plants would be best candidates for wet areas,
variable moisture, poor soils, etc.?
Visit at natural wetland in the area
• What plants are naturally favored in local area?
• Are there specific invasive species that need to be
managed?

Check municipal codes to ensure all plant materials
are approved for the area
A

120. Wetland Species
A

121. Nuisance Species
A

122. Nuisance Species
A

123. Native versus Non-native
Plants

Native plants are
recommended
 Larger root system

Increase infiltration

More drought
tolerant
 Disease resistant
 Adapted to
environment
A

124. Native Plants-Advantages and
Disadvantages
Advantages
 Indigenous to the area and able to thrive in the local climate with
less maintenance.
 Deep roots enhance stormwater infiltration into the soil.
 Able to withstand flooding events as well as extended dry
periods.
 Reduces flow velocity of stormwater runoff.
 Wide range of application (restoration of native prairie, woodland,
wetlands, riparian areas)
 Attracts wildlife and improves biological diversity.
 Requires little to no fertilizer or chemical maintenance
 Requires less water to survive.
 Provides attractive and natural vegetative scenery.
Disadvantages
 Can be difficult to establish if some circumstances.
 Can be expenses if planted from nursery stock plugs.
 Can be considered “weedy” by some people.
A

125. Vegetation – Design
Consideration









Local and regional planning initiatives
Public involvement/public relations
Visibility-Aesthetics
Height of vegetation
Financial (funding source, budget, property values)
Regulatory requirements
Function/risk
Utility-stormwater management
Recreation
A

126. Vegetation Resources
http://plants.usda.gov




Appendix A in the MARC BMP manual
Local nurseries
www.kansasnativeplantsociety.org
www.grownative.org
A

127. Other Sources

Tallgrass Restoration Handbook for Prairies Savannas and
Woodlands (Packard Mutel, 1997)

The National List of Plant Species that Occur in WetlandsRegion 3 (USFWS, 1988)

The Flora of Missouri (Steyermark, 1963; 1996)

Steyermark’s Flora of Missouri, Volume I, II,…; Yatskeievych;
1999…)

The Flora of the Great Plains (McGregor et. al.)

Ecologist; Landscape Architect
A

128. Vegetation Examples

Banks

Butterfly Milkweed,
Asclepias tuberosa
Clarence A. Rechenthin @ USDA-NRCS PLANTS Database

Littoral Bench

Blunt Spikerush,
Eleocharis obtusa
Robert H. Mohlenbrock @ USDA-NRCS PLANTS Database
A

129. Vegetation – Other Design
Consideration

Setting



Built Environment





Urban
Rural
Commercial
Residential
Mixed Use
Stormwater Utility – Stormwater Management
Recreation
CONTEXT
A

130. Vegetation – Installation
Maintenance


Installation

Oversight

Contractor Experience

Plant availability
Maintenance Measures

Has a maintenance program/budget been established?

What type of adaptive management will be implemented?
• Burning or mowing
• Herbicides
• Transplanting

Who will do the management-establishment?
• Lawn maintenance crews
• Native Landscape specialists
A

131. General Maintenance




Event Inspection ( 0.5 inches)

Inspect facility operation, especially outlet structure

Remove trash debris

Document potential problems
Monthly Inspection

Inspect repair erosion

Water plant material during dry periods (1st Year)
 Perform routine plant maintenance (pruning, weeding, etc.)
Semi-Annual Inspection

Remove and replace dead or diseased vegetation

Re-landscape/re-mulch any area areas
Annual Inspection

Inspect inlet outlet structure condition

Record assessment of planted species evidence of invasive
plant species

A
Perform comprehensive safety inspection

132. Other Maintenance
Consideration





Maintenance access - 15
feet wide strip around
the perimeter of the site
May need to harvest
excess plants
Erosion issues
Sediment removal from
forebay when 50% full
Sediment removal from
micropool and marsh
area when 10 to 15% full
A

133. Designer
Review Team
Planning Phase
– Environmental Site
Assessment
– Select Post
Construction BMPs
– Flood Control Study
– Establish Long-term
Maintenance Agreements
Plat
Approval
Planning
Engineering
Parks Recreation
Environmental Specialists
Attorney
Design Phase
– Erosion and
sedimentation
controls
– Post-construction
BMPs
– Flood control
improvements
Building
Permit
Review Team
Planning
Engineering
Code Compliance
Inspectors
Review Team
Planning
Engineering
Parks Recreation
Environmental Specialists
Operations Maintenance
Construction Phase
– Inspect and maintain
BMPs for construction
activities
– Construct Post
Construction BMPs
– Maintain agreements for
post-construction BMPs
Occupancy
Permit

134. Upcoming Training Sessions

Module #3 – Rain Gardens Bioretention



Date: January 23, 2009
Location: Helzberg Auditorium, KCPL
Module #4 – Extended Dry Detention Infiltration
(Pervious Pavements)


Date: February 20, 2009
Location: Helzberg Auditorium, KCPL
A

135. Questions?
Comments.
Suggestions.
A