Presentation at the Oregon Landscape Contractors Association 2011 Expo. Describes common issues and approaches to maintenance tasks in LID facilities.

1. Maintenance of Rain Gardens, Swales, and
Stormwater Planters
OLCA Expo
December 1, 2011

2. Partners
Candace Stoughton EMSWCD
Gail Shaloum Clackamas WES
Rob Emanuel Clean Water Services
Damon Richardson Pacific Sports Turf
Henry Stevens Portland BES
Maria Cahill Green Girl Land Development

3. Agenda
• What is stormwater? Why manage it?
• Legal issues
• Role for landscape contractors
• Types of facilities
• Maintenance activities
• Vegetation
• Pests
• Irrigation
• Soils/Mulch
• Structures
• Erosion Control
• Spills/Trash
• Take home messages

4. What is Stormwater?
Photo: morgueFile
Rainfall and snowmelt that runs off instead of seeping
into the ground.

5. Sources of stormwater?
Roofs Driveways
Streets Parking Lots
Rainfall and snowmelt that runs off instead of seeping
into the ground.

6. Water cycle
More Runoff
Arriving Faster

7. Stormwater
Photo: East Portland News
Can cause unnatural flooding

8. Stormwater
Photo: morgueFile
Photo: East Portland News Photo: Johnson Creek Watershed Council
Can degrade streams

9. Stormwater
Carries pollutants to waterways

10. Video
Poisoned water-20111027-155559_678.mp4

11. Rain garden-municipal
Photo: EMSWCD
Planted landscape facility designed to collect and absorb
runoff and filter out pollutants.

12. Swales (aka bioswales)
Long, planted, open channel that carries, slows
stormwater and filters out pollutants.

13. Rain garden-residential
Photo: EMSWCD
Planted landscape facility designed to collect and absorb
runoff and filter out pollutants.

14. Stormwater planter
Structural landscape reservoir designed to filter out
pollutants, and in some cases, infiltrate stormwater.

15. Stormwater planter/green street

16. Function
Graphic: EMSWCD

17. Anatomy-Infiltration planter

18. Anatomy-Flow through planter

19. What is involved?
• Facilities need inspection and maintenance
(annually, or more)
• Maintenance includes:
• hydrologic and water
quality function
• landscape functions
• impacts on human health
and safety

20. Business opportunity
Specialized training to design, inspect and maintain
• Landscape Architects
P
• Civil Engineers
• Landscape Designers
• Landscape Contractors
• Green industry professionals
Example:
City of Portland
• 9000 stormwater facilities
• ≈ ¼ are LID facilities

21. Legal roles and responsibilities
EPA
(US Clean Water Act)
ODEQ
Jurisdiction
Facility
Owner Contractor

22. Maintenance agreements

23. Inspection log
• Each jurisdiction will have
different requirements for
inspections, reporting, etc.

24. General observations
Before you go…
• O & M plan or manual
• As-built or design report
• Locations of
inlets/outlets, plantings,
irrigation, historical
problems, previous
observations

25. General observations
Once you arrive…
• Current and recent weather conditions?
• Last rain event?
• Inlets and outlets clear?
• Banks stable?
• Draining as designed or short-cutting?
• Pavement in good condition?
• Animal damage?
• Can you access?
• Steep or uneven terrain?
• People entering/cutting through the facility?

26. Contributing area
• Trash
• Leaves
• Oily
• Gravel
• Sediment
• Street or parking lot
sweeping
• Fertilizer or pesticide use
• Other activities going on
upstream

27. Contributing area

28. Contributing area

29. Safety and access
Access
• Need to have access
• Flat or evenly sloped
• If fenced, trim
fenceline for 3 feet if
space allows
• Consider safety
before you begin (do
not enter flooded
facility)

30. Safety and access

31. Safety and access
Personal Protective Equipment (PPE)
• Sturdy boots
• Gloves, puncture resistant gloves
• Ear plugs/earmuffs if operating power equipment
• Eye protection when “weed wacking” or mechanical
trimming, handling large branches
• Long sleeved shirts and pants
• Hard hat if cutting
overhead
35

32. Safety and access
Other Equipment
• Rakes: to clean out under shrubs where you
can’t see
• Grabbers: for trash, sharp objects, or needles
• First aid kit

33. Safety and access
Public Safety
• Vehicle entrances/exits
• Where people walk through, create a path

34. Trash
• Remove trash to prevent clogging and contamination

35. O&M tasks related to vegetation
• Functions
• Moving
• Appearances
• Pests
• Irrigation

36. vegetation can be part of the solution……
vegetation can be part of the problem.…..…

37. Keeping up appearances

38. Planting plans

39. Aesthetics

40. Aesthetics

41. Aesthetics vs function

42. Keeping things moving

43. Keeping things moving

44. Inlets

45. Inlets

46. Shade and competition

47. What would you do?

48. Aesthetics

49. Aesthetics

50. Do’s and Don’ts for Plants
• Do strive to keep good plant cover in a WQF
• Do pay attention to facility design
• Do replace dead plants promptly
• Don’t overly trim grasses and grass-like plants
• Don’t let plants block water flow

51. keeping pests at bay

52. Principles of IPM
• Start with healthy plants
• Monitor and identify pests
• Be tolerant of some damage
• Choose the least toxic control first
• Combine techniques

53. Pests

54. Pests

55. Pests

56. Pests
Canada thistle (Cirsium arvense) Reed canary grass (Phalaris arundinacea)
Red clover (Trifolium pratense) Nightshade (Solanum dulcamara)

57. Pests
Field Bind Weed (Convolvulus sepium) Poison Hemlock (Conium maculatum)
Birdsfoot Trefoil (Convolvulus sepium) Armenian Blackberry (Rubus armenicus)

58. Pests
English Holly (Ilex aquifolium) Yellow Flag Iris (Iris pseudacorus)
Old Man’s Beard (Clematis vitalba) Policeman’s Helmet (Impatiens balsamorhiza)

59. Pests
Herb Robert (Geranium robertianum) Garlic Mustard (Alliaria petiolata)
Lesser Celandine (Ranunculus ficaria) Yellow Archangel (Lamiastrum galeobdolon)

60. Pests

61. Pests

62. Herbicides
• Avoid if at all possible!
• Follow the label directions carefully
• Do not apply in standing water
• Try to stay above water-line in facilities
• Never apply when rain is forecasted
• Apply during calm weather, cool weather

63. Herbicide use: discretion of local jurisdiction
Use herbicides when a pest is
uncontrollable by other, less toxic
means.

64. Herbicides
• DON’T reach for herbicides at the first sign of a
pest, make a plan!
• DON’T apply herbicides directly to water in a
WQF
• DO apply herbicides during dry weather (mostly
June-September)
• DO apply herbicides when a pest is uncontrollable
by other means

65. Irrigation
P
• Plants are critical to the function of LID facilities
• Irrigation is essential for plant establishment and health

66. Irrigation
• Irrigation especially important during establishment period
(approx. 2 yrs) (true for native plants as well)
P
• Temporary irrigation fine for facilities with vegetation
that can handle OR’s dry summers

67. Irrigation
High exposure areas can also require permanent
Irrigation after the establishment period.
P
• Areas near pavement
• Vast areas of minimal
shade or lots of
wind exposure
• areas prone to drought
or fire

68. Irrigation
Water Efficiency
• Hand watering and drip type irrigation systems
P
are the most efficient irrigation methods.
• Adjusting the irrigation heads should be done as
needed to ensure water is not wasted on hard
surfaces.
• Avoid irrigating when the plants do not need
water.

69. Irrigation
How to Irrigate
• Water must be applied in a manner that lets it
P
percolate into the soils and not run off the surface.
• Hand watering- Put as much down as possible until
water begins to migrate along surface. Then go to
the next plant.
Automated Systems
• Permanent
• Temporary
• Utilize several short watering times or cycle/soak.

70. Irrigation for Plant Establishment
1st Year
Full irrigation schedule during the dry season to
P
ensure good plant establishment.
2nd Year
Water less than previous year to encourage plants to
adapt to local climate.
3rd Year
Should be little need for irrigation.

71. Irrigation
Do:
• Irrigate heavily but infrequently
P
• Water in the early morning or evening
• Automate if possible
• Check automated systems weekly during the heavy
irrigation season
• Blow out any above ground system to winterize
Don’t:
• Allow runoff
• Over water
• Allow overspray
• Irrigate when unnecessary

72. Soils
Soilfoodweb.com

73. Soils
• Healthy soils hold
water, sediment, and
pollutants
• Too much sediment
(and compaction) will
clog the system
• Regular maintenance
will keep the facility
working as designed City of Portland Environmental Services

74. Soils
City of Portland Environmental Services

75. Soils
Maria Cahill

76. Soils
City of Portland Environmental Services

77. Soils
Maria Cahill

78. Soils
• Well-designed systems
capture sediment near
the entrances
• Sediment loads vary
by facility
• Regular visual checks
are the key
City of Portland Environmental Services

79. Soils
City of Portland Environmental Services

80. Soils
• Visit the facility at least twice a winter after big
storms
• Check sediment accumulations as you’re doing
routine maintenance
• Monitor draw-down rates – how long does it take
for standing water to disappear after the end of a
storm ?
• Make notes for future reference

81. Plants and sediment can reduce depth

82. When do You Need to Remove Sediment ?
• If 2-3 inches of
sediment
accumulates
• When draw-
down rates
exceed about 36
hours
• Don’t let things City of Portland Environmental Services
get out of
control (photo)

83. When do You Need to Remove Sediment ?
City of Portland Environmental Services

84. Soils: Removing Sediment
• Schedule all maintenance for dry weather unless
there’s an emergency
• Rakes and shovels (hand removal) are best to avoid
damaging the plants
• Be sure to loosen the underlying native soil
• If large equipment is needed avoid compacting the
soils
• If slow infiltration rates persist, remove the top
couple of inches of soil

85. When to Be Concerned….
Nccwep.org waynedaley.com

86. Soils: Sediment and Soil Disposal
• Check for evidence of contamination: color and smell
• In most cases stormwater sediment is not hazardous and
can be disposed of as solid waste.
• Places to be concerned: recycling facilities, fueling stations,
industrial storage areas, etc.
• If you have questions, contact DEQ at 503-229-5263.
• Or consult DEQ’s guidelines for hazardous waste at
http://www.deq.state.or.us/lq/hw/hwmanagement.htm

87. Mulch
• Suppresses weeds and
maintains soil moisture
• Is a surface for deposition
of sediment (for easy
sediment removal)
• Apply 2-3 inches after
planting, after removing
sediment, and any time
there are bare spots
• Common mulches:
medium hemlock,yard-
debris compost. Gravel
“mulch” is sometimes used
at entrances Maria Cahill

88. Mulch
• Mulch sometimes
floats in the first
storms just after
construction.
• Yard debris compost
is less prone to
floating, but it can
be a source of weeds
Maria Cahill
• Many LID systems
are densely planted
and need only spot-
mulching after the
first couple of years

89. Do’s and Don’ts
Do
• Visually monitor the facility on a regular basis
• Remove sediment when it reaches 2-3 inches
• Plan to take action if drawdown times exceed 36 hours
• Mulch and plant bare spots for erosion control
• Loosen the soil after removing sediment
Don’t
• Compact the soils by working in the facilities when the
soils are wet (wait until summer)
• Assume a facility is permanently clogged until steps have
been taken to remove sediment layers
• Handle soils that smell or look odd (contamination)

90. Structures
Prevent Erosion
• Rip rap vs. no erosion prevention

91. Structures
Remove Sediment & Debris
• Rip rap

92. Structures
Remove Sediment & Debris
• Shallow forebay

93. Structures
Remove Sediment & Debris
• Forebay with sump

94. Structures
Remove Sediment & Debris
• Curb cuts

95. Structures
Remove Sediment & Debris
• Flat outlets vs. beehive outlets

96. Structures
Prevent Excessive Ponding
• Under drains

97. Structures
Prevent Excessive Ponding & Flooding
• Overflows

98. Structures
Prevent Flooding
• Obstructions

99. Structures
Protect Structural Integrity
• Curb damage

100. Structures
Protect Structural Integrity
• Walls

101. Structures
Protect Structural Integrity

102. Structures
Protect Structural Integrity
• Wood/less durable check dams vs. stone/more
durable check dams

103. Structures
Protect Structural Integrity & Prevent Flooding
• Culverts

104. Structures
Protect Structural Integrity & Prevent Flooding
• Culvert

105. Structures
Dos and Don’ts
Do’s
• Do remove sediment, debris & trash from inlet &
outlet structures such as curb cuts, rip rap, sumps
& grates.
• Do control and handle the removed sediment so it
won’t get back into the storm system.
• Do prevent excessive ponding by inspecting
underdrains.
• Do prevent flooding by clearing outlets of
obstructions.
• Do protect the integrity of structures such as
curbs, & walls.
• Do inspect less durable materials more often.

106. Structures
Dos and Don’ts
• Do inspect culverts to look for UV degradation,
cross-section shape changes that may cause
flooding, and corrosion.

107. Erosion Prevention
• Erosion prevention is any practice that protects
the soil surface and prevents the soil particles from
being detached by rainfall or wind.

108. Erosion Prevention
Cover Soils with Fabrics

109. Soil Quality Protection
Limit Compaction

110. Sediment (aka Source) Control
• “Sediment Control is any practice that traps the soil particles
after they have been detached and moved by wind or
water”…

111. Sediment (aka Source) Control
• …to prevent this!
Photo excerpted from “ODEQ Erosion and Sediment Control
Manual”, DEQ, Apr 2005

112. Sediment Control for Sheet Flow
Compost Socks

113. Sediment Control for Sheet Flow
Wattles (are your friends!)

114. Sediment Control for Concentrated Flows
Inlet Filters

115. Sediment Control for Concentrated Flows
Protecting Catch Basin Inlets

116. Erosion Prevention & Sediment Control
Dos and Don’ts
Do’s
• Do prevent erosion by keeping soil covered and
getting plants established.
• Do prevent erosion by staying out landscape
areas when possible. This also prevents soil
compaction, which slowly kills vegetation and
creates erosion long-term.
• Do control sediment when erosion cannot be
prevented by using wattles & filter sacks.

117. Spills

118. Clean up the spill
Do
• Determine what type of material has spilled
• Block stormwater inlets
• Use absorbent material to contain the spill
• Remove contaminated soil from facility
• Protective gear for workers

119. Clean up the spill
Don’t:
• Dispose of hazardous material in the garbage.
Must be taken to a hazardous waste facility.

120. Notify the appropriate authorities
Do
• Contact owner of the facility
Photo: morgueFile
• Contact local jurisdiction emergency response
• Contact OR Emergency Response 800-452-0311

121. Spills
Do
• Document the spill in the O&M report

122. Take Home Messages
• These recommendations are general guidelines
• Check with the local jurisdiction for specific
requirements
• Operations and Maintenance guidance document
being developed for our region
• For more information, contact:
candace@emswcd.org