RAIN GARDEN
IR AZMAN ABU BAKAR
PERUNDING A ZMAN, OOI & RAO SDN BHD
CONTENTS
1. INTRODUCTION
2. PRINCIPLES
3. APPLICATION
4. BENEFITS
5. DESIGN CONSIDERATION
6. CONSTRUCTION METHOD
7. MAINTENANCE
8. RAIN GARDEN ILUSTRATION
1. INTRODUCTION
Bioretention basins (Rain Garden) : vegetated land depressions designed to detain
and treat stormwater runoff.
Treatment process : same as bioretention swales; the runoff is filtered through
densely planted surface vegetation and then percolated through a prescribed filter
media (soil layer).
Unlike bioretention swales, they do not convey stormwater runoff.
1. INTRODUCTION
Elements of a stormwater chain and how they can be integrated into typical residential and public or
commercial landscapes.
1. INTRODUCTION
1. INTRODUCTION
2. PRINCIPLES
Similar to bioretention swales - impurities are removed through fine filtration,
adsorption and some biological uptake (by plants, bacteria etc).
Typical section of a bioretention basin
2. PRINCIPLES
General principles of a biorentation facility. These typically consist of shallow
depressions of different shapes and dimension that drain surface water runoff-
and encourage its infiltration into the soil. Where the natural soils is
impervious, an engineered sandy or gritty soil may be substituted.
SOURCES : COFFMAN AND WINOGRADOFF, 2002
2. PRINCIPLES
2. PRINCIPLES
General principles of a biorentation facility. These typically consist of shallow
depressions of different shapes and dimension that drain surface water runoff-
and encourage its infiltration into the soil. Where the natural soils is
impervious, an engineered sandy or gritty soil may be substituted.
SOURCES : COFFMAN AND WINOGRADOFF, 2002
2. PRINCIPLES
CONTROL
STORMWATER HOW DOES BIORENTATION WORKS ??
QUALITY
Schematic diagram and design strategy of the rain
garden
BIORENTATION
WORKS
CONTROL
STORMWATER
QUANTITY
2. PRINCIPLES
HOW DOES BIORENTATION WORKS ??
Interception
CONTROL
Transpiration STORMWATER Infiltration
QUANTITY
Evaporation
2. PRINCIPLES
HOW DOES BIORENTATION WORKS ??
Settling
Degradation &
Filtration
decomposition
CONTROL
STORMWATER
QUALITY
Adsorption Assimilation
3. APPLICATION
act as ‘standalone’ soil
filtration systems within
parklands, green buffers,
carparks or along roadway
corridors.
various scales and
shapes ; in planter
boxes, in retarding
basins or integrated
with streetscapes
3. APPLICATION
Residential and commercial stormwater chains. The two diagrams show how linked sequences
of features can capture rainfall and release it back into the landscape at the residential (top)
and commercial (bottom) scales
3. APPLICATION
Residential On-lot
Rain Garden (Prince George’s County) Simple design that incorporates a planting
bed in the low portion of the site
3. APPLICATION
Tree and Shrub Pits
Stormwater management technique that intercepts runoff and provides shallow
ponding in a dished mulched area around the tree or shrub.
Extend the mulched area to the tree dripline
3. APPLICATION
Roads and highways
3. APPLICATION
Parking Lot Island Bioretention
3. APPLICATION
Curbless (Curb cuts) Parking Lot Perimeter Bioretention
The Rain Garden is located adjacent to a parking area with no curb or curb cuts ,
allowing stormwater to sheet flow over the parking lot directly into the Rain
Garden. Shallow grades should direct runoff at reasonable velocities; this design
can be used in conjunction with depression storage for stormwater quantity control.
3. APPLICATION
Curbed Parking Lot Perimeter Bioretention
3. APPLICATION
Roof leader connection from adjacent building
3. APPLICATION
Bioretention basins at Lower Seletar Reservoir (left) and Balam Estate (right)
3. APPLICATION
July 27, 2006
Demonstration Rain Garden. North Kingstown
Town Hall, June 2005.
January 30, 2006
3. APPLICATION
Rain Gardens are designed to temporarily pool and soak up runoff water.
4. BENEFITS
Reduce flow
velocities
Water is filtered and Encourage
cleansed naturally habitat creation
without the use of and promote
any chemicals biodiversity
BENEFITS
Easy set up, minimal
maintenance, Beautify surrounding
inexpensive landscape
and versatile
4. BENEFITS
RAIN GARDENS ARE GOOD FOR WILDLIFE AND BIODIVERSITY
Rain garden
ecotone,
Amstelveen,
the
Netherlands.
Wetlands that
exploit a
diverse range
of plants
create the
greatest
Making water visible has additional side-effects:
potential
its provides an opportunity for lunsh naturalistic
opportunities
planting and a haven for wildlife
for wildlife
4. BENEFITS
RAIN GARDENS PROVIDE VISUAL AND SENSORY PLEASURE
&
RAIN GARDENS ARE GOOD FOR PLAY
Children are fascinated by
water in all its forms
Even crossing a broadwalk over wet ground is exciting. Bringing
water into a landscape allows for interaction in a way that no
other element promotes.
5. DESIGN CONSIDERATION
6. CONSTRUCTION METHOD
Install temporary sediment control BMPs as shown on the plans.
Complete site grading. If applicable, construct curb cuts or other inflow entrance but provide
protection so that drainage is prohibited from entering construction area.
Stabilize grading within the limit of disturbance except within the Rain Garden area. Rain
garden bed areas may be used as temporary sediment traps provided that the proposed
finish elevation of the bed is 12 inches lower than the bottom elevation of the sediment
trap.
Excavate Rain Garden to proposed invert depth and scarify the existing soil surface . Do not
compact in-situ soils. Backfill Rain Garden with amended soil as shown on plans and
specifications. Overfilling is recommended to account for settlement. Light hand tamping is
acceptable if necessary.
Presoak the planting soil prior to planting vegetation to aid in settlement. Complete final
grading to achieve proposed design elevations, leaving space for upper layer of compost, mulch
or topsoil as specified on plans.
Plant vegetation according to planting plan.
Mulch and install erosion protection at surface flow entrance where necessary
7. MAINTENANCE
Maintenance of
depression profile to
keep a clear flow to
and through the
bioretention basin.
Regular care, such Routine
as irrigation, inspection of
weeding, mowing, inlet, outlet and
pruning and overflow points
pestcontrol, are to clear any
necessary blockage
Maintenance
Maintaining
Routine removal of
healthy
litter, debris and
vegetation
sediments
growth
Raking of the
bioretention basin
surface and flushing of
the subsoil perforated
pipes if there is
evidence of clogging
8. RAIN GARDEN ILUSTRATION
BEFORE
8. RAIN GARDEN ILUSTRATION
AFTER
