Landcom Book 4 Maintenance - WSUD

Water Sensitive Urban Design
6.1.3 Stage 3: Operational establishment (civil and/or landscaping)
Stage 3 involves reconnecting the functional elements of the WSUD element to meet
design specifications. In general, this involves decommissioning erosion and sediment
control protection devices and replanting of landscape areas. Specific tasks within stage 3
as they relate the WSUD elements addressed in the Operations and Maintenance booklet
are:
Bioretention basin
Desilt basin if converted
to a temporary sediment
basin.
Remove measures
protecting filter media,
for example bunds, filter
cloth, topsoil and turf.
Flush out under-drainage
using potable (mains)
water
Flatten filter media
surface to within given
tolerance (additional
media may be required
to fill in over-excavated
areas)
Mulch filter media,
allowing for planting
holes
Dig holes for planting
Plant nominated species
Maintain landscaping
to ensure healthy plant
establishment
Constructed wetland
Remove accumulated sediment
and gross pollutants from inlet
zone (and macrophyte zone if
the wetland has been used as a
sedimentation basin during stage
2)
Assess the condition of the
impervious liner and hydraulic
structures (if the wetland has
been operated as a temporary
sediment basin in stage 2) and
amend accordingly
Install topsoil in basin to a depth
of 300 mm on batters and 500
mm below the normal water
level (this will be required for the
macrophyte zone only if zone
used as a sediment basin during
stage 2)
Remove disconnection between
inlet and macrophyte zone (only if
macrophyte plantings have been
established during stage 2)*
Landscape macrophyte zone if
zone not yet established**
Landscape inlet zone according
to the design specifications**
Sedimentation basin /
pond
Desilt basin
Remove sterile grass from basin
and establish marsh zone and
embankment planting as per
the design specifications
Install topsoil to a depth of 300
mm on batters and 500 mm
below the normal water level
Landscape basin as per the
planting specifications***
NOTE:
* If the wetland has been used as a temporary sedimentation basin during stage 2, establish macrophyte
plantings prior to bringing the macrophyte zone online. Specific requirements for plant establishment in the
macrophyte zone of a constructed wetland are detailed in the Water by Design documentation.
** Water levels will need to be manipulated during landscape establishment
*** Water level manipulation is not required for ponds. The plants specified for the base of ponds will be suitable
for an environment starved of oxygen. Typically plant establishment in ponds is through anchoring the plants /
seedlings to the pond base with rocks.
This task is required regardless of what sediment control measures are instigated as part of stage 2.
Specific plant establishment requirements including fertiliser application and
recommended watering schedule (including frequency of watering for terrestrial and
marsh plantings, and the requirements for water level manipulation in constructed wetlands
and ponds) are not detailed in this booklet. The reader is directed to the Water by Design
(2009) documentation for further information.
44 Book 4 | MAINTENANCE