Landcom Book 4 Maintenance - WSUD

Water Sensitive Urban Design
Item to be
Monitored
Purpose of Monitoring
Performance
Target
Schedule
Maintenance or
Investigation
Immediate
Action Required
Maintenance Action Required
The growth of weeds can impair a
wetlands performance by
- Changing flow paths through the
wetland
- Shading and out-competing plant
species that are important for water
treatment, or bed / bank stability.
Weeds can spread to downstream
environments, compromising
ecosystem health.
Weeds compromise the visual
amenity of the wetland.
Invasive plants in constructed
wetlands take the following forms:
Weeds
- Aquatic weeds (submerged,
emergent and floating)
No weeds present Weeds present Noxious or
environmental
weeds present
Emergent Plants (e.g. Typha):
schedule hand weed removal or
herbicide treatment.
Floating Plants (e.g. Salvinia) with
30% cover: removal with harvester
- Terrestrial weeds (e.g. within the
batter slopes)
No weeds present Weeds present Noxious or
environmental
weeds present
Hand removal or targeted herbicide
treatment (herbicide registered for
use around waterways).
Note: Herbicides should not be
routinely used to maintain edges
and banks. General spraying of
banks should not be undertaken
without follow up revegetation with
native species.
Algal
blooms
Algal blooms are easily detected:
the water colour becomes green,
the water clarity is poor and there
is an offensive odour. Although an
algal bloom can be a sign that the
wetland is working as intended (as
wetland organisms such as algae
remove nutrients from the water
column), algal blooms can be toxic
to aquatic organisms and humans.
Algal shading can kill macrophytes.
No algae apparent Algae visible Algal growth
prominent or
extensive
Schedule water quality testing:
e.g. cyanobacterial community
composition and cell count. When a
potentially toxic bloom is identified,
notify residents to avoid contact
with the water and continue
monitoring until the bloom subsides.
Notify the Environment Branch
Waterways Project Officer so the
lakes priority for management/
retrofit works can be reviewed.
Book 4 | MAINTENANCE 29