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· Hunts Creek catchment,
North Parramatta
· UBD Map 191 D9
· Kiosk, toilets, shelters
· Problems with
domestic ducks interbreeding with native species and weed
invasion
· 500 m walking
loop
· Vision:
Swimmable by 2005
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Site Information
Lake Parramatta is a 10 hectare reserve. The catchment area for
the Lake is bounded by North Rocks Rd, Pennant Hills Rd and Hunts
Creek. The dam wall is of arch sandstone construction, engineered
so that the weight of the water keeps keystones in place. It was
constructed in 1856 to provide a supply of freshwater for Parramatta.
When Parramatta was connected to the metropolitan water supply in
1890, the Lake became a popular swimming spot. Declining water quality
in the Lake has prevented its use for swimming since the 1960’s.
Today the Lake and surrounding bushland are used for recreational
activities such as picnics, walking and canoeing. There is a 500m
walking loop around the long ridge top.
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Domestic ducks threaten biodiversity and Pollute the lake
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Lake Parramatta dam wall
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Environmental Management
Water quality in the lake is threatened by stormwater pollution
(oil, leaves, litter, sediment, nutrients, chemicals and pesticides)
sewerage overflows and leaks and contaminated sediment. Recurring
Salvinia blooms affect biodiversity and tourism. The dumping
of domestic ducks at the Lake has resulted in problems with faecal
coliform contamination of the water. These domestic ducks also damage
natural biodiversity by interbreeding with native species.
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Sandstone outcrops and blue gum forests
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Salvinia bloom on Lake Parramatta
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The “Swim 2005” program is being implemented by the Trust
and Parramatta City Council to educate the community about their
impacts on water quality. The Lake Parramatta Water Quality Management
Plan has been developed by the Trust and identifies the mechanisms
for making the Lake swimmable again.
Geologically, the Lake is located on the margins of shale and sandstone
formations, with a resulting variation in vegetation communities.
Vegetation communities present at the site include sandstone blue-gum
forests, iron bark, Cumberland Plain Woodland vegetation communities
and some coastal species such as Banksia serrata.
Parramatta Council has a bush regeneration program underway in
weed-affected areas of the reserve. Residents along North Rocks
Road have established a community group that is regenerating bushland
that backs onto the Lake at the rear of their homes.
Site Walk
1. Start the walk at the Dam wall. Note the sandstone outcrops,
native bushland. What birds can you hear/see? What other sounds
can you hear? Note the close proximity of the main road. Can you
see any other animals such as lizards? How might this area have
looked before the dam wall construction? Why would this site have
been chosen for the construction of the lake? Give at least two
reasons.
2. Walk to the constructed wetlands. This was once the main area
that people used for swimming. Why would the wetlands have been
constructed here? Note the stormwater pipe that flows into the edge
of the wetlands. How does a wetland work? What contaminants may
be in the water? Name two and their possible origins. Note the sediment
build up near stormwater entrance. How could this area be improved
both in terms of its effectiveness and aesthetic value?
3. Walk along the lake away from the dam wall. Note the number
of introduced ducks and their droppings. What impact could these
ducks have on the local biodiversity? How could the duck droppings
affect the water quality in the lake? Note the ‘No Swimming’
sign near the wetlands. This site could potentially be tested for
faecal coliform bacteria.
4. Continue walking along the lake. Toilets are available near
the BBQ area. Note the native regeneration work that has been carried
out here. How does it look compared to the grassed area where the
ducks are? Count the number of species present here and compare
to the grassed area in front of the shop.
5. Walk onto the pedestrian access track. Looking over the lake,
how might this area have looked prior to the dam? This is Sydney
Sandstone Gully Forest. Compare the grass and weed species on left
of the track to native vegetation on the left. Note the invasive
nature of the weed species.
6. Follow the marker on the left of the track to walk closer to
the lake. Caution as this area may be slippery. Ensure students
stay to the track so as not to adversely effect the vegetation.
Students may wish to listen for birds/lizards/snakes and note the
numbers as they walk.
7. Track opens out to rock ledges. Compare the view toward the
car park to that upstream.
8. Continuing on the track, a small creek enters from the right.
Where would this water have come from? What might it have brought
with it? Name two possible pollutants. Note weeds such as lantana
that line the creek. Why would the weeds be here?
9. As track continues, note the change in the understorey from
grasses to small trees and shrubs. Why would this change occur?
Note the change in smell. What does that make you think of? Does
the vegetation look healthier here? Why?
10. Second tributary. Note the difference in the vegetation and
health of the creek. Present is moss, ferns, birdcalls, clean water.
Why would this creek be different? Could this have been hoe the
creek would have been before the dam?
11. As track opens out, not the change in ground from sandstone
to shale.
12. Turn around and on the way back take the high track. Note the
difference in areas such as vegetation, temperature, smell. What
could be done to improve this area? What is already being done?
What could you do?
Site Activities
- Catchment walk
- Water quality testing
- Habitat assessment
- Transects, quadrats
- Mapping
- Weed identification
- Bush regeneration
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