·         William Lawson Park, Prospect

·         UBD Map 188 P9

·         Impacting on native grasses

·         Constructed wetlands

·         Bird life ++

·         Toilets available (arrange key from Blacktown Council)

·         Tree planting possible with advance notice

Site Information

The Lancelot Street Wetland was constructed by Blacktown Council in 1999, with assistance from the UPRCT and the NSW Government Stormwater Trust. These wetlands are particularly interesting because they involved the conversion of a mown grass flood retarding basin into a multi purpose environmental and recreational facility. The wetland now supports a diverse range of animals, including tortoises and birds. To combat mosquito breeding, water in the wetlands is circulated to break surface tension and prevent breeding. There is a gross pollutant trap (GPT – see Figure 2) located at the Blacktown Creek inlet to the wetlands. A further four GPT’s of varying designs are located in the wetland inflow points. A one way valve has been installed to prevent backflow of water up pipes when the wetlands are flooded. A low flow channel runs underground beneath the wetlands. Swales have been installed for flood flows. They reduce runoff velocity and have the added benefit of removing coarse particulates.

Significant numbers of native water birds have been attracted to the wetland since it was constructed. The large size of the bird population is retarding the establishment of native grasses and reeds, as they compete for food and trample to plant seedlings. Domestic ducks at the wetland have also become a problem. Domestic ducks eat vegetation around edges and along with native ducks erode the shallow margins of the wetland. Purple Swamp hens can be seen running through reeds and have built nests amongst the reeds.

Animals and birds that can be found at the wetlands include the Purple Swamp hen, native ducks, sparrows, eastern long necked turtles and eels.

Stormwater Treatment Devices

Stormwater treatment devices reduce the pollution load entering a waterway by trapping gross pollutants such as litter, leaves and sediment (eg. Gross Pollutant Trap). They can also slow the flow of a waterway and retain excess nutrients (eg. Constructed Wetlands).

Figure 1: Constructed wetland (Managing Urban Stormwater NSW EPA 1997)

Constructed wetlands are a shallow water body with a large proportion of its water surface covered by macrophytes. The wetland slows the flow of a waterway and traps sediment. Visually attractive, they provide habitats and recreational areas. However, unmanaged they can create a habitat for mosquitos, noxious weeds and nuisance odours from stagnating materials.

A gross pollutant trap (GPT) will catch litter and coarse sediments before they can enter a wetland, pond or other stormwater treatment device. The GPT also concentrates litter at a single location ready for easy removal.

Figure 2: Gross Pollutant Trap (Managing Urban Stormwater NSW EPA 1997)

Site Activities

o        Catchment walk

o        Opportunity for water sampling (slippery edges)

o        Tree planting (arrange with UPRCT beforehand)

o        Habitat assessment

o        Transects, quadrats

o        Mapping

o        Flood mitigation

o        Problem of domestic ducks eating revegetation plants –design a management strategy

o        Observe adaptations eg swamp hens can run through reeds and build nests

o        Turbidity testing comparison of inflow/ponds/outflow

o        Observe impacts of vandalism – local not used to interacting with environment

Site Walk

This site has constructed paths with site signs describing many aspects of the site.

1.      Begin at the main sign at the Lancelot Street entrance to the wetlands.

Answer the following questions:

What area does the wetland drain?

What are the goals of the wetland?

What are the components of the wetland?

Draw cross-section diagrams to show the construction of the wetlands.

2.      Follow the main path to the left (clockwise) going outside the spillway.

Are there any signs of pollution in the spillway?

Note the reeds in various parts of the wetland. What purpose do they perform?

3.      Continue along the path taking the right fork to stay by the edge of the wetland. Stop at the sign describing the plant species.

What plant species are in the wetland? Can you identify any of these within the wetland?

Why are wetlands important?

4.      Follow path across the floodway.

Observe the quality of the water entering the wetlands.

What is the purpose of the rocks laid across the entering water?

5.      Continue in a clockwise direction along path back to Lancelot Street to the sign describing bird species.

What native bird species can be found in the wetland?

What non-native bird species can you see?

What problems may these non-native species cause for the native species?

6.      Easy access for collection of water samples can be found at this point adjacent to Lancelot Street.

Note the areas of native revegetation around the wetland.

Why is it important to plant and maintain areas of native plant species?

                                       Information board at Lancelot St wetlands