·         Greystanes Creek, Oklahoma Ave, Girraween

·         UBD Map 189 H12

·         No mow zones Þ regeneration of native grasses

·         Coastal Riverflat Forest (endangered)

·         School tree planting days can be organised with advance notice

Site Information

The Trust and Council have undertaken significant regeneration work along Greystanes Creek in this area. The open space at John Silverthorne Park, including the levy banks and nearby Fox Hills golf course, act as a flood detention basin. The park contains an important island of Coastal Riverflat Forest (an endangered ecological community) with cabbage gums and casuarinas. In 1996 mowing of the open space around this forest community was stopped. Since then there has been significant natural regeneration of the area by native grasses and saltbush. Local indigenous species such as melaleuca and native grasses have also been planted in the perimeter of the stand. A local bush regeneration group has worked very hard on rehabilitating this area. Ground parrots (endangered species) are also part of this important ecological community. There are heavy clay soils at the site that form deep cracks during dry spells.

Wetlands have been constructed within the creek line and are now colonised with sedges and rushes such as Juncus and Phragmites. Large rocks were placed within the creek line to dissipate energy during peak flow. Regeneration work has been undertaken along the creek line and around the edges of the natural regeneration areas. The effort has been strongly supported by the local community, with an active bushcare group continuing to work on the site.

A heavy industrial area at Girraween is located upstream from the site. A number of illegal discharges have been identified from industry in this area. On the corner of the Great Western Highway and Toongabbie Road there is a sediment dump-site. The riparian zone along this section of the creek has been removed and the creek banks are regularly sprayed with pesticides to control weed growth.

Site Activities

o        Measure tree height and growth rates from year to year over successive visits to site

o        Spot birds – keep a list of birds sited over successive visits to site

o        Spot flood levels from litter zones in trees

o        Weed identification

o        Plant identification

o        Catchment walk

o        Water quality monitoring

o        Habitat assessment

o        Water bugs

o        Endangered ecological communities

o        Transects, quadrats

o        Mapping

o        Investigate landuse upstream of site – identify potential pollution threats to Toongabbie Creek

o        Compare vegetation levels with aerial photos from 1999 (pre-revegetation work)

Site Walk

1.      Begin at southern end of Oklahoma Avenue and follow path to the south, towards the golf course.

Note the sewer breather pipe and manholes. These are potential sewer surcharge points. Why does the sewer system need surcharge points?

2.      Cross the first bridge. Water test sites are located upstream near the drain outlet at edge of golf course. Access is reasonable for small number of students to collect water samples for testing.

3.      Cross second bridge and turn right to follow the creek. Cross mown area. Note weed infestations, identify weeds.

4.      Continue across the small creek line. Note the regeneration occurring in the unmown areas. Identify the main plant species present.

5.      Turn right and follow track.

Walk through stand of Casuarina trees and observe the creek. Compare with creek at the beginning of the walk.

6.      Continue along track. At the junction note the older regeneration site that includes Coastal Riverflat Forest (an endangered ecological community). What is the main difference with the younger regeneration areas? Compare with the area immediately across the track at the junction.

7.      Turn right at the junction and follow track to Memphis Crescent. Turn right onto cement path. Follow to bridge. Compare the creek with earlier observations. Macro invertebrate testing could be performed downstream of the bridge where access is easier.

8.      Turn right across the bridge and continue back to Oklahoma Avenue.