1. Ecological restoration project 2011-2013
In 2011, following careful planning by our BMCC Bushcare Officer, the bushcare group commenced a small ecological restoration project on the former Lawson golf course site. The prime objective was to restore a former natural woodland site that many decades ago had been converted to a mowed grass area. Another important objective was to widen the riparian corridor of Lawson Creek and adjoining swamps to restore and enhance their ecological functioning. The project area extended over approximately 2000 square metres.
The Society for Ecological Restoration Australasia maintains a set of “National Standards” for the practice of ecological restoration, and the Lawson project met these standards.
- The project aspired to the recovery of a very high (substantial to full) level of ecological functioning on the site.
a. To restore ecological functioning associated with indigenous bushland (E. piperita – Angophora costata) to a regularly mowed strip of grass. The project envisioned the restoration of appropriate vegetation layers: tree canopy, shrubs, ground layers. The original bushland had been totally destroyed approximately eighty years ago. Restoration of a high level of fauna habitat was anticipated, including, in time, avifauna nesting habitat.
b. To provide a further layer of environmental protection to Lawson Creek and adjacent swamps by restoring ecological function to the creek’s riparian corridor and boost terrestrial indigenous animal habitat.
c. To restore further ecological function to Lawson Creek by enhancing its water quality and aquatic animal habitat.
The project also enhanced ecosystem services on the site, in the form of water quality and amenity. The creek borders popular walking tracks and is part of the Hawkesbury-Nepean catchment.
- Targets, goals and objectives were set.
Target: restoration of a totally degraded area to E. piperita – Angophora costata woodland status.
Goals: maintain and renew planting regime over three years; maintain and renew fencing and interpretive signage over three years to protect natural regeneration; ongoing monitoring for shrubby weeds reducing to minimum of six monthly monitoring for weeds and vandalism.
Objectives: obtain administrative approval for project and liaise with other stakeholders; two sessions of fencing to delineate non-mowing area; design, obtain and erect interpretive signage; commence replanting of shrub layer on monthly basis; facilitate and encourage natural regeneration; remove woody weeds (minimal occurrence) as encountered.
- There was extensive and ongoing community involvement, both in the form of the local volunteer bushcare group, a visiting volunteer community group, local resident interest, consultation with Blue Mountains City Council (land managers) staff and incorporation of the project into the Blue Mountains City Council 2019 Masterplan for the area. Signage explaining the project advised users of the site.
- Contemporary, validated restoration techniques were used: replanting with indigenous flora sourced from a specialist native nursery, and natural regeneration. The relevant administrative authorities were consulted, approvals obtained, and other land-users were informed about the project.
- The level of intervention was reasonably appropriate. The original Open-forest on the site had been totally destroyed for eighty years or more, so protective fencing, replanting and facilitation of natural regeneration were suitable responses. Indigenous flora species, grown from locally sourced seed (local provenance), were obtained from a Blue Mountains’ specialist native plant nursery. Natural regeneration of indigenous flora via dispersed seed from the adjoining Open-forest flourished. Tree seed for nursery propagation is hard to collect due to tree height, and natural regeneration helps to overcome this problem.With hindsight, less planting could have been used, as natural regeneration was very strong, particularly of Eucalyptus spp.
- The adjacent natural woodland (E. piperita – Angophora costata woodland) was utilised as a reference ecosystem, or restoration model.
(See: Society for Ecological Restoration Australasia, National Standards for the Practice of Ecological Restoration in Australia 2nd edition 2018 http://seraustralasia.com/standards/National%20Restoration%20Standards%202nd%20Edition.pdf )
The project is on track to meeting its ecological objectives: little maintenance is required, the re-established vegetation is thriving, and there appears to be good diversity of indigenous flora species present, including trees. It is anticipated that existing weedy grasses may well be eradicated by natural mulching and and shading out in the future. Many thanks to our Bushcare Officer for initiating this project.
Following good rains in the summer of 2019-2020, Eucalyptus spp. have grown strongly, and are now averaging 15 metres in height. E. piperita and E. sieberi are prominent. Hakea spp., Leptospermum spp. Tea-tree and Kunzea spp. Tick Bush are also doing very well.
2. GWH upgrade 2009
As part of its redevelopment of the Great Western Highway at Lawson, the then RTA (now RMS) had to manage the stormwater flows of the new four lane road, and proposed the construction of a large stormwater detention basin south of the GWH, near the end of Ferris Lane and adjacent to Lawson Creek and swamp. From the outset of this project the Bushcare Group was registered as a stakeholder, and was extensively involved in negotiations with the RTA Lawson project management team. The bushcare group’s objective was to mitigate the potential adverse environmental effects of this stormwater work on Lawson Creek and adjacent swamps.
Detention basin construction by RTA adjacent to Lawson creek swamp Nov 2009 Photo: P Ardill
Detention basin construction by RTA July 2009 Photo: P Ardill
A stormwater detention basin with a discharge channel to Lawson Creek were constructed in 2009. Major issues were the route of the pipeline from the GWH (minimising bushland impacts), the size of the detention basin (to adequately hold stormawater), the rate of discharge flow from the detention basin into Lawson Creek (not too fast or strong), the route of the channel into Lawson Creek (avoiding swamps) and the possibility of building holding ponds as part of the stormwater dispersal system, as an alternative to a channel through the swamp.
The bushland and swamps adjacent to the detention basin channel area have, to a certain extent, regenerated well. This was largely due to the planting of Tea-tree (Leptospermum polygalifolium) by Bushcare Group members in 2011, and ongoing weeding by the group. However, the channel is infested with Juncus microcephalus, and in the future the seed from this weed will continue to flow into Lawson Creek. Many of the plant species installed by the RTA were not regional species, and so were highly inappropriate; they have been removed.
Detention basin outflow channel cut through swamp July 2009 Photo: P Ardill
Same detention basin channel area, now well vegetated, Jan 2017 Photo: P.Ardill
3. Waratah Street 2010 & 2016
The unformed section of Waratah Street between Honour Avenue and New Street borders the upper reaches of Lawson Creek and its tributaries, and weed growth here is prolific. The area received bush regeneration and stream management attention in 2010. Noticeable weed issues here are Privet, Scotch Broom, Japanese Honeysuckle and Blackberry.
In July 2016 the bushcare group removed extensive amounts of Privet, Scotch Broom, Cootamundra Wattle and Tree Lucerne from the Waratah Street site (eastern section). These weeds can easily form dense thickets and encroach on and compromise the original bushland around the upper catchment of Lawson Creek. We try to maintain a weed free buffer zone around the good bush, but there still are dense patches of weed (Privet, Blackberry, Japanese Honeysuckle) in this area.
Diversity and beauty, intact Waratah Street bushland, July 2016 Photo: P.Ardill