From June 2008 to June 2011, ecological restoration work was conducted by Port Authority of NSW in association with the expansion of the port at Port Botany, Sydney, NSW. The purpose was to expand and rehabilitate Penrhyn Estuary.

Dragonfly Environmental were responsible for carrying out the world’s largest ever Saltmarsh re-creation. The Saltmarsh works at Penrhyn Estuary involved 2.4 hectares being densely planted with Saltmarsh species. In addition to this 3000m2 of Saltmarsh was translocated within Penrhyn Estuary. The key driver for the Saltmarsh design and plant selection was the requirement for the project to provide habitat for migratory wading birds.

To our knowledge this is the largest recorded Saltmarsh construction project recorded to date, planting over 230,000 Saltmarsh plants, in which Dragonfly Environmental planted that incredible amount of plants in just 14 days. That is roughly 16,429 plants a day.

The main Saltmarsh species occurring in Penrhyn Estuary are Suaeda australis, Sarcocrnia quinqueflora, Sporobulus virginicus and Juncus kraussii. The Saltmarsh species mix planted in the Estuary will increase the diversity of the community by introducing species considered suitable and that currently occur in other Saltmarsh sites in Botany Bay.

Australia’s saltmarshes are ecologically important ecosystems that link the land and sea, providing productive habitats for a range of species, including migratory shorebirds. Unfortunately, Saltmarsh is an endangered ecological community under the NSW Threatened Species Conservation Act 1995.

With such a successful project, habitat management and maintenance of the Penrhyn Estuary is key in protecting the shorebird habitat. Dragonfly Environmental is pleased to continue working with Port Authority of NSW at Botany Bay to ensure that shorebird habitat is maintained.

Viewing platforms for the public were created to give visual access to the estuary. Its goal is to minimise the disturbance to the shorebirds and protect the Saltmarsh and seagrass. Dragonfly makes sure that the fencing that keeps out the public and feral animals are maintained and repaired if damaged. Along the public walkways, vegetation is controlled and any weeds or rubbish removed.

Mangroves are seen as detrimental to shorebird habitat as they colonise shorebird feeding and roosting habitat and compete with Saltmarsh for space. Migratory Bird Islands are maintained by reducing the height of any vegetation found growing on these islands, any objects or debris found are also removed.

Saltmarsh plays a key role in stabilising the banks of estuaries, filtering surface runoff, reducing nutrients and providing habitat for fauna. Erosion of Saltmarsh habitat results in loss of planted area, so it is important to monitor any plant loss and the health of the plants. Dragonfly replants any areas that have poor plant establishment or have been disturbed by flood or storm events.

The key objectives of the Penrhyn Estuary habitat enhancement were to expand the existing shorebird habitat, to continue to attract migratory shorebirds and potentially attract more shorebirds. Also to establish and maintain 2 Hectares of restored Saltmarsh within the site.

Dragonfly Environmental identified key issues for the waterway, made recommendations to improve waterway health and native vegetation condition. In addition, actions were prioritised and a cost estimate provided.

Dragonfly Environmental are currently working on a contract to restore saltmarsh and riparian vegetation representing three different Endangered Ecological Communities within Lane Cove National Park.

Dragonfly Environmental carried out wetland assessment, vegetation mapping including mapping of the Endangered Ecological Community Eastern Suburbs Banksia Scrub community and stakeholder consultation and engagement and the writing of the Plans of Management and Plans of Operation.

Method & Technic:

• Aquatic Weed Treatment
• Bush Regeneration
• Revegetation

Project Outcomes:

Dragonfly Environmental was engaged to deliver long-term ecological restoration and stormwater management improvements at Coolibah Reserve and along Bardwell Creek and Bardwell Wetland. The project spans over 3.7 hectares and forms the final section of the Bardwell Creek Biodiversity Corridor, connecting to the broader Wolli Creek system.

Prior to 2020, our team undertook significant revegetation efforts along Bardwell Creek and Wetland, including the installation of 27,500 native plants—400 of which were advanced 8” aquatic species. These foundational works contributed to the establishment of riparian vegetation and set the stage for long-term ecological recovery and water quality improvement.

By 2023, Coolibah Reserve supported a mosaic of regenerating native bushland, remnant canopy trees, stormwater filtration zones, and revegetated riparian corridors. These areas collectively support two Endangered Ecological Communities (EECs): Swamp Oak Floodplain Forest and Swamp Sclerophyll Forest.

During the most recent contract period, our team carried out both primary and maintenance works across all five zones of the reserve. While routine sweeps targeted common weed incursions, primary works focused on degraded pockets, gradually improving site resilience while enhancing biodiversity and visual amenity. Zones 3 and 5 saw particularly notable improvements, with successful expansion of revegetated areas helping stabilize the creek line and prevent further erosion.

Weed control efforts significantly reduced the presence of high-priority species such as Tradescantia fluminensis and Anredera cordifolia, while regular management helped suppress annual herbaceous weeds. Despite these gains, areas impacted by nutrient-rich stormwater runoff remain a challenge and will benefit from ongoing restoration and support.

Revegetation works have played a key role in expanding the ecological corridor and improving the site’s function as a filter for urban runoff. Future work is recommended to continue in alignment with the current strategy, with increased planting and mulching to support newly established zones, improve visual presentation, and suppress invasive grasses.

This project stands as a strong example of how targeted revegetation, weed control, and habitat corridor restoration can meaningfully improve biodiversity, ecological function, and landscape aesthetics in urban environments.

Before	After

Before	After