Stage 4 of the project involves upgrading the flow capacity of Upper Brown Hill Creek and Glen Osmond Creek to prevent ‘break-outs’ and flooding of private property. Key hot spots are being targeted to align with grant funding opportunities.
4A Anzac Highway to Third Avenue, Everard Park
Located between Anzac Highway at the downstream end and Third Avenue at the upstream end, these works were expedited to take advantage of site access that would be significantly restricted following completion of an adjoining high density residential development. The project involved replacement of a 140 metre length of open concrete channel with an increased capacity underground culvert.
Subsequent to installation of the culvert, the City of Unley delivered ground level improvements to extend Wilberforce Walk to Anzac Highway, with a shared use path for pedestrians and cyclists traversing the culvert.
Culvert construction was completed in August 2020, at which point the site was handed over to City of Unley for delivery of shared use path improvements.
View the Everard Park information brochure.
4B Third Avenue to Leah Street, Forestville
Brown Hill Creek runs alongside Wilberforce Walk, an established shared use path network recently upgraded by City of Unley, and in its current form the channel and road crossings are of insufficient capacity to accommodate major flows.
The condition of the existing watercourse has been significantly altered from its natural condition, with a concrete low flow channel and steep banks that are prone to erosion. Where Brown Hill Creek passes beneath Second Avenue there are currently no footpaths, resulting pedestrian safety concerns.
An arborist assessment revealed a diverse range of tree species, both native and introduced, including trees that are located within the watercourse corridor that will require removal and a Significant Red Gum that needs to be protected and retained. An ecological assessment identified a predominance of invasive weeds – 53 species of weeds were identified, including declared and environmental weeds.
There is an urgent need to upgrade this section of Brown Hill Creek to improve flow capacity and public safety, while enhancing the tree canopy and understory with native species that provide habitat and biodiversity outcomes.
Description of Proposed Works
The delivery approach seeks to achieve the required flow capacity while ensuring protection of the Significant Red Gum and maximising opportunities for planting new large native trees to enhance the tree canopy along Wilberforce Walk.
For the channel bank adjacent to the Significant Red Gum a stacked rock wall treatment will be constructed to ensure that the structural root zone of the tree is not impacted by the works. For the other sections of channel bank, a vertical concrete block wall will be used to minimise the width of Wilberforce Walk that is required for the open channel and to maximise the area between the channel and shared path for the establishment of new trees and plantings.
While some trees are required to be removed for the upgrades, most of these are weed and exotic species, and on completion of the channel works an extensive revegetation program will be undertaken to plant new trees, shrubs and groundcovers along the creek corridor but outside of the main channel.
A new 1,200mm high ‘open style’ safety fence will be installed along the top of the channel wall in Wilberforce Walk and the existing cobble base of Brown Hill Creek will be retained and replenished with new stones.
The new culvert crossings at First Avenue and Second Avenue will include the relocation of some existing utility services and new footpaths on both sides of the roads.
Once the works are completed this upgraded section of watercourse will convey the 1% Annual Exceedance Probability (or 1-in-100 year) design flow as defined in the Brown Hill Keswick Creek Catchment Stormwater Management Plan.
Delivery of these works will mark completion of the Area 1 upgrades of Upper Brown Hill Creek in Forestville.
4C Leah Street to Ethel Street, Forestville
Located between Leah Street at the downstream end and Ethel Street at the upstream end, the upgrades in this location involve raising the height of the existing channel walls by 600mm and remediating the floor and walls of the existing channel. The majority of the channel is located within Council owned drainage corridor, with a small portion extending through privately owned property. These works were completed late in 2024.
View the UBHC 1C Forestville Works Notification.
4D Forestville Reserve
The condition of the existing Brown Hill Creek watercourse through Forestville Reserve has been significantly altered from its natural condition. The concrete low flow channel and steep banks require restoration efforts to improve ecological health and biodiversity.
An arborist assessment revealed a diverse range of tree species, both native and introduced, including trees that are located within the main channel that will require removal and other mature trees along the watercourse corridor that can be retained.
An ecological assessment identified 23 weed species, including declared and environmental weeds, and 8 native species including Blackwood and River Red Gum, highlighting the importance of preserving the existing local flora.
The survey recorded 12 bird species, including the Red Wattlebird and Laughing Kookaburra, indicating the area’s ecological value and the need for habitat improvement.
There is a need to rehabilitate this section of Brown Hill Creek to improve the creek function, biodiversity, amenity and community interaction at the reserve.
Description of Proposed Works
The delivery approach seeks to achieve channel naturalisation and biodiversity outcomes with a focus on protection of significant trees, improved water quality and habitat for native species, and opportunities for increased amenity and community interaction.
New gabion walls will be constructed for the channel banks – the gabion baskets can be installed with limited disturbance to the existing channel banks and will be filled with sandstone quartzite stones to prevent erosion. The baskets are durable and flexible and will tolerate future ground movements.
On the western side of the channel, the new gabion walls will be constructed in a terraced configuration to maximise the opportunity for new plantings. The existing concrete base will be removed and replaced with cobble stones to promote roundwater replenishment.
The works will not impact the existing playspace and a new 1,200mm high ‘open style’ safety fence will be installed along the top of the gabion wall in Forestville Reserve. The existing pedestrian bridge to the Unley Swimming Centre will be replaced.
While some trees are required to be removed for the upgrades, most of these are weed and exotic species, and on completion of the channel works an extensive revegetation program will be undertaken to plant new trees, shrubs and roundcovers along the creek corridor.
Once the works are completed this rehabilitated section of watercourse will convey the 1% Annual Exceedance Probability (or 1-in-100 year) design flow, as defined in the Brown Hill Keswick Creek Catchment Stormwater Management Plan.
View the project fact sheet here.
4E DIT Diversion Culvert
A section of Brown Hill Creek in Forestville was diverted by the Department of Planning, Transport and Infrastructure (now the Department of Infrastructure and Transport) in 2013 as part of the Goodwood Junction Rail Upgrade Project.
The works, delivered in collaboration with and funded by the Brown Hill and Keswick Creeks Stormwater Board, involved diverting the creek into a new underground culvert constructed generally along the eastern side of the railway corridor from the southern side of Victoria Street to the northern side of the Glenelg Tramway. The culvert discharges into the existing Brown Hill Creek channel within Forestville Reserve.
4H Orphanage Park
The condition of the existing Brown Hill Creek watercourse through Orphanage Park is significantly degraded and the historical land use has led to disturbance and loss of native vegetation.
An arborist assessment identified 36 tree species, including both native and invasive types. An ecological assessment identified various bird species and mammal signs, indicating the presence of wildlife in the area. Five bird species were observed, including the Black-faced Cuckooshrike and Eastern Rosella, although hollow-bearing trees were not observed.
Sedimentation and bank erosion are currently impacting riparian vegetation, and the assessment also identified a predominance of invasive weeds – 33 species of weeds were identified, including declared and environmental weeds.
There is a need to rehabilitate this section of Brown Hill Creek to improve the creek function, biodiversity, amenity and community interaction at the reserve.
Description of Proposed Works
The delivery approach seeks to achieve channel naturalisation and biodiversity outcomes with a focus on protection of significant trees, improved water quality and habitat for native species, and opportunities for increased amenity and community interaction.
This approach is cognisant of the existing features of the reserve by:
- Retaining and protecting existing significant, regulated and native trees in preference to weed and exotic species in the watercourse corridor.
- Retaining and protecting the existing heritage stone channel base.
- Improving the existing pedestrian and cycle access at the culvert crossing in the reserve.
- Retaining the existing culvert crossing at Mitchell Street.
The cross-section of the watercourse needs to vary through the reserve to satisfy these objectives and site constraints.
Once the works are completed this rehabilitated section of watercourse will convey the 1% Annual Exceedance Probability (or 1-in-100 year) design flow, as defined in the Brown Hill Keswick Creek Catchment Stormwater Management Plan.
4J Regent Street to Malcolm Street, Millswood
The project involved a doubling of the capacity of this section of Brown Hill Creek, from just downstream of Regent Street to Malcolm Street at the upstream end, including upgrade of the Regent Street culvert. The entirety of the creek in this location traverses through privately owned property and the project team engaged closely with property owners over the course of design development and during construction.
The project was delivered in a heavily constrained environment and the works were designed in collaboration with property owners to meet the flow capacity requirements while being sympathetic to the natural environment and the individual and unique objectives of each owner.
Channel solutions included a combination of stacked rock or upright concrete block constructed walls, often transitioning from one treatment to another as the creek moves through different properties. Cobbles were reinstated within the base of the channel, with more robust base treatment in specified locations where required to support higher velocity flows.
Final completion of this project included works focusing on landscape reinstatement and maintenance.
4N Cross Road to Hampton Street, Hawthorn
The section of Brown Hill Creek that runs through private properties between Cross Road and Hampton Street in Hawthorn is a known flooding hotspot – multiple properties at this location have been inundated by high flow events in 2005, 2016 and 2023 and remain vulnerable to flooding.
The condition of the existing watercourse varies along this section. For some properties, the watercourse bisects their backyard and represents an asset of high intrinsic value that is fully integrated with landscaping. For other properties, the watercourse is less maintained and delineated from useable yard areas by fences or walls.
There is an urgent need to upgrade this section of Brown Hill Creek to improve flow capacity and flood protection to private properties, while reinstating the land that is impacted by the works.
Description of Proposed Works
The delivery approach seeks to achieve the required flow capacity while integrating the channel wall selections of adjoining property owners and otherwise minimising the land that is impacted by the works.
The new channel walls will include a range of treatments from the BHKC Design Guide, including vertical concrete block walls, stacked rock walls and rock landscape walls. New safety fences will be installed along the channel walls through private property and the existing cobble base of Brown Hill Creek will be retained and replenished with new stones.
While some trees are required to be removed for the upgrades, most of these are weed and exotic species, and on completion of the channel works an extensive revegetation program will be undertaken in consultation with property owners to plant new trees, shrubs and groundcovers along the creek corridor but outside of the main channel.
The new culvert crossing at Hampton Street will include the relocation of some existing utility services and new footpaths on both sides of the road.
Once the works are completed this upgraded section of watercourse will convey the 1% Annual Exceedance Probability (or 1-in-100 year) design flow as defined in the Brown Hill Keswick Creek Catchment Stormwater Management Plan.
View the project fact sheet here.
4Q Hawthorn Reserve
The City of Mitcham upgraded the Hawthorn Reserve precinct in 2018/19 and the creek upgrades were expedited to coincide with this project.
The creek has been widened to ensure sufficient capacity and the banks have been laid back with native plantings in the area adjacent the Mitcham Library to retain a natural setting. Stepping boulders and logs have also been installed to create an active nature play space for use when the creek is dry or not flowing. Further downstream, rock filled gabions have been installed and a floodwall has been constructed at George Street to contain creek flows.
4T Betty Long Gardens
The condition of the existing Brown Hill Creek watercourse through Betty Long Gardens and adjacent private property has been significantly impacted by high flow events in 2005, 2016 and 2023 which have caused erosion of the creek bed and undermining of the channel banks.
An arborist assessment for this section of watercourse identified various tree species, including both native and invasive types, and some high value significant trees that are in good health.
An ecological assessment identified only nine bird species and no native mammals at the project site, with no hollow-bearing trees limiting the nesting opportunities for fauna. The assessment also identified a predominance of invasive weeds – 38 species of weeds were identified, including declared and environmental weeds.
There is an urgent need to rehabilitate this section of Brown Hill Creek to protect the significant Kauri trees that are located along the top of the western bank and to improve the creek function, biodiversity, amenity and community interaction at the reserve.
Description of Proposed Works
The delivery approach seeks to achieve channel naturalisation and biodiversity outcomes with a focus on protection of significant trees, improved water quality and habitat for native species, and opportunities for increased amenity and community interaction.
New gabion walls will be constructed for the channel banks. The gabion baskets can be installed with limited disturbance to the existing channel banks and will be filled with sandstone quartzite stones to prevent erosion. The baskets are durable and flexible and will tolerate future ground movements.
A new 1,200mm high ‘open style’ safety fence will be installed along the top of the gabion walls in Betty Long Gardens Reserve and the existing cobble base of Brown Hill Creek will be retained and replenished with new stones.
While some trees are required to be removed for the upgrades, most of these are weed and exotic species, and on completion of the channel works an extensive revegetation program will be undertaken to plant new trees, shrubs and groundcovers along the creek corridor but outside of the main channel.
Once the works are completed this rehabilitated section of watercourse will convey the 1% Annual Exceedance Probability (or 1-in-100 year) design flow, as defined in the Brown Hill Keswick Creek Catchment Stormwater Management Plan.
View the project fact sheet here.