Dover Street Reserve Stormwater Basin
Client:
Swanbury Penglase and City of Port Adelaide Enfield
Location:
Blair Athol, SA
In 2021 Tonkin was engaged by Landscape Architects Swanbury Penglase to provide civil, stormwater and structural engineering services for the upgrade of Dover Street Reserve for Port Adelaide Enfield Council.
What we did
While the reserve was primarily set aside to serve a regional flood protection function, Council also wanted the area to double as useful recreational space as a part of the urban renewal of the area.
Tonkin has a long association with this project, having undertaken previous stormwater modelling work in the area over a number of years. In 2018 Tonkin was engaged to develop the initial concept design for the basin at the reserve.
Following further site investigations and land purchases, in 2021, the detailed design of the Dover Street reserve basin and landscaping was put out to tender. Based on our wealth of previous work and depth of understanding the Swanbury Penglase and Tonkin team was selected to undertake the detailed design phase of the project.
Tonkin has a long association with this project, having undertaken previous stormwater modelling work in the area over a number of years. In 2018 Tonkin was engaged to develop the initial concept design for the basin at the reserve.
Following further site investigations and land purchases, in 2021, the detailed design of the Dover Street reserve basin and landscaping was put out to tender. Based on our wealth of previous work and depth of understanding the Swanbury Penglase and Tonkin team was selected to undertake the detailed design phase of the project.
Tonkin’s scope of services included:
- Preparation of demolition plans and general construction layout plans
- DBYD, services investigations and boundary survey
- Long sections and cross sections for kerb lines and modified street junctions
- Long sections and cross sections for footpaths
- Design details for concrete edging, retaining walls, fencing, footpaths/half basketball court pavement, kerbing, and road reconstruction
- Detailed earthworks plan with cut and fill volumes
- Structural detailing and safety in design assessments
- Detailed stormwater drawings (long sections, setout, pit and pipe schedules)
- Geometric set out via the 12D model.
What we achieved
The upgraded reserve and detention basin was officially unveiled at a community celebration in December 2022.
This project includes:
This project includes:
- Provision of flood protection for current and future residents
- Development of an open space to support the health and wellbeing of residents
- Updated play spaces and community facilities
- Closing off a portion of Anson Street to extend the useable open space with Rushworth Reserve.
The reserve will now act as a stormwater detention basin which will flood during heavy rainfall events to increase the capacity of the local stormwater system and reduce flood risk.
Stormwater pipes and the natural topography around the local area lead to the reserve, and during heavy downpours it will be able to hold up to 14,000 cubic metres of water – equivalent to more than five Olympic sized swimming pools. Water will be held in the basin, then released back into the stormwater system over time.
Tonkin’s experience working with Local Government to design user-friendly recreational spaces, combined with our decades of specialist stormwater management expertise, helped deliver an exceptional outcome that will benefit the local community for many years to come.
How we made a difference
This project involved skilled engineering that carefully balanced use of the space with effective stormwater management.
To reduce the frequency of inundation of the large amount of open space at the bottom of the basin, Tonkin undertook detailed hydraulic modelling to allow the design of a splitter box at the downstream end of the basin. The box has an internal baffle wall set as high as practically possible, so that day-to-day stormwater flows don’t spill into the basin, while still being low enough to allow the full flood flow within the pipe to be able to spill into the basin.
This design consideration maximised the value of the open space by reducing how often it is inundated.
Based on our hydraulic modelling and knowledge of the area, Tonkin identified that downstream flood levels had the potential to backflow up the drainage system and fill up the basin, which meant it would have little spare capacity to detain locally produced flood waters. This potential issue was resolved in the design by incorporating a flood gate downstream of the basin that would prevent these backflows from occurring.
Based on our hydraulic modelling and knowledge of the area, Tonkin identified that downstream flood levels had the potential to backflow up the drainage system and fill up the basin, which meant it would have little spare capacity to detain locally produced flood waters. This potential issue was resolved in the design by incorporating a flood gate downstream of the basin that would prevent these backflows from occurring.
This was an example of Tonkin’s higher-level understanding of the local drainage system which helped us deliver bespoke solutions for this complex project.