Project location
- 109 Timor Avenue, Loganholme
- Located near the intersection between Timor Avenue and Bryants Road in the Tingalpa Creek Catchment
- Approximately 2013m² in size
- Prior to the below works the site contained structures
- Lot 83 on RP118024
Project summary
- Construction of childcare centre
- Creation of internal access driveway and car parking
- Connection to sewer and water services
- Constructing new stormwater infrastructure
Our role
CWD Group undertook the following scope of works for the project at 109 Timor Avenue, Loganholme:
- Stormwater Management Plan
- Undertake hydrologic calculations to determine discharges from the site for the 1, 2, 5, 10, 20, 50 and 100 year ARI events for the existing and proposed development scenarios
- Determine lawful point of discharge and conceptual sizing of required stormwater infrastructure
- Undertake conceptual design of proposed stormwater infrastructure, including demonstration of no adverse impacts on stormwater runoff conditions for neighbouring properties due to the proposed developments
- Ensure requirements of the SPP are met in terms of water quality objectives
- Prepare conceptual stormwater drawing suitable for submission to council
- Prepare a report which is undertaken and certified by an RPEQ suitable for submission to council for development approval
- Flood – Overland Flow Assessment
- Undertake a site visit to gain an appreciation for flow path and catchment conditions (if required)
- Calculate rainfall run-off contributing to overland flow onsite for the 50yr ARI event
- Define the existing overland flow path
- Model design scenario (if needed), up to one iteration allowed for
- Compare pre and post-development conditions and assess impacts (if needed)
- Determine post-development flood characteristics such as flood depth, extent and velocity
- Evaluate the impact of the development for neighbouring properties
- Determine appropriate minimum habitable floor levels on site consistent with the planning scheme
- Prepare a certified (RPEQ) report detailing all model assumptions inputs and results suitable for submission to council. The report will address the relevant portions of the planning scheme accordingly.
- Concept Plans
- Prepare concept plans for earthwork, sewer and water as outlined in the pre-lodgement minutes
The project
As the project site already contained an overland flow path provision, as required under development conditions, the key features for overland flow that CWD Group had to take into consideration were the location of future structures within the flow path and the locations of the stormwater infrastructure on site, which would discharge the run-off. These were important considerations, as the development would result in peak discharges, and the proposed structures on the site impeding the flow path may have had negative impacts on the flood levels of neighbouring properties.
In response to these constraints, CWD Group proposed stormwater detention tanks be constructed as part of the development to match pre-development discharges from the site, ensured the development did not cause an actionable nuisance on existing flooding conditions and implemented stormwater quality treatment devices to offset the impact of the development.
Value added by CWD Group
CWD Group’s ability to assess current site conditions and develop strategies to manage or offset flood flow challenges ensured that the client was able to confidently continue with their development without impacting on the flood levels of any neighbouring properties. CWD Group’s reputation for efficient time management was proven once again, as work was completed promptly and to a high professional standard, allowing the project to progress quickly.
