Greenfield subdivision design — 124-lot Logan release.
Case study: full civil engineering documentation for a 124-lot greenfield residential subdivision in Logan City Council — including road design, stormwater management, sewer reticulation, water reticulation and lot grading to SEQ Code.
Project overview
A SE Queensland developer engaged ASTCAD for the full civil engineering documentation of a 124-lot residential subdivision within Logan City Council. The 13.4 ha site required staged release across three phases, with retention basin design, road reticulation and full lot servicing.
The challenge
The site sloped 4-7% across an undulating ridge, requiring careful balance between cut/fill volumes and floor level requirements. SEQ Code stormwater detention requirements applied, plus the site fed into an existing council sewer pump station near capacity. Council required certified design and construction documentation before earthworks approval.
Our approach
- Road design to Logan City planning scheme with 18 m corridor widths
- Stormwater management with on-site detention to SEQ Code
- Sewer reticulation design with capacity check on receiving pump station
- Lot grading optimised for cut/fill balance — net earthworks under 8,000 m³
- Staged construction plan supporting three release phases
Deliverables
- Civil engineering drawings (124 sheets across roads, drainage, services)
- Hydraulic and hydrological reports per SEQ Code
- Sewer capacity assessment and council approval letter
- Staged construction methodology
- QSurv-ready plans for lot creation
Outcome
Stage 1 of the subdivision was civil-complete within 7 months of design sign-off. Council inspections passed first time with no remediation works required. Stages 2 and 3 are under construction with the same documentation set.