Flowpath Engineering Portal
GD01 Stormwater Device Sizing — Swales, Check Dams & Bioretention
Size stormwater treatment devices per Auckland Council GD01. Design swales, check dams, and bioretention systems with hydraulic checks for water quality and flood events.
What this tool does
Swale Design
Size grassed and vegetated swales with Manning's equation, dual-condition analysis for water quality and 10% AEP flows.
Check Dam Sizing
Design check dams within swales using weir flow equations. Determine spacing, number, and storage volumes.
Bioretention Devices
Size bioretention systems with ponding, media, drainage and storage layers. Verify detention and retention compliance.
GD01 Compliant
All calculations follow Auckland Council's GD01 guideline document for stormwater management devices in the Auckland region.
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Open GD01 Device SizingPart of the Flowpath Engineering suite of free civil engineering tools for New Zealand.