Water by Design has recently produced a draft update to our Bioretention Technical Design Guidelines and are seeking feedback on it.

This update incorporates more than 10 years of additional bioretention design knowledge into an already widely used document. Some key areas where changes have been made to the document include:

• Increase of the minimum filter media depth from 400 mm to 600 mm. Removal of any additional depth requirements for trees (Section 2.4).
• New section on functional design (Section 3.1).
• Enhanced guidance on how to configure large bioretention systems (Section 3.4.3.1).
• New guidance and clarification regarding collocation with detention basins (Section 3.4.9) and flood immunity requirements (Section 3.4.10).
• Further guidance on the use of energy dissipation and alignment of sediment forebays (Section 3.5.3.3).
• Reduced requirements for underdrainage cleanout points (Section 3.6.1.1).
• Alterations to pit and riser configurations for saturated zone systems (Section 3.6.1.4).
• Guidance on the use of temporary upstands during plant establishment (Section 3.6.1.5).
• Expanded vegetation design section with much greater focus on planting to create resilient low-maintenance ecosystems. The use of trees is now the default in all bioretention unless there is an overriding reason not to include them (Section 3.7).

A full list of changes is available in Section 1.1. of the guideline.

To view the draft and provide feedback, please download the following documents and return to jack.m@hlw.org.au by Friday 1 May 2026:

• Bioretention Technical Design Guidelines (2026 DRAFT)
• Feedback form: Bioretention Technical Design Guidelines

We will also be hosting a stakeholder consultation webinar on this draft document on Thursday 16 April 2026.

Find out more or register: 
https://events.teams.microsoft.com/event/930b17d0-0ce7-4498-b945-61d0756f80cd@26c5ee24-eca4-49d5-af7c-892ab537cfed

If you would like to know more or have any questions, please contact jack.m@hlw.org.au.

The Urban Stormwater (USW) and Erosion and Sediment Control (ESC) capacity building program is proudly funded by the Queensland Government’s Water Quality Investment Program, delivered by the Department of the Environment, Tourism, Science and Innovation.