Norman Griffiths Oval flood studies

This project update on the Norman Griffiths Oval upgrade is current as at 18 July 2025.

The update includes the release of several key documents, along with a summary of current progress and next steps.

These documents provide important context around drainage, flooding and ecological considerations and reflect Council's ongoing work to deliver this.

Orion Site Specific Flood Modelling Report

Orion Group - Civil Engineering Design Review and Flood Impact Assessment Certification for Norman Griffith Oval Refurbishment(PDF, 29MB)

Draft documents

A Review of Environmental Factors (REF) is undertaken where an Environmental Planning Instrument identifies an activity as ‘development permitted without consent’ and development consent under the NSW Environmental Planning & Assessment Act is not required. Instead, the environmental impacts of the activity are considered through the REF assessment. This process is commonly undertaken for a wide range of public authority infrastructure projects across NSW.

If a proposed activity needs to be altered or modified, the REF document will need to be revised to incorporate the amendment and be reassessed. If a determination has been made, and a modification (eg. a change or addition) is proposed, the modification will need to be assessed by either preparing a new REF document, or a REF document addendum.

During construction it was identified that a diversion wall and formalisation of the flow path was required to ensure the field was flood free up to a 1% AEP event and ensure potential for synthetic field materials and organic infill is minimised. This addendum has been prepared to consider the design details not included during assessment of the original REF and review the potential impacts of altered overland flows.

Please note: the documents below are drafts only and subject to change pending final design and further assessment. They are being provided at this stage to keep the community informed about current investigations and technical inputs.

Draft Review of Environmental Factors (REF) variation addendum for design updates including assessment of the overland flow path ecological impact assessment(PDF, 533KB) (Please note: this REF variation is not final. Content may change as the design is refined).

Draft REF supporting documents

Appendix 16 flood model review - Orion Group - Civil Engineering Design Review and Flood Impact Assessment Certification for Norman Griffith Oval Refurbishment(PDF, 29MB)

Appendix 17 updated plans showing variation details(PDF, 12MB) - all updated plans showing variation

Appendix 18 SES advice February 2025(PDF, 1001KB)

Appendix19 FFIA addendum - Thrive Ecology - proposed changes to stormwater mitigation works at Norman Griffiths Oval(PDF, 4MB)

Appendix 20 Arborist Advice Council Tree Management Officer Advice(PDF, 5MB)

Appendix 21 AIA TPP Norman Griffiths Sports Field(PDF, 2MB)

Appendix I - Tree Data(PDF, 398KB)

Appendix II - Arboricultural Impact Assessment Drawings(PDF, 8MB)

Appendix III - Tree Protection Plan Drawings(PDF, 8MB)

Catchment Flood Study -

Draft Lane Cove Northern Catchments Flood Study(PDF, 7MB)

Please note: this study has been undertaken in parallel to the independent Norman Griffiths site investigations. Although the intention is to include the final oval design, this version does not currently incorporate all design elements informed by the Norman Griffiths oval site-specific flood report undertaken by Orion consulting. In addition, further updates may be required following review by Council’s Flood Risk Management Committee prior to formal public exhibition.

This document is a preliminary draft and will be placed on public exhibition in the upcoming months, following formal review and endorsement by Council’s Flood Risk Management Committee.

Appendix B Survey(PDF, 15MB)

Appendix C flood study newsletter - Lane Cove Northern Catchments(PDF, 2MB)

Appendix D drains model update(PDF, 3MB)

Appendix F(PDF, 53MB)

Appendix G(PDF, 2MB)

Appendix H(PDF, 32MB)

Figures(PDF, 23MB)

The studies above build upon previous flood studies undertaken during project development and design including:

2018 Jacobs investigations - Norman Griffiths Oval Flood Assessment Final Compendium Report(PDF, 47MB)

2020 BMT Report - Norman Griffiths Oval - Flood Risk Investigation(PDF, 20MB)

2023 Norman Griffiths Oval West Pymble Review of Environmental Factors - version 9(PDF, 4MB)

Appendix 9 - Stormwater System Technical Memo - Norman Griffiths Oval(PDF, 861KB) (Note for further REF documentation please refer to documents on the Norman Griffiths Oval upgrade page)