Product Overview

Summary: This Hydrology and Floodplain Management Safe Operating Procedure provides a structured, defensible approach to assessing flood risk, planning mitigation measures, and managing floodplain activities in line with Australian WHS and environmental requirements. It supports organisations to protect workers, the public, and assets from flood-related hazards while ensuring projects and operations remain compliant, resilient, and sustainable.

Floods are among Australia’s most frequent and costly natural hazards, with serious implications for worker safety, public safety, infrastructure resilience and business continuity. This Hydrology and Floodplain Management Safe Operating Procedure sets out a clear, repeatable method for assessing flood behaviour, defining floodplain constraints, and integrating flood risk controls into planning, design, construction and ongoing operations. It translates complex hydrological and hydraulic concepts into practical steps that can be consistently applied across projects, sites and regions.

The SOP helps organisations move beyond ad hoc assessments and undocumented local knowledge by providing a formalised framework for data collection, modelling, risk assessment, and decision-making. It addresses how to identify and control flood-related hazards to workers and the community, support safe access and egress, protect critical infrastructure, and coordinate with emergency services during flood events. By adopting this procedure, businesses can demonstrate due diligence under Australian WHS legislation, satisfy council and regulator expectations, and embed flood resilience into their asset management and project delivery processes.

This document is particularly valuable for councils, utilities, mining and resources operations, transport infrastructure owners, and developers working in or near flood-prone land. It clarifies roles and responsibilities, sets minimum technical standards, and provides a structured process for reviewing and updating flood information as catchments change over time due to development, climate variability and land-use change.

Key Benefits

• Ensure a consistent, defensible methodology for hydrological assessment and floodplain management across all projects and sites.
• Reduce flood-related safety risks to workers, contractors and the public through structured hazard identification and control measures.
• Demonstrate compliance with WHS duties, local government floodplain policies and relevant Australian Standards and guidelines.
• Support informed, transparent decision-making for land use planning, infrastructure design and emergency access during flood events.
• Improve organisational resilience by integrating flood risk considerations into asset management, maintenance and emergency planning.

Who is this for?

• Civil Engineers
• Hydrologists
• Floodplain Managers
• Infrastructure Project Managers
• Local Government Asset Managers
• WHS Managers
• Environmental and Sustainability Managers
• Emergency Management Coordinators
• Construction Site Supervisors
• Consulting Planners and Development Assessors

Hazards Addressed

• Drowning and entrapment risks for workers and the public in floodwaters and rapidly rising streams
• Vehicle instability, loss of control and wash-off due to flooded roads, causeways and work areas
• Structural failure or damage to embankments, levees, culverts, bridges and retaining structures during flood events
• Erosion, scour and slope instability impacting work areas, foundations and access routes
• Inundation of electrical installations, pump stations and switchboards creating electrocution and fire risks
• Contaminated floodwater exposure, including sewage, chemicals and debris affecting worker health
• Isolation of workers and communities due to cut access routes and compromised evacuation paths
• Struck-by hazards from floating debris and failure of temporary works in flood conditions
• Manual handling and fatigue risks associated with emergency sandbagging and flood response activities

Included Sections

• 1.0 Purpose, Scope and Objectives
• 2.0 Definitions and Key Hydrological Concepts
• 3.0 Roles, Responsibilities and Competency Requirements
• 4.0 Applicable Legislation, Standards and Local Policies
• 5.0 Data Collection, Catchment Characterisation and Information Sources
• 6.0 Hydrological and Hydraulic Assessment Methodology
• 7.0 Flood Hazard Identification and Risk Assessment
• 8.0 Floodplain Management Principles and Design Criteria
• 9.0 Integration with Land Use Planning and Development Assessment
• 10.0 Worker and Public Safety Controls in Flood-Prone Areas
• 11.0 Access, Egress and Evacuation Planning for Flood Events
• 12.0 Infrastructure and Asset Protection Measures
• 13.0 Construction Phase Controls in Flood-Exposed Work Areas
• 14.0 Monitoring, Warning Systems and Trigger Action Response Plans (TARPs)
• 15.0 Emergency Preparedness, Response and Recovery Procedures
• 16.0 Environmental and Cultural Heritage Considerations in Floodplains
• 17.0 Documentation, Recordkeeping and Reporting Requirements
• 18.0 Consultation, Communication and Stakeholder Engagement
• 19.0 Training, Induction and Competency Verification
• 20.0 Review, Audit and Continuous Improvement

Legislation & References

• Work Health and Safety Act 2011 (Cth) and equivalent state and territory WHS Acts
• Work Health and Safety Regulations 2011 (Cth) and equivalent state and territory WHS Regulations
• Safe Work Australia – How to Manage Work Health and Safety Risks: Code of Practice
• Safe Work Australia – Managing the Work Environment and Facilities: Code of Practice
• Australian Rainfall and Runoff (ARR 2019) – A Guide to Flood Estimation
• AS/NZS ISO 31000:2018 Risk management – Guidelines
• AS 5334:2013 Climate change adaptation for settlements and infrastructure – A risk based approach
• Relevant state floodplain development manuals and guidelines (e.g. NSW Floodplain Development Manual)
• Local government floodplain risk management policies and development control plans