Northern Levee Cross-over Technical Design & Assessment

Client: Parks Victoria
Location: Murray and Goulburn River floodplains between Cobram, Shepparton and Barmah
Delivery Partners: 12P Consulting and Confluence Group

Overview:
Parks Victoria engaged 12P Consulting and Confluence Group to undertake a technical assessment and design project for levee crossovers located within and adjacent to Parks Victoria-managed reserves. The objective was to document, assess and provide treatment options for vehicle access points where tracks intersect flood levees—many of which had deficiencies affecting both vehicle safety and flood mitigation integrity.

Approach:
The project integrated spatial analysis, GIS, field data capture and engineering design. Tim Shilling (12P Consulting) and Chris Dwyer (Confluence Group) combined civil engineering, GIS, and waterway management expertise to deliver a comprehensive, standards-based approach.

Key Stages:

1. Desktop Analysis:
   Leveraging high-resolution LiDAR, aerial imagery, road and levee datasets, over 200 potential crossovers were identified and filtered through spatial analysis and manual verification. Prioritisation criteria included track significance, levee elevation, and proximity to recreational access points.

2. Field Investigation:
   High-priority sites were surveyed using aerial LiDAR and GNSS techniques to capture levee and track geometry referenced to AHD. Lower-priority sites were assessed using GNSS spot surveys or dumpy levels where applicable. All sites were documented in a GIS database with standardised site forms and photography.

3. Design Development:
   A suite of standard cross-over treatment drawings was developed based on field findings. These designs addressed access geometry, erosion control, levee integrity, vehicle load capacity (e.g., DEECA D6 dozer, excavators), and maintenance requirements.

4. Reporting and GIS Deliverables:
   A comprehensive GIS package and summary report was delivered, including standard design options, site-specific recommendations (upgrade, maintain, or close), and mapping for use in Parks Victoria’s asset planning.

5. Construction Support:
   Optional post-construction survey support was offered, including re-scanning to verify compliance with design levels and specifications.

Outcome:
The project produced a spatially-informed, technically robust basis for future upgrades to Parks Victoria's levee crossover network, balancing safe access with flood protection performance. It also created a replicable method for future assessment programs across other floodplain reserves.