Fraser Estuary sediment pilot project expands in fall 2025
A pioneering pilot project using Fraser River sediment to bolster Richmond’s flood defences is continuing this fall, with researchers preparing to place another 4,500 to 6,000 cubic metres of material at Sturgeon Bank beginning October 20 in an ongoing test of the strategy’s long-term potential.
The continuation of the Sturgeon Bank Sediment Enhancement Pilot Project, led by Ducks Unlimited Canada in close collaboration with researchers from UBC, comes after three successful rounds of sediment placement that have shown promise for restoring the tidal marshes that protect Richmond’s shoreline. The project recently received the 2025 Environmental Managers Association of BC Award for Remediation and Restoration, recognizing its significance as a model for ecological innovation in the region.
Over 21,000 cubic metres (about 1200 dump trucks worth) of sediment have been placed since 2021, repurposing material dredged from Fraser River channels that would normally be dumped offshore.
“This next phase is an important next step for the pilot project,” says Dr. Enda Murphy, assistant professor at UBC’s Department of Civil Engineering, whose team is studying the project’s effectiveness. “We’re learning lessons from each phase, and developing the tools we need to move from proof of concept to designing solutions that can work at the scale needed to actually protect communities.”
Natural flood barriers
UBC graduate student Jeremy Karkanis and research assistant Joel Chin deployed sensors this summer to track how earlier placements moved through the marsh. The data now informs computer models to pinpoint the most effective placements for both ecology and flood resilience.
“We’re trying to understand how to place sediment strategically based on wind, waves, tides and river flow,” said Dr. Murphy.
The stakes are high. Since the 1980s, Sturgeon Bank has lost at least 160 hectares of the bulrush marshes that anchor the shoreline, with less than 70 per cent remaining. Meanwhile, Richmond’s residents—most living below high tide level and protected by a 49-kilometre network of perimeter dikes—face increasing flood risks as seas are expected to rise by around half a metre by 2050.
The approach essentially mimics what nature once did. For centuries, the Fraser River carried fine sediments from inland regions towards the coast, building and feeding the marsh platforms in its estuary. But human interventions like river training and dredging have disrupted those natural pathways, diverting much of the sediment offshore instead. Today, about 3.7 million cubic metres of sediment are dredged from the estuary and almost half of that is disposed of at offshore sites in the Salish Sea each year, sediment that could be rebuilding the marshes.
“We’re giving nature a helping hand to rebuild these protections,” said Dr. Murphy. “If wave and tidal action can transport strategically placed sediment into marsh zones, they can grow vertically and keep pace with rising seas.”
New roadmap for flood protection
The collaboration, led by Ducks Unlimited Canada, with funding from Fisheries and Oceans Canada and the Province of British Columbia via the BC Salmon Restoration and Innovation Fund, Pacific Salmon Foundation, Vancouver Fraser Port Authority and Nature Force, brings together many applied research partners including UBC Civil Engineering, the National Research Council, Northwest Hydraulic Consultants, Raincoast Conservation Foundation, Simon Fraser University, and Smart Shores.
If the fall 2025 works show continued success, the project could scale up significantly across the Fraser Delta over longer timescales and serve as a sustainable model for other coastal cities facing similar challenges from sea-level rise and disappearing natural flood protection.
“We dredge and dispose at sea more sediment annually in the Fraser River Delta than anywhere else in Canada. These sediments are life-nourishing materials, and we have a unique opportunity to use the Sturgeon Bank pilot project as a springboard to start developing a new regional roadmap for reusing dredged sediments in the Fraser Delta to restore habitats, protect against flooding, and support climate adaptation instead of treating sediment as waste,” says Eric Balke, Senior Restoration Biologist with Ducks Unlimited Canada.
Unlike conventional flood infrastructure, restored tidal marshes provide multiple benefits: they buffer wave energy, store carbon, provide habitat for fish and other species, create recreational opportunities, and can be more flexible in adapting to the changing climate than rock or concrete structures.
Dr. Murphy expects their Sturgeon Bank research over the next year to provide crucial evidence about whether nature-based solutions can work at the scale needed to protect communities. “The fall 2025 placement could help decide whether nature, not hard infrastructure, can continue to be Richmond’s first line of defence as sea levels rise,” said Dr. Murphy.
