Name
Evolution of a Managed Dykeland Realignment Landscape in a Hypertidal System
Date & Time
Wednesday, May 27, 2026, 4:00 PM - 4:15 PM
Description
Managed dyke realignment is recognized as a viable nature-based solution for flood risk reduction. After extensive consultation, baseline data collection and modelling, the Onslow North River Managed Dyke Realignment and Tidal Wetland Restoration project was implemented in the Salmon River, a hypertidal estuary in Nova Scotia. This involved removal of 3 aboiteaux, breaching the dyke in 5 locations, connecting drainage channels and building new inner dykes using borrow fill material from within the site. Full tidal exchange was restored in Nov 2021, setting the stage for restoration of 92 ha of tidal wetland and restored fish passage to the watershed including 48 km of upstream habitat. Detailed post restoration monitoring of changes in hydrology (loggers), topography (RTK GNSS and RPAS surveys), marsh surface elevation (RSET and marker horizons), vegetation (field and aerial surveys), sediment characteristics and carbon accumulation rates since 2021 characterize the ecomorphodynamic evolution of this restoring tidal wetland landscape. This evolution is driven by increased tidal volume and velocities during overmarsh tides, very high suspended sediment concentrations and sedimentation rates, and infilling, erosion and re-organization of antecedent agricultural drainage channel networks. By Year 3, almost all communities throughout the 92 ha had transitioned into new habitats. Sedimentation facilitates the establishment of halophytes but vegetation does not appear to control accretion rates. Based on elevation, hydrology and habitat data, the estimated restored wetland area now exceeds the predicted 92 ha and is associated with the position of the site high in the tidal frame near the upper tidal limit.
Location Name
DSU 303
Full Address
Dalhousie University
Halifax NS
Canada
Halifax NS
Canada
Session Type
Oral Presentation
Abstract ID
145
Speaker Organization
Saint Mary's University
Session Name
H1
Co-authors
Jennie Graham (CB Wetlands and Environmental Specialists); Samantha Crowell (CBWES Inc.), Jeremy Lundholm (CBWES Inc and Saint Mary's University); Leah Rudderham (Saint Mary's University) and Tony Bowron (CBWES Inc.)
Presenting Author
Danika van Proosdij, Saint Mary's University