Bank Erosion Control Methods Across Canadian Shorelines

Coastal sediment dynamics and erosion on the Yukon coast, March 2025. Image: Copernicus/ESA via Wikimedia Commons (CC BY-SA).

Bank erosion along Canadian freshwater and coastal shorelines is driven by a combination of hydraulic forces — flow velocity, wave action, ice push — and geotechnical factors including bank height, soil cohesion, moisture content, and the presence or absence of root reinforcement. Selecting an appropriate control method requires matching the technique to the dominant erosion mechanism at a given site.

This article reviews the main categories of erosion control used in Canadian practice: bioengineering methods, hard armour, hybrid approaches, and geotextile-based systems. It also identifies the site conditions under which each approach is most appropriate.

Classifying erosion before selecting a method

Three broad erosion types are commonly encountered along Canadian bank sections:

• Surficial erosion — removal of near-surface material by raindrop impact, overland flow, or wave swash. Common on exposed upper bank faces lacking vegetation cover.
• Bank toe scour — undercutting of the base of the bank by sustained or high-velocity flow. Creates overhanging or near-vertical bank faces susceptible to mass failure.
• Mass failure — block slumping or rotational failure of bank sections, often following saturation of the bank profile during or after flood events.

Surficial erosion is most amenable to vegetation-only approaches. Bank toe scour typically requires structural intervention at or below the waterline before vegetation can succeed. Mass failure often reflects a combination of bank geometry, soil type, and hydrology that may require geotechnical assessment before restoration.

Bioengineering methods

Bioengineering — the use of living plant material as a structural component of bank stabilisation — is the preferred approach in most low-to-moderate energy shoreline environments in Canada. The live plant material provides structural function immediately after installation and biological function as roots establish and expand.

Live staking

Live stakes are dormant cuttings from fast-rooting woody species — predominantly willows and dogwoods — installed as vertical rods driven into moist bank material below the ordinary high-water mark. Stake diameter is typically 2–5 cm; length 40–90 cm. They are installed in late winter to early spring before bud break to maximise rooting success.

Black willow (Salix nigra) and sandbar willow (Salix exigua) have high rooting rates from live stakes across most of Canada. Red osier dogwood (Cornus sericea) is used in more sheltered positions and in interior locations where willows are less common. Live staking alone is most appropriate on lower bank faces where soil moisture is consistently adequate for rooting.

Brush layering

Brush layering involves placing horizontal layers of live branch material — again typically willows — between compacted fill lifts on an eroded bank face. Each layer is partially buried with the branch tips protruding slightly from the bank face. As the cut branches root, roots extend laterally and downward through the fill, reinforcing multiple layers simultaneously.

This approach is used on reconstructed or re-graded bank sections where the existing bank profile has failed or been intentionally cut back to a stable angle. The combination of mechanical compaction and root reinforcement from established brush layers can provide substantial resistance to subsequent erosion.

Fascines (brush bundles)

Fascines are bundles of willow or dogwood branches, typically 15–20 cm in diameter and 2–4 metres long, bound with natural twine and installed in shallow trenches along the bank contour. They are placed at intervals to intercept runoff and trap sediment on upper bank faces and reduce velocity-induced scour.

Fascine installation is practical on moderate slopes where machinery access is limited, and is commonly used in combination with live staking to provide both structural and erosion-interception functions during the establishment window.

Hard armour approaches

Where erosion energy is too high for bioengineering approaches alone — at the bend of an actively meandering stream, along exposed lakeshore sections subject to storm wave action, or at bridge and culvert approaches — hard armour remains a necessary tool.

Rock riprap

Rock riprap (dumped or hand-placed angular stone) is the most widely used hard armour material in Canadian shoreline and bank protection works. Properly sized riprap dissipates flow energy through the void spaces between stones and resists displacement when stone size, gradation, and layer thickness are matched to design flow conditions.

Under current provincial guidance in Ontario (e.g., under the Conservation Authorities Act permitting framework) and equivalent regulations in other provinces, riprap installation below the ordinary high-water mark requires permits. Sizing is typically based on mean water velocity at the bank face or design wave height for lakeshore applications.

A known limitation of riprap is displacement of erosion energy: hardened sections can deflect flow toward unprotected adjacent banks, potentially accelerating erosion there. This concern drives the preference for bioengineering where energy levels permit, particularly in regulated channels where the full bank system can be considered holistically.

Gabion structures

Wire-mesh gabion baskets filled with rock are used in situations where available stone is smaller than would be suitable for free-placed riprap, or where a more defined structural face is needed. Gabion walls and mattresses are used at bank toes on actively eroding sections and as toe aprons beneath riprap upper bank protection.

Galvanised or PVC-coated wire is standard in Canadian practice given the corrosive potential of freshwater and freeze-thaw cycling. Gabion structures have a finite service life tied to wire durability — typically 20–40 years in freshwater environments depending on water chemistry and installation quality.

Geotextile and vegetated systems

Erosion control geotextiles — woven and non-woven fabrics, coir mats, jute mesh, and rolled erosion control products (RECPs) — are used to provide immediate surface protection on seeded or planted bank faces, holding soil in place through the vegetation establishment period.

Coir (coconut fibre) blankets are a preferred material in Canadian restoration practice because they are biodegradable — typically over three to five years — and decompose into organic matter that improves surface soil conditions as vegetation establishes. Synthetic RECPs provide longer-term structural function in areas where permanent vegetation cover is difficult to establish.

Vegetated geosynthetic systems

Pre-vegetated erosion control rolls — coir or synthetic mesh tubes seeded with native grasses and forbs — can be installed at the bank toe or along the bank face to provide immediate erosion resistance combined with ongoing root reinforcement as the plants establish. These systems are used on moderate-gradient banks where immediate structural protection is needed but hard armour is not warranted.

Arctic and subarctic shorelines

Northern Canadian shorelines present specific challenges. Permafrost degradation driven by warming temperatures is accelerating erosion along the Yukon and Northwest Territories coastlines and along northern river banks. The dominant erosion process in these environments — thermal erosion and thaw slumping — is not amenable to conventional bioengineering or riprap approaches, as the primary driver is ground ice melt rather than hydraulic shear alone.

Satellite monitoring data (including Copernicus satellite observations) has documented measurable coastline retreat along sections of the Beaufort Sea and Hudson Bay coasts. Research on adaptation approaches for these environments is ongoing through Natural Resources Canada and northern territorial bodies.

Selecting among methods: a practical framework

A simplified decision sequence for Canadian bank stabilisation projects:

1. Identify the dominant erosion mechanism (surficial, toe scour, or mass failure).
2. Assess flow velocity or wave energy at the bank face during design events.
3. If energy is low to moderate and bank height is below ~1.5 m: vegetation-only or bioengineering approaches are appropriate candidates.
4. If toe scour is present or bank height exceeds ~1.5 m: structural toe protection (riprap apron, fascine, vegetated roll) should precede or accompany planting.
5. If mass failure has occurred or the bank is in highly erodible fine material: consult a geotechnical engineer before proceeding.
6. In all cases: confirm regulatory requirements before beginning physical works.

For guidance on native plant species and planting methods that support these bioengineering approaches, see using native plants to stabilize shoreline banks.