Shoreline Restoration and Erosion Control in Ontario: Armour Stone, Permits and Costs

Why Shoreline Erosion Happens on Ontario Lakes

Shoreline erosion is rarely one event. It is several forces working on the same soil year after year, and a fix only lasts if it answers all of them.

• Waves. The longer the stretch of open water in front of your lot (the fetch), the bigger the waves a strong wind can build. A lot facing kilometres of open lake lives a different life from one in a sheltered bay.
• Ice push. Expanding ice, or broken ice driven by spring wind, shoves onto the shore with enormous force. It bulldozes loose stone, tears out roots, and tilts walls never built to resist it.
• High water years. When levels run high, waves break against the bank instead of the beach. The Great Lakes saw this in 2017 and again in 2019 to 2020.
• Boat wake. On narrow channels and busy lakes, wake does as much work as wind, all summer long.
• Removed vegetation. The one factor owners control. Native shrubs and grasses knit the bank together with deep roots. Mow lawn to the water and those roots are gone.

Runoff from above is the forgotten factor. Downspouts and patios draining toward the lake cut gullies into the top of the bank, and no stone at the waterline fixes a slope being washed out from behind.

Soft Shoreline Restoration: Planting and Bioengineering

Soft approaches use living plants, sometimes helped by biodegradable materials, to hold the soil. Ontario agencies generally favour them where exposure allows: they protect fish habitat, filter runoff, and strengthen with age.

Vegetated buffers

A buffer is a strip along the water planted with native species instead of lawn. A few metres of dogwood, willow, ninebark and native grasses binds the soil, breaks up waves in high water, and catches fertilizer before it reaches the lake. On sheltered frontage it is often all the protection needed.

Live staking and coir logs

Live staking drives dormant willow or dogwood cuttings into the bank, where they root and sprout. It is cheap and works best in late fall or early spring, which fits neatly around in-water timing restrictions. Coir logs, tubes of packed coconut fibre staked along the toe, absorb small waves and trap sediment for the two or three years plantings need to root, then break down. They buy time; they are not permanent structures.

The honest limit is exposure. Where a long fetch or regular ice push hits the shore, plants can be stripped out faster than they establish. The answer there is a hybrid: stone at the toe where the energy lands, planting above where roots can hold the bank.

Hard Shoreline Protection: Rip Rap and Armour Stone

When planting cannot survive the forces involved, stone does the heavy lifting. Both common forms of hard shoreline protection in Ontario are normally built as a sloped revetment, not a wall.

Rip rap revetment

Rip rap is a layer of angular quarried stone on a regraded slope. Waves run up the rough face and lose energy between the stones. What decides whether it lasts is underneath: geotextile filter fabric, often with a bedding layer of smaller stone, so soil cannot wash out through the gaps. Rip rap dumped on bare soil looks fine for a season, then slumps.

Armour stone shoreline revetments

An armour stone shoreline uses large quarried blocks, often limestone, with individual pieces that can weigh well over a tonne. That weight resists waves and ice that would rearrange smaller rip rap. The stone is placed in a sloped or stepped arrangement, keyed into the lake bed at the toe, with fabric and smaller stone behind. On exposed sites, stone size, slope and toe depth should come from an engineer, and approving agencies often ask for that design.

For armour stone on dry land, such as terracing a sloped yard, see our guide to armour stone retaining wall costs. The stone is the same; the design rules at the water are not, because a shoreline structure must survive scour at its toe and ice on its face, and it sits in fish habitat.

Why a vertical waterfront retaining wall is usually the wrong answer

Many older cottages have a vertical concrete, timber or steel wall at the water. A vertical waterfront retaining wall reflects wave energy instead of absorbing it. The reflected wave digs into the lake bed at the base, called scour, until the toe is undermined and the wall tips forward. Energy also deflects sideways, so neighbouring shorelines erode faster at the ends, called flanking. That is why sloped revetments are usually preferred and why agencies often push back on new vertical walls. The common fix for a failing wall is controlled removal, a regraded stable slope, and stone with planting above. On tight lots, a stepped armour stone face with a stone toe is a frequent compromise.

Local Notes: Lake Simcoe, Lake Scugog, the Kawarthas and Georgian Bay

Swimpool 360 is based in Zephyr, a short drive from the south end of Lake Simcoe. These general notes explain why two shorelines an hour apart can need very different answers.

Approvals for Shoreline Erosion Control in Ontario

Shoreline erosion control sits where several sets of rules overlap, and which apply depends on the lake, who owns the lake bed, and where the work happens. Treat this as the usual list and confirm yours with the conservation authority and municipality before finalizing a design.

How the layers fit together

Call the conservation authority first. It can confirm whether your lot is regulated, what an application needs, and which other agencies usually get involved on your lake. Some parts of Georgian Bay and the northern Kawarthas have no conservation authority, leaving more to the province, federal agencies and the municipality. The federal process starts with the Projects Near Water self-assessment; if your project cannot avoid harming fish habitat with the standard measures, you request a DFO review.

In-water timing windows

In-water work is limited to periods when fish are not spawning or incubating eggs. On most southern Ontario lakes the window is typically closed through spring into early summer to protect bass, pike and walleye. Lakes with fall spawners, such as lake trout and whitefish in Lake Simcoe, can carry a fall restriction too. Your window is set for your lake and written into your approvals, so confirm it before booking anyone.

Shoreline Restoration Cost in 2026

Shoreline work is priced per linear foot of frontage. These are typical 2026 Ontario guidance figures, not quotes, assuming an excavator can reach the water from land.

What moves the number

• Access, above everything. A flat lot with a driveway to the water is the cheapest site. A steep bank, a narrow lot between cottages, a septic bed in the way, or barge delivery can double the cost of the same frontage.
• Bank height and exposure. A four metre bluff facing open water needs more regrading, bigger stone and a deeper toe than a low bank in a bay.
• Removal. Taking out an old wall or timber crib and disposing of it properly is a real line item.
• Soft costs. Surveys, engineering and permit fees are usually extra. Budget them separately.

Rule of thumb: settle the approach before collecting prices. A cheap quote for a vertical wall where agencies will only approve a sloped revetment is a quote for something you may never be allowed to build.

The Project, Step by Step

Shoreline projects follow the calendar more closely than most landscaping work.

1. Assess the site (late summer or fall). Note bank height, what is eroding, where runoff comes from and how a machine reaches the water. Low water shows the toe clearly.
2. Pre-consult the conservation authority (fall or early winter). Learn what they will accept on your lot and what drawings they need.
3. Design and apply (winter). A sketch may do for planting; armour stone on an exposed shore usually needs a survey and engineered drawing. Submit applications and the DFO self-assessment. Winter is permit season because approvals take months.
4. Build inside the window (late summer or fall). Install sediment controls such as a silt curtain, remove any failed structure, regrade, lay fabric and bedding stone, then place stone from the toe up.
5. Plant while dormant. Shrubs and live stakes go in above the stone in fall or the next spring, with erosion blanket on bare soil.
6. Inspect every spring. After ice out, look for displaced stone, exposed fabric, slumping or ice and storm damage. Early repairs are cheap.

Expensive Mistakes to Avoid

Dumping fill or concrete rubble

Pushing soil or gravel into the lake to win back a lawn edge is filling fish habitat, and it attracts enforcement. Trucking in sand for a beach is regulated for the same reason. Broken slabs and foundation chunks with rebar are not shoreline protection either: they are poorly sized, often contaminated, not accepted as clean fill, and must be dug out before proper work can start.

Building without approvals

Unapproved shoreline work can lead to stop-work orders, orders to remove it and restore the shoreline at your cost, and fines. It can also surface when a buyer's lawyer asks about permits. Slow approvals are far cheaper than undoing a finished wall.

Skipping the fabric, the toe or the top of the bank

Filter fabric and a properly keyed toe are invisible once the job is done and decide whether it lasts. Equally, stone at the waterline will not save a bank gullied by downspouts and patio runoff. Our landscaping and hardscaping service handles land-side grading, drainage, planting and stonework, and our retaining wall ideas and drainage guide explains why trapped water causes most wall failures.