Atherley and the Orillia end of Lake Simcoe

The Atherley Narrows is where Lake Simcoe ends and Lake Couchiching begins. It is also where the City of Orillia meets Ramara Township, and where Highway 12 crosses the water. For a waterfront buyer, that makes this small area unusually confusing: two lakes, two municipalities, two sets of rules and one shared mailing address.

This page sorts out which is which. For life in the city generally, see the Orillia area guide on rossmanteam.com.

What exactly is the Atherley Narrows?

It is the short, shallow channel that carries water from Lake Simcoe north into Lake Couchiching. There is no lock. The two lakes are managed together for water levels by Parks Canada through the Trent-Severn Waterway, so a high-water year on Simcoe is a high-water year on Couchiching too. rossmanteam.com's water levels, boating and ice guide explains how Parks Canada manages both lakes.

Parts of the Narrows lakebed are the Mnjikaning Fish Weirs National Historic Site. The narrow passage funnelled fish moving between the lakes, and the shallow water let people build wooden weirs there. Parks Canada manages the site, which includes the marked navigation channel (first dredged in 1856–57), an older channel to the northeast and the surrounding marshland. If you boat or paddle here, stay in the marked channel.

Which side is Ramara and which is Orillia?

	East side of the Narrows	West side of the Narrows
Municipality	Township of Ramara (Atherley-Uptergrove settlement area)	City of Orillia
Lake frontage	Lake Simcoe to the south; Couchiching to the north	Lake Simcoe at the city's south end; Couchiching along most of the city
Conservation authority	Ramara is represented on the LSRCA board	Orillia is not an LSRCA member
Septic, where it exists	Ramara's mandatory re-inspection within 100 m of the Lake Simcoe shoreline	Orillia inspects every private system every five years
County	Part of Simcoe County, so the tax bill includes a county portion	Separated city, no county portion

Atherley is one of Ramara's nine settlement areas, grouped with Uptergrove. Driving south from the bridge on Highway 12 takes you down Ramara's shore: Mara Provincial Park is about 10 minutes south of Orillia, and the Brechin and Ramara shore guide picks up from there.

On the city side, Orillia's south end reaches Lake Simcoe west of the Narrows. Local paddling guides list Collins Drive (425 Collins Drive), along with Portage Bay on Couchiching Point Road and Atherley Community Park, as launch points for a 13 km loop through the Narrows.

Why does the municipality matter so much here?

Because the rules on either side of the bridge really are different.

Shoreline approvals. Ramara is represented on the board of the Lake Simcoe Region Conservation Authority, and LSRCA approvals can apply to work near the water there. Orillia is not a member. A September 2024 Orillia council preview described the City as "the only municipality on Lake Simcoe which is not a member of the LSRCA," and noted that it works with the authority and has built many similar protections into its own Official Plan and zoning by-law. On a city lot, your first call about shoreline work is the City; on a Ramara lot, it is the Township and LSRCA. See Lake Simcoe shoreline rules and docks, boathouses and permits.

Septic. Most of Orillia is on city sewer, and any private system in the city must be inspected every five years. Buyers and lenders can ask for a septic compliance letter. In Ramara, a lot within 100 metres of the Lake Simcoe shoreline is in the Township's re-inspection program, with a pump-out certificate due in the inspection year and $30 a year on the tax bill. The full comparison is on rossmanteam.com's septic inspection programs guide.

Taxes. Orillia's rate and Ramara's rate are set separately, and Ramara's includes a Simcoe County portion. The current rates are on the Orillia and Ramara area pages.

What is boating through the Narrows like?

Busy, narrow and worth taking slowly. Local paddling guides warn that traffic can be heavy on weekends, especially through the Narrows, and recommend that stand-up paddleboarders avoid the Narrows entirely. There are marinas along the Narrows itself, so expect boats coming and going from slips as well as passing through.

Parks Canada's Trent-Severn navigation data gives the numbers that matter for planning:

Point on the waterway	Distance from Trenton	Note
Lake Simcoe entrance (Talbot River side)	293.2 km	Lock 41 – Gamebridge is just upstream
Atherley Narrows Bridge	318.0 km	Clearance 7.0 m (22.8 ft) at normal levels
CN swing bridge near the Narrows	318.1 km	Railway bridge just beside the highway bridge
Lock 42 – Couchiching	337.8 km	Near Washago; leads to the Severn River

So from the Narrows it is roughly 20 km north to Lock 42 and the Severn River, and roughly 25 km along the waterway route across Lake Simcoe to the Talbot River entrance. Parks Canada notes that bridge clearances are based on normal navigation-season levels and can change with the water. In a high-water spring, check before you take a tall boat or a boat with a raised arch under the bridge.

A home near the Narrows puts you within easy reach of both lakes: the open water of Simcoe to the south and the more sheltered Couchiching to the north. For routes, launches and wind on the big lake, see boating on Lake Simcoe. For Couchiching itself, our sister site lakecouchichinghomes.com goes shoreline by shoreline.

What about winter at the Narrows?

Moving water keeps ice weaker. The current through the Narrows means ice here can stay thin or open long after the bays are frozen, and you should never judge it by what the rest of the lake is doing. Ramara's own spring 2026 flood notice told residents to treat all ice on waterbodies as unsafe during the thaw. See ice fishing and winter on Lake Simcoe for ice-safety sources and what to ask about winter access.

What should buyers watch for near the Narrows?

Low-lying land. Property close to either lake at this end can feel high water, and spring 2026 brought shoreline flooding to low-lying areas around Lake Simcoe. Ask the seller directly what happened that spring, and look for a sump pump and backwater valve.

Which lake, exactly. Some streets near the Narrows have homes on Simcoe and homes on Couchiching within a short walk of each other. The listing's water body label is the seller's description; look at the survey and a map.

Boat traffic and noise. Being near the channel is convenient, but it also means a steady flow of boats in summer. Visit on a July weekend if you can.

The historic site. Because parts of the Narrows lakebed are a National Historic Site, in-water work close to the channel is a conversation to have with Parks Canada early, not after you have hired a contractor.

Dock depth. Parks Canada lowers both lakes every fall. Check how the water sits at the dock in late season, not only in June. What drives Simcoe prices covers how depth and bottom type affect value.

How Jordan can help

Jordan Rossman is a REALTOR® with Real Broker Ontario Ltd., Brokerage, with an office on Mississaga Street in downtown Orillia and in local real estate since 2014. Near the Narrows, he can help you confirm which municipality and which lake a property is really on, and line up the right permit, septic and boating questions for that side of the bridge. Call 705-345-0797 to talk it through.