Lock 20 — Lock 20 – Ashburnham

Lock 20 Ashburnham sits at the northeastern corner of Little Lake in Peterborough, Ontario, at kilometre 144.5 of the Trent-Severn Waterway. This slow-operating valve gate lock serves as the gateway between the broad open waters of Little Lake and the narrow canal cut that leads to the world-renowned Peterborough Lift Lock just 1.8 kilometres upstream. Set away from busy roads and flanked by Beavermead Park to the south and Rogers Cove to the west, Ashburnham is one of the quieter overnight stops within the city limits of a major Kawartha municipality — and one of the most convenient for provisioning.

Constructed between approximately 1896 and 1900 as part of the Ontario–Rice Lake division of the Trent Canal, Lock 20 was built to raise vessels 3.7 metres (12 feet) from the level of Little Lake into the artificial canal leading to the hydraulic lift lock. The lock site was originally the location of private homes, later converted to workshops and a maintenance yard for the canal construction crew. Parks Canada replaced the upper and lower lock gates during the winter of 2025–2026 to ensure continued safe operation. [VERIFY — Parks Canada: exact construction dates and original contractor]

Boaters will find tie-up space on both sides of the lower lock walls, with grassy areas, shade trees, and picnic tables alongside the mooring. The Trans Canada Trail crosses directly over the lock, providing walking and cycling access into Ashburnham Village in roughly ten minutes and to downtown Peterborough in about fifteen. Potable water is available at the lockstation but there is no shore power. On summer Wednesday and Saturday evenings, boaters moored here are treated to fireworks over Little Lake — a local highlight that makes this one of the more memorable overnight tie-ups on the entire waterway.

⚠ Report a Data Error on this page ↗

▼ Below Lock

▼ Below Lock

📍 GPS: 44.2995225°N, 78.3066252°W · [VERIFY — Parks Canada], Peterborough, Ontario, ON · Get Directions ↗ · Street View ↗

For navigation, use CHS Chart #2023 — this map is for reference only and should not be used for marine navigation.

Boater Orientation Notes:

• Lock 20 is on Little Lake within Peterborough — the East City / Ashburnham neighbourhood on Hunter St E (600—900 m walk) has restaurants, grocery, bakery, and cafes.
• Peterborough Marina is adjacent (Mile 89.4) — gas, diesel, repairs, haulout, 30/50 amp, WiFi. VHF 68.
• Canadian Canoe Museum (~1.5 km) is a must-visit — National Geographic “Best of the World 2024” pick. New waterfront facility opened May 2024.
• Peterborough Lift Lock (Lock 21, 1.5 km north via trail) is the world’s highest hydraulic lift lock — you will transit this lock next.
• Exercise normal urban awareness and secure valuables — some transient activity has been reported near Beavermead Park, especially in warmer months.

🛒 Grocery

🍴 Restaurants

🏛 Local Interests

🔧 Support & Services

Last Updated: March 18, 2026

This is where the excitement starts ramping up — you’re one lock below the Peterborough Lift Lock. Approach and lock itself are routine. HEADS UP FOR THE EXIT: as soon as you leave Lock 20 northbound, you’ve got two swing bridges ahead of you, neither tall enough to clear. Both have to open for you. The same lock operator that worked you through 20 generally operates one of them, and coordinates the other. Expect to wait — don’t be surprised if it takes some time to get both opened. Past the swing bridges, you continue ahead through a narrow channel. As soon as you come around the corner, the Peterborough Lift Lock comes into view. It’s one of the coolest exits on the system because you can see what’s ahead of you — the lift lock is a hell of a sight from below. Not much for amenities at Ashburnham itself. There’s some stuff within walking distance, but nothing I’d specifically recommend.

Weather data for navigation planning purposes only. Always check Environment and Climate Change Canada’s official marine forecast before making operational decisions. weather.gc.ca ↗