Lake Ontario’s level is regulated under Plan 2014 by the International Joint Commission’s Lake Ontario–St. Lawrence River Board, which sets outflow through the Moses-Saunders dam at Massena. There is no announced plan to hold the lake higher; outflows are adjusted weekly. The official word, and the Board’s own level forecasts, are at ijc.org/en/loslrb. The binational six-month forecast is published monthly in the USACE Monthly Bulletin of Great Lakes Water Levels.
Live and historical readings: NOAA CO-OPS station 9052000, Cape Vincent NY (about 3 miles from Carleton Island). Gauge updates every 6 minutes; this page re-checks automatically and refreshes its history and statistics every 6 hours. The “average” is computed from NOAA’s monthly means back to 1918, but weighted toward recent years (exponential decay, ~15-year half-life) so the Plan-2014 regulation era and current hydrology dominate; record high/low still use the all-time extremes. The projection follows the official forecast from the latest USACE monthly bulletin (the gold diamonds, with whiskers for its likely range), which this page picks up automatically each month. It starts from today’s reading, and any gap between today and the bulletin fades out over the next few months. Past the bulletin’s six months it eases back to this page’s own estimate: that seasonal average curve, shifted by today’s surplus over it, with the surplus relaxing back over time.
Dock geometry was measured on June 9, 2026 (gauge at 247.1 ft): the dock runs 50 ft from shore; at the end the water was 24″ below the deck (deck ≈ 249.1 ft IGLD85) with 6 ft of water (bottom ≈ 241.1 ft); the side boards reach 42″ (3.5 ft) down from the deck.