Lake Rowallan

As of September 7, 2026, Lake Rowallan is filled to 63.9% of its total capacity, holding roughly 83 hm³ of water out of a maximum 131 hm³. At this level the reservoir is within its normal operating range.

Over the most recent week on record the fill level has risen by 12.6 percentage points, and it is 12.3 points above its level on the same date a year earlier.

Across the readings we hold for Lake Rowallan — 1093 data points between September 11, 2023 and September 7, 2026 — the level has ranged from a low of 20.9% (June 14, 2025) to a high of 101.6% (September 2, 2024). On average the reservoir is fullest around December and at its lowest around June.

The dam at Lake Rowallan was completed in 1967. It is operated by BOM primarily for water supply. It lies within the Mersey Forth Basin basin at 41.775°S, 146.211°E.