Reservoir · Tasmania · Australia · BOM Water Data Online
Lake Rowallan
84.3% full
Capacity
130.5 hm³
Volume stored
110 hm³
River
Mersey Forth
Year completed
1967
Coordinates
41.775°S, 146.211°E
Last updated
2026-10-12
Current fill
84.3%vs 7 days ago
+4.2%gaining
vs 1 year ago
-13.6%year-over-year
7-day trend
↑rising
Drought context
Storage vs October average
96%of normal
84.3% full on 2026-10-12, against an average of 87.5% for October across 4 years of readings (-3.2 points).
Rain over the last three months · 21 September 2026
Near normal
In the three months to 21 September 2026 the area around Lake Rowallan had rain close to normal for the season. Rainfall compared with the long-run record for the same season at this point (Copernicus Global Drought Observatory, SPI-3 index −0.98). Rain, not storage. Australia drought figures →
Data source: Bureau of Meteorology — Water Data Online (KiWIS) — daily mean storage volume, quality-controlled. Capacity from the BOM Water Storages ArcGIS layer (total design capacity in ML). Last reading: 2026-10-12.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. -41.775, 146.211 · Open in Google Maps
About Lake Rowallan
As of October 12, 2026, Lake Rowallan is filled to 84.3% of its total capacity, holding roughly 110 hm³ of water out of a maximum 131 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has risen by 4.2 percentage points, and it is 13.6 points below its level on the same date a year earlier.
Across the readings we hold for Lake Rowallan — 1094 data points between October 15, 2023 and October 12, 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.
Key facts
- Current fill level
- 84.3%
- Water stored
- 110 hm³
- Total capacity
- 131 hm³
- 7-day change
- ▲ 4.2 pts
- Year-on-year
- ▼ 13.6 pts
- Primary use
- Water supply
- River
- Mersey Forth
- River basin
- Mersey Forth Basin
- Year completed
- 1967
- Operator
- BOM
- Coordinates
- 41.775°S, 146.211°E
- Last updated
- October 12, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 12 Oct 2026 | 84.3% | 110 |
| 11 Oct 2026 | 83.1% | 108 |
| 10 Oct 2026 | 82.6% | 108 |
| 9 Oct 2026 | 82.1% | 107 |
| 8 Oct 2026 | 81.6% | 106 |
| 7 Oct 2026 | 80.9% | 106 |
| 6 Oct 2026 | 80.4% | 105 |
| 5 Oct 2026 | 80.1% | 105 |
| 4 Oct 2026 | 79.8% | 104 |
| 3 Oct 2026 | 80.1% | 105 |
| 2 Oct 2026 | 80.1% | 105 |
| 1 Oct 2026 | 78.9% | 103 |