Reservoir · Tasmania · Australia · BOM Water Data Online
Lake Rowallan
93.5% full
Capacity
130.5 hm³
Volume stored
122 hm³
River
Mersey Forth
Year completed
1967
Coordinates
41.775°S, 146.211°E
Last updated
2026-10-25
Current fill
93.5%vs 7 days ago
+1.7 ppgaining
vs 1 year ago
-2.0 ppyear-over-year
7-day trend
↑rising
Drought context
Storage vs October average
103%of normal
93.5% full on 2026-10-25, against an average of 91.1% for October across 4 years of readings (+2.4 points).
Rain over the last three months · 11 October 2026
Moderately dry
In the three months to 11 October 2026 the area around Lake Rowallan had well below normal rain, a shortfall seen about one year in six. Rainfall compared with the long-run record for the same season at this point (Copernicus Global Drought Observatory, SPI-3 index −1.28). 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: 2026-10-25.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 41.775°S, 146.211°E · Open in Google Maps
About Lake Rowallan
As of October 25, 2026, Lake Rowallan is filled to 93.5% of its total capacity, holding 122 hm³ of water out of a maximum 130.5 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has risen by 1.7 percentage points, and it is 2.0 points below its level on the same date a year earlier.
Across the readings we hold for Lake Rowallan — 1094 data points between October 28, 2023 and October 25, 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 October 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
- 93.5% of total capacity
- Water stored
- 122 hm³
- Total capacity
- 130.5 hm³
- 7-day change
- ▲ 1.7 pp
- Year-on-year
- ▼ 2.0 pp
- 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 25, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 25 Oct 2026 | 93.5% | 122 |
| 24 Oct 2026 | 93.4% | 121.91 |
| 23 Oct 2026 | 93.4% | 121.88 |
| 22 Oct 2026 | 93.3% | 121.78 |
| 21 Oct 2026 | 93.2% | 121.58 |
| 20 Oct 2026 | 92.8% | 121.15 |
| 19 Oct 2026 | 92.4% | 120.54 |
| 18 Oct 2026 | 91.8% | 119.76 |
| 17 Oct 2026 | 91.0% | 118.78 |
| 16 Oct 2026 | 90.1% | 117.53 |
| 15 Oct 2026 | 88.9% | 115.98 |
| 14 Oct 2026 | 87.5% | 114.24 |