Reservoir · Tasmania · Australia · BOM Water Data Online
Great Lake
34.1% full
Capacity
3,156.6 hm³
Volume stored
1077 hm³
Year completed
1967
Coordinates
41.884°S, 146.742°E
Last updated
2026-09-07
Current fill
34.1%vs 7 days ago
+0.5%gaining
vs 1 year ago
+2.5%year-over-year
7-day trend
→stable
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: 2026-09-07.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. -41.884, 146.742 · Open in Google Maps
About Great Lake
As of September 7, 2026, Great Lake is filled to 34.1% of its total capacity, holding roughly 1,077 hm³ of water out of a maximum 3,157 hm³. At this level the reservoir is low. Of that total, about 3,116 hm³ is usable (live) storage.
Over the most recent week on record the fill level has held broadly steady (+0.5 pts), and it is 2.5 points above its level on the same date a year earlier.
Across the readings we hold for Great Lake — 1094 data points between September 10, 2023 and September 7, 2026 — the level has ranged from a low of 17.9% (May 28, 2024) to a high of 37.2% (November 17, 2025). On average the reservoir is fullest around October and at its lowest around May.
The dam at Great Lake was completed in 1967. It is operated by BOM primarily for water supply.
Key facts
- Current fill level
- 34.1%
- Water stored
- 1,077 hm³
- Total capacity
- 3,157 hm³
- Usable capacity
- 3,116 hm³
- 7-day change
- ▲ 0.5 pts
- Year-on-year
- ▲ 2.5 pts
- Primary use
- Water supply
- Year completed
- 1967
- Operator
- BOM
- Coordinates
- 41.884°S, 146.742°E
- Last updated
- September 7, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 7 Sep 2026 | 34.1% | 1,077 |
| 6 Sep 2026 | 34.0% | 1,074 |
| 5 Sep 2026 | 33.9% | 1,070 |
| 4 Sep 2026 | 33.8% | 1,068 |
| 3 Sep 2026 | 33.8% | 1,067 |
| 2 Sep 2026 | 33.7% | 1,063 |
| 1 Sep 2026 | 33.6% | 1,061 |
| 31 Aug 2026 | 33.6% | 1,060 |
| 30 Aug 2026 | 33.5% | 1,059 |
| 29 Aug 2026 | 33.5% | 1,058 |
| 28 Aug 2026 | 33.4% | 1,055 |
| 27 Aug 2026 | 33.3% | 1,053 |