Reservoir · Tasmania · Australia · BOM Water Data Online
Great Lake
34.0% full
Capacity
3,156.6 hm³
Volume stored
1074 hm³
Year completed
1967
Coordinates
41.884°S, 146.742°E
Last updated
2026-10-28
Current fill
34.0%vs 7 days ago
-0.2 pplosing
vs 1 year ago
-2.6 ppyear-over-year
7-day trend
→stable
Drought context
Storage vs October average
101%of normal
34.0% full on 2026-10-28, against an average of 33.6% for October across 4 years of readings (+0.4 points).
Rain over the last three months · 11 October 2026
Severely dry
In the three months to 11 October 2026 the area around Great Lake had far less rain than normal, a shortfall seen about one year in fifteen. Rainfall compared with the long-run record for the same season at this point (Copernicus Global Drought Observatory, SPI-3 index −1.86). 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: 2026-10-28.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 41.884°S, 146.742°E · Open in Google Maps
About Great Lake
As of October 28, 2026, Great Lake is filled to 34.0% of its total capacity, holding 1,074 hm³ of water out of a maximum 3,157 hm³. At this level the reservoir is low. Of that total, 3,116 hm³ is usable (live) storage.
Over the most recent week on record the fill level has held broadly steady (-0.2 pp), and it is 2.6 points below its level on the same date a year earlier.
Across the readings we hold for Great Lake — 1095 data points between October 30, 2023 and October 28, 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. It is at 41.884°S, 146.742°E.
Key facts
- Current fill level
- 34.0% of total capacity
- Water stored
- 1,074 hm³
- Total capacity
- 3,157 hm³
- Usable capacity
- 3,116 hm³
- 7-day change
- ▼ 0.2 pp
- Year-on-year
- ▼ 2.6 pp
- Primary use
- Water supply
- Year completed
- 1967
- Operator
- BOM
- Coordinates
- 41.884°S, 146.742°E
- Last updated
- October 28, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 28 Oct 2026 | 34.0% | 1,074 |
| 27 Oct 2026 | 34.0% | 1,075 |
| 26 Oct 2026 | 34.1% | 1,077 |
| 25 Oct 2026 | 34.1% | 1,076 |
| 24 Oct 2026 | 34.0% | 1,075 |
| 23 Oct 2026 | 34.1% | 1,076 |
| 22 Oct 2026 | 34.1% | 1,077 |
| 21 Oct 2026 | 34.2% | 1,078 |
| 20 Oct 2026 | 34.2% | 1,079 |
| 19 Oct 2026 | 34.2% | 1,080 |
| 18 Oct 2026 | 34.2% | 1,081 |
| 17 Oct 2026 | 34.2% | 1,080 |