Reservoir · Tasmania · Australia · BOM Water Data Online
Great Lake
30.8% full
Capacity
3,156.6 hm³
Volume stored
971 hm³
Year completed
1967
Coordinates
41.884°S, 146.742°E
Last updated
2026-07-28
Current fill
30.8%vs 7 days ago
+0.2%gaining
vs 1 year ago
+4.6%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: 2026-07-28.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. -41.884, 146.742 · Open in Google Maps
About Great Lake
As of July 28, 2026, Great Lake is filled to 30.8% of its total capacity, holding roughly 971 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 (+0.2 pts), and it is 4.6 points above its level on the same date a year earlier.
Across the readings we hold for Great Lake — 1095 data points between July 30, 2023 and July 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.
Key facts
- Current fill level
- 30.8%
- Water stored
- 971 hm³
- Total capacity
- 3,157 hm³
- Usable capacity
- 3,116 hm³
- 7-day change
- ▲ 0.2 pts
- Year-on-year
- ▲ 4.6 pts
- Primary use
- Water supply
- Year completed
- 1967
- Operator
- BOM
- Coordinates
- 41.884°S, 146.742°E
- Last updated
- July 28, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 28 Jul 2026 | 30.8% | 971 |
| 27 Jul 2026 | 30.6% | 965 |
| 26 Jul 2026 | 30.5% | 964 |
| 25 Jul 2026 | 30.5% | 962 |
| 24 Jul 2026 | 30.4% | 961 |
| 23 Jul 2026 | 30.4% | 958 |
| 22 Jul 2026 | 30.2% | 953 |
| 21 Jul 2026 | 30.1% | 950 |
| 20 Jul 2026 | 30.0% | 948 |
| 19 Jul 2026 | 30.0% | 946 |
| 18 Jul 2026 | 29.9% | 944 |
| 17 Jul 2026 | 29.8% | 941 |
Frequently asked questions
What is the current water level of Great Lake?
As of July 28, 2026, Great Lake is at 30.8% of its capacity, holding approximately 971 hm³ of water, according to BOM data.
Is Great Lake reservoir full?
No. As of July 28, 2026, Great Lake is low at 30.8% of its capacity, so it is not full.
Is the water level at Great Lake rising or falling?
The level at Great Lake has been broadly stable over the latest week on record (+0.2 points).
How much water can Great Lake hold?
Great Lake has a total capacity of 3,157 hm³, of which about 3,116 hm³ is usable storage.
Where is Great Lake reservoir located?
Great Lake is located in Tasmania, Australia (coordinates 41.884°S, 146.742°E).
When was Great Lake dam built?
The dam at Great Lake was completed in 1967.
What is Great Lake used for?
Great Lake is used primarily for water supply, and is managed by BOM.