Reservoir · Tasmania · Australia · BOM Water Data Online
Lake Cethana
7.1% full
Capacity
112.2 hm³
Volume stored
8 hm³
River
Forth River
Year completed
1971
Coordinates
41.509°S, 146.133°E
Last updated
2026-06-09
Current fill
7.1%vs 7 days ago
-0.4%losing
vs 1 year ago
-6.4%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: 2026-06-09.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. -41.509, 146.133 · Open in Google Maps
About Lake Cethana
As of June 9, 2026, Lake Cethana is filled to 7.1% of its total capacity, holding roughly 8 hm³ of water out of a maximum 112 hm³. At this level the reservoir is critically low. Of that total, about 48 hm³ is usable (live) storage.
Over the most recent week on record the fill level has held broadly steady (-0.4 pts), and it is 6.4 points below its level on the same date a year earlier.
Across the readings we hold for Lake Cethana — 1094 data points between June 12, 2023 and June 9, 2026 — the level has ranged from a low of 0.6% (March 29, 2025) to a high of 29.7% (September 2, 2024). On average the reservoir is fullest around September and at its lowest around January.
The dam at Lake Cethana was completed in 1971. It is operated by BOM primarily for water supply. It lies within the Forth River Basin basin at 41.509°S, 146.133°E.
Key facts
- Current fill level
- 7.1%
- Water stored
- 8 hm³
- Total capacity
- 112 hm³
- Usable capacity
- 48 hm³
- 7-day change
- ▼ 0.4 pts
- Year-on-year
- ▼ 6.4 pts
- Primary use
- Water supply
- River
- Forth River
- River basin
- Forth River Basin
- Year completed
- 1971
- Operator
- BOM
- Coordinates
- 41.509°S, 146.133°E
- Last updated
- June 9, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 9 Jun 2026 | 7.1% | 8 |
| 8 Jun 2026 | 7.5% | 8 |
| 7 Jun 2026 | 6.7% | 8 |
| 6 Jun 2026 | 5.2% | 6 |
| 5 Jun 2026 | 5.9% | 7 |
| 4 Jun 2026 | 5.0% | 6 |
| 3 Jun 2026 | 7.0% | 8 |
| 2 Jun 2026 | 6.1% | 7 |
| 1 Jun 2026 | 9.4% | 11 |
| 31 May 2026 | 8.0% | 9 |
| 30 May 2026 | 6.7% | 7 |
| 29 May 2026 | 5.5% | 6 |
Frequently asked questions
What is the current water level of Lake Cethana?
As of June 9, 2026, Lake Cethana is at 7.1% of its capacity, holding approximately 8 hm³ of water, according to BOM data.
Is Lake Cethana reservoir full?
No. As of June 9, 2026, Lake Cethana is critically low at 7.1% of its capacity, so it is not full.
Is the water level at Lake Cethana rising or falling?
The level at Lake Cethana has been broadly stable over the latest week on record (-0.4 points).
How much water can Lake Cethana hold?
Lake Cethana has a total capacity of 112 hm³, of which about 48 hm³ is usable storage.
Where is Lake Cethana reservoir located?
Lake Cethana is located in Tasmania, Australia, within the Forth River Basin basin (coordinates 41.509°S, 146.133°E).
When was Lake Cethana dam built?
The dam at Lake Cethana was completed in 1971.
What is Lake Cethana used for?
Lake Cethana is used primarily for water supply, and is managed by BOM.