Reservoir · Tasmania · Australia · BOM Water Data Online
Lake St Clair
1.1% full
Capacity
2,000 hm³
Volume stored
22 hm³
River
Derwent River
Year completed
1968
Coordinates
42.068°S, 146.168°E
Last updated
2026-09-07
Current fill
1.1%vs 7 days ago
+0.3%gaining
vs 1 year ago
-0.1%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. -42.068, 146.168 · Open in Google Maps
About Lake St Clair
As of September 7, 2026, Lake St Clair is filled to 1.1% of its total capacity, holding roughly 22 hm³ of water out of a maximum 2,000 hm³. At this level the reservoir is critically low. Of that total, about 206 hm³ is usable (live) storage.
Over the most recent week on record the fill level has held broadly steady (+0.3 pts), and it sits close to where it was a year earlier.
Across the readings we hold for Lake St Clair — 1093 data points between September 11, 2023 and September 7, 2026 — the level has ranged from a low of 0.1% (March 1, 2025) to a high of 2.4% (September 2, 2024). On average the reservoir is fullest around September and at its lowest around March.
The dam at Lake St Clair was completed in 1968. It is operated by BOM primarily for water supply. It lies within the Derwent River Basin basin at 42.068°S, 146.168°E.
Key facts
- Current fill level
- 1.1%
- Water stored
- 22 hm³
- Total capacity
- 2,000 hm³
- Usable capacity
- 206 hm³
- 7-day change
- ▲ 0.3 pts
- Year-on-year
- ▼ 0.1 pts
- Primary use
- Water supply
- River
- Derwent River
- River basin
- Derwent River Basin
- Year completed
- 1968
- Operator
- BOM
- Coordinates
- 42.068°S, 146.168°E
- Last updated
- September 7, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 7 Sep 2026 | 1.1% | 22 |
| 6 Sep 2026 | 1.1% | 22 |
| 5 Sep 2026 | 1.0% | 21 |
| 4 Sep 2026 | 1.0% | 20 |
| 3 Sep 2026 | 0.9% | 18 |
| 2 Sep 2026 | 0.8% | 16 |
| 1 Sep 2026 | 0.8% | 16 |
| 31 Aug 2026 | 0.8% | 16 |
| 30 Aug 2026 | 0.9% | 17 |
| 29 Aug 2026 | 0.9% | 18 |
| 28 Aug 2026 | 0.9% | 18 |
| 27 Aug 2026 | 0.9% | 19 |