Reservoir · Tasmania · Australia · BOM Water Data Online
Lake Trevallyn
61.9% full
Capacity
12.3 hm³
Volume stored
8 hm³
River
South Esk River
Year completed
1955
Coordinates
41.445°S, 147.081°E
Last updated
2026-07-28
Current fill
61.9%vs 7 days ago
+0.2%gaining
vs 1 year ago
+7.8%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. -41.445, 147.081 · Open in Google Maps
About Lake Trevallyn
As of July 28, 2026, Lake Trevallyn is filled to 61.9% of its total capacity, holding roughly 8 hm³ of water out of a maximum 12 hm³. At this level the reservoir is within its normal operating range.
Over the most recent week on record the fill level has held broadly steady (+0.2 pts), and it is 7.8 points above its level on the same date a year earlier.
Across the readings we hold for Lake Trevallyn — 1095 data points between July 30, 2023 and July 28, 2026 — the level has ranged from a low of 6.2% (June 19, 2026) to a high of 94.5% (September 3, 2024). On average the reservoir is fullest around September and at its lowest around April.
The dam at Lake Trevallyn was completed in 1955. It is operated by BOM primarily for water supply. It lies within the South Esk River Basin basin at 41.445°S, 147.081°E.
Key facts
- Current fill level
- 61.9%
- Water stored
- 8 hm³
- Total capacity
- 12 hm³
- 7-day change
- ▲ 0.2 pts
- Year-on-year
- ▲ 7.8 pts
- Primary use
- Water supply
- River
- South Esk River
- River basin
- South Esk River Basin
- Year completed
- 1955
- Operator
- BOM
- Coordinates
- 41.445°S, 147.081°E
- Last updated
- July 28, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 28 Jul 2026 | 61.9% | 8 |
| 27 Jul 2026 | 61.7% | 8 |
| 26 Jul 2026 | 59.8% | 7 |
| 25 Jul 2026 | 62.2% | 8 |
| 24 Jul 2026 | 61.9% | 8 |
| 23 Jul 2026 | 60.8% | 8 |
| 22 Jul 2026 | 60.6% | 7 |
| 21 Jul 2026 | 57.8% | 7 |
| 20 Jul 2026 | 58.0% | 7 |
| 19 Jul 2026 | 60.1% | 7 |
| 18 Jul 2026 | 57.5% | 7 |
| 17 Jul 2026 | 56.2% | 7 |
Frequently asked questions
What is the current water level of Lake Trevallyn?
As of July 28, 2026, Lake Trevallyn is at 61.9% of its capacity, holding approximately 8 hm³ of water, according to BOM data.
Is Lake Trevallyn reservoir full?
No. As of July 28, 2026, Lake Trevallyn is within its normal operating range at 61.9% of its capacity, so it is not full.
Is the water level at Lake Trevallyn rising or falling?
The level at Lake Trevallyn has been broadly stable over the latest week on record (+0.2 points).
How much water can Lake Trevallyn hold?
Lake Trevallyn has a total capacity of 12 hm³.
Where is Lake Trevallyn reservoir located?
Lake Trevallyn is located in Tasmania, Australia, within the South Esk River Basin basin (coordinates 41.445°S, 147.081°E).
When was Lake Trevallyn dam built?
The dam at Lake Trevallyn was completed in 1955.
What is Lake Trevallyn used for?
Lake Trevallyn is used primarily for water supply, and is managed by BOM.