Reservoir · Victoria · Australia · Melbourne Water
O'Shannassy
93.2% full
Capacity
3.123 hm³
Volume stored
3 hm³
River
O'Shannassy River
Year completed
1928
Coordinates
37.673°S, 145.808°E
Last updated
2026-10-29
Current fill
93.2%vs 7 days ago
+11.9 ppgaining
vs 1 year ago
-8.9 ppyear-over-year
7-day trend
↑rising
Drought context
Storage vs October average
96%of normal
93.2% full on 2026-10-29, against an average of 97.4% for October across 4 years of readings (-4.2 points).
Rain over the last three months · 11 October 2026
Near normal
In the three months to 11 October 2026 the area around O'Shannassy had rain close to normal for the season. Rainfall compared with the long-run record for the same season at this point (Copernicus Global Drought Observatory, SPI-3 index −0.57). Rain, not storage. Australia drought figures →
Data source: Melbourne Water daily storage — reference capacity and stored volume. Earlier daily volumes in the chart are Bureau of Meteorology readings, recomputed against that capacity. Last reading: 2026-10-29.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 37.673°S, 145.808°E · Open in Google Maps
About O'Shannassy
As of October 29, 2026, O'Shannassy is filled to 93.2% of its total capacity, holding 2.91 hm³ of water out of a maximum 3.123 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has risen by 11.9 percentage points, and it is 8.9 points below its level on the same date a year earlier.
Across the readings we hold for O'Shannassy — 1064 data points between October 29, 2023 and October 29, 2026 — the level has ranged from a low of 50.6% (April 24, 2025) to a high of 105.0% (July 21, 2024). On average the reservoir is fullest around August and at its lowest around May.
The dam at O'Shannassy was completed in 1928. It is operated by Melbourne Water primarily for water supply. It lies within the O'Shannassy River Basin basin at 37.673°S, 145.808°E.
Key facts
- Current fill level
- 93.2% of total capacity
- Water stored
- 2.91 hm³
- Total capacity
- 3.123 hm³
- 7-day change
- ▲ 11.9 pp
- Year-on-year
- ▼ 8.9 pp
- Primary use
- Water supply
- River
- O'Shannassy River
- River basin
- O'Shannassy River Basin
- Year completed
- 1928
- Operator
- Melbourne Water
- Coordinates
- 37.673°S, 145.808°E
- Last updated
- October 29, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 29 Oct 2026 | 93.2% | 2.91 |
| 28 Oct 2026 | 93.6% | 2.923 |
| 27 Oct 2026 | 93.4% | 2.916 |
| 26 Oct 2026 | 91.2% | 2.848 |
| 25 Oct 2026 | 80.3% | 2.509 |
| 24 Oct 2026 | 79.3% | 2.477 |
| 23 Oct 2026 | 79.8% | 2.491 |
| 22 Oct 2026 | 81.3% | 2.54 |
| 21 Oct 2026 | 82.9% | 2.59 |
| 20 Oct 2026 | 84.2% | 2.63 |
| 19 Oct 2026 | 85.8% | 2.68 |
| 18 Oct 2026 | 87.1% | 2.72 |