Reservoir · Western Australia · Australia · BOM Water Data Online
Mundaring
42.3% full
Capacity
63.6 hm³
Volume stored
27 hm³
River
Helena River
Year completed
1902
Coordinates
31.987°S, 116.214°E
Last updated
2026-09-07
Current fill
42.3%vs 7 days ago
+0.2%gaining
vs 1 year ago
-8.6%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: 2026-09-07.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. -31.987, 116.214 · Open in Google Maps
About Mundaring
As of September 7, 2026, Mundaring is filled to 42.3% of its total capacity, holding roughly 27 hm³ of water out of a maximum 64 hm³. At this level the reservoir is within its normal operating range. Of that total, about 57 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 8.6 points below its level on the same date a year earlier.
Across the readings we hold for Mundaring — 1058 data points between September 11, 2023 and September 7, 2026 — the level has ranged from a low of 33.2% (May 22, 2025) to a high of 66.1% (September 17, 2023). On average the reservoir is fullest around October and at its lowest around May.
The dam at Mundaring was completed in 1902. It is operated by BOM primarily for water supply. It lies within the Helena River Basin basin at 31.987°S, 116.214°E.
Key facts
- Current fill level
- 42.3%
- Water stored
- 27 hm³
- Total capacity
- 64 hm³
- Usable capacity
- 57 hm³
- 7-day change
- ▲ 0.2 pts
- Year-on-year
- ▼ 8.6 pts
- Primary use
- Water supply
- River
- Helena River
- River basin
- Helena River Basin
- Year completed
- 1902
- Operator
- BOM
- Coordinates
- 31.987°S, 116.214°E
- Last updated
- September 7, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 7 Sep 2026 | 42.3% | 27 |
| 6 Sep 2026 | 42.2% | 27 |
| 5 Sep 2026 | 42.2% | 27 |
| 4 Sep 2026 | 42.1% | 27 |
| 3 Sep 2026 | 42.1% | 27 |
| 2 Sep 2026 | 42.1% | 27 |
| 1 Sep 2026 | 42.1% | 27 |
| 31 Aug 2026 | 42.1% | 27 |
| 30 Aug 2026 | 42.0% | 27 |
| 29 Aug 2026 | 42.0% | 27 |
| 28 Aug 2026 | 42.0% | 27 |
| 27 Aug 2026 | 41.9% | 27 |