Reservoir · Australian Capital Territory · Australia · BOM Water Data Online
Cotter
100.0% full
Capacity
79.4 hm³
Volume stored
79 hm³
River
Cotter River
Year completed
1912
Coordinates
35.317°S, 148.929°E
Last updated
2026-10-26
Current fill
100.0%vs 7 days ago
0.0 ppstable
vs 1 year ago
0.0 ppyear-over-year
7-day trend
→stable
Drought context
Storage vs October average
100%of normal
100.0% full on 2026-10-26, against an average of 100.0% for October across 4 years of readings (0.0 points).
Rain over the last three months · 11 October 2026
Near normal
In the three months to 11 October 2026 the area around Cotter 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 −0.51). Rain, not storage. Australia drought figures →
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: 2026-10-26.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 35.317°S, 148.929°E · Open in Google Maps
About Cotter
As of October 26, 2026, Cotter is filled to 100.0% of its total capacity, holding 79.37 hm³ of water out of a maximum 79.4 hm³. At this level the reservoir is high. Of that total, 76.2 hm³ is usable (live) storage.
Over the most recent week on record the fill level has held broadly steady (+0.0 pp), and it sits close to where it was a year earlier.
Across the readings we hold for Cotter — 1095 data points between October 28, 2023 and October 26, 2026 — the level has ranged from a low of 97.2% (March 31, 2026) to a high of 100.0% (October 28, 2023). On average the reservoir is fullest around July and at its lowest around April.
The dam at Cotter was completed in 1912. It is operated by BOM primarily for water supply. It lies within the Cotter River Basin basin at 35.317°S, 148.929°E.
Key facts
- Current fill level
- 100.0% of total capacity
- Water stored
- 79.37 hm³
- Total capacity
- 79.4 hm³
- Usable capacity
- 76.2 hm³
- 7-day change
- No change
- Year-on-year
- No change
- Primary use
- Water supply
- River
- Cotter River
- River basin
- Cotter River Basin
- Year completed
- 1912
- Operator
- BOM
- Coordinates
- 35.317°S, 148.929°E
- Last updated
- October 26, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 26 Oct 2026 | 100.0% | 79.37 |
| 25 Oct 2026 | 100.0% | 79.37 |
| 24 Oct 2026 | 100.0% | 79.37 |
| 23 Oct 2026 | 100.0% | 79.37 |
| 22 Oct 2026 | 100.0% | 79.37 |
| 21 Oct 2026 | 100.0% | 79.37 |
| 20 Oct 2026 | 100.0% | 79.37 |
| 19 Oct 2026 | 100.0% | 79.37 |
| 18 Oct 2026 | 100.0% | 79.37 |
| 17 Oct 2026 | 100.0% | 79.37 |
| 16 Oct 2026 | 100.0% | 79.37 |
| 15 Oct 2026 | 100.0% | 79.37 |