Yan Yean is Melbourne’s oldest reservoir. It receives water from catchments north of Melbourne, and supplies the northern suburbs – typically spanning Morang to Whittlesea.
Yan Yean Reservoir’s location makes it a strategic source of water for supplying Melbourne’s northern and western areas, which will experience significant population growth over the coming decades.
Key facts
The dam at Yan Yean Reservoir is an earthfill embankment, and was completed in 1857.
- Catchment area: 2,250 hectares (off stream storage)
- Surface area: 560 hectares
- Total capacity: 30,266 megalitres
- Dam height: 10 metres
- Dam length: 963 metres
Yan Yean Reservoir helped transform Melbourne into a modern metropolis, after its humble beginnings as a settlement along the Yarra River. Download our posters for more information, or learn more about Melbourne’s water supply history.
Rainfall over the years
View highlights from our historical rainfall data for Yan Yean Reservoir, including annual rainfall, monthly averages, and the wettest and driest years by month.
Live rainfall and water storage data
Get the latest information on each of our 10 major reservoirs, including daily water storage levels and hourly rainfall and river level data.
Annual rainfall at Yan Yean (1856-2021)
Monthly rainfall records (mm)
Last updated: January 2022
| Month | Wettest | Driest | Average |
|---|---|---|---|
| January | 144.1 (1872) | 0.0 (1878) | 45.1 |
| February | 221.0 (1911) | 0.0 (1991) | 45.8 |
| March | 193.3 (1970) | 2.5 (1948) | 50.6 |
| April | 215.1 (1901) | 0.0 (1923) | 57.3 |
| May | 147.8 (1942) | 2.3 (1934) | 56.7 |
| June | 166.8 (1977) | 11.7 (1972) | 52.6 |
| July | 146.8 (1891) | 15.4 (1979) | 59.5 |
| August | 151.1 (1939) | 10.9 (1928) | 58.5 |
| September | 231.9 (1916) | 9.9 (1938) | 62.0 |
| October | 195.6 (1934) | 7.4 (1914) | 67.7 |
| November | 207.2 (1988) | 5.6 (1967) | 62.3 |
| December | 211.8 (1930) | 2.8 (1972) | 56.6 |
| Annual total | 1050.9 (1872) | 370.6 (1945) | 665.6 |
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