Yan Yean Reservoir

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.

Aerial image of Yan Yean Reservoir
  • 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 poster for more information, or learn more about Melbourne’s water supply history.

Water catchment protection and access

Yan Yean Reservoir is an on-stream reservoir, filled by rivers or rainfall that runs off the nearby forested water catchments. There is:

  • no entry into the water supply catchment area, with offenders subject to prosecution under the Water Act 1989 (Vic)
  • entry permitted along public access roads including Yan Yean Reservoir Park, managed by Parks Victoria.

Ridge Road runs through the catchment.

Melbourne Water continually reviews our protected catchments to determine if more areas can be opened to the public. While this would allow more people to enjoy Victoria’s vast natural spaces, it must be balanced with protecting our precious drinking water for the safety of our community.

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 (1856-2022)

Graph of annual rainfall (mm) at Yan Yean Reservoir, 1856-2022

Monthly rainfall records (mm)

Last updated: January 2023

Month Wettest Driest Average
​January 144.1 (1872) 0.0 (1878) 45.4
February​ 221.0 (1911) 0.0 (1991) 45.6
March​ 193.3 (1970) 2.5 (1948) 50.7
April​ 215.1 (1901) 0.0 (1923) 57.6
May​ 147.8 (1942) 2.3 (1934) 56.5
June​ 166.8 (1977) 11.7 (1972) 52.6
July​ 146.8 (1891) 15.4 (1979) 50.5
August​ 151.1 (1939) 10.9 (1928) 58.7
September​ 231.9 (1916) 9.9 (1938) 62.1
October​ 195.6 (1934) 7.4 (1914) 68.4
November​ 207.2 (1988) 5.6 (1967) 62.5
December​ 211.8 (1930) 2.8 (1972) 56.7
Annual total 1050.9 (1872) 370.6 (1945) 667.3
Last updated: