Dam levels
We need steady, regular rain in order to soak our catchments and get water flowing into our dams. Slowly declining rainfall means Perth's dams receive much less streamflow than in past years. Streamflow is the amount of water entering our dams from our catchments and is measured by changing water storage volumes.
The water in our dams is no longer made up of just streamflow from rain. Groundwater and desalinated water are stored in these dams during periods of low demand so it is available when it is most needed in the hotter months.
Our water overview
Updated: Tuesday, 16 January 2024
Learn more about how this data is updated
798 ML
Used yesterday
To 9am
0.00
mm
May total
May average*
32.20
mm
88.70
mm
Current
42.5%
268 GL
Last year
45%
284 GL
Change
5.7%
-16.2 GL
* Average monthly rainfall (for the period 1876 - 2016).
Dam volumes, rainfall and water use data is updated every working day, streamflow is updated weekly.
Total dam levels
Total Dam Capacity
Perth Metro
48%
302.56 GL
Last year
57%
359.2 GL
Change
-15.8%
-56.65 GL
Total Dam Capacity
South West
46.5%
168.24 GL
Last year
62.2%
225.18 GL
Change
-25.3%
-56.94 GL
Total Dam Capacity
Great Southern
3.8%
2.12 GL
Last year
4.4%
2.47 GL
Change
-14.2%
-0.35 GL
Total Dam Capacity
Total Dam Capacity
North West
87.7%
9498.41 GL
Last year
86.6%
9379.9 GL
Change
1.3%
118.51 GL
Dam storage for the last 14 days - metro supply
| Year | Today | 18/01 | 17/01 | 16/01 | 15/01 | 14/01 | 13/01 | 12/01 | 11/01 | 10/01 | 09/01 | 08/01 | 07/01 | 06/01 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2024 | N/A | N/A | 302.6 | 303.0 | 303.7 | 304.5 | 304.8 | 305.8 | 306.4 | 306.9 | 307.8 | 309.1 | 309.3 | 309.8 |
| 2023 | 357.6 | 358.5 | 359.2 | 360.3 | 360.8 | N/A | N/A | N/A | N/A | N/A | 364.4 | 365.1 | N/A | N/A |
| Comparison | N/A | N/A | -56.6 | -57.3 | -57.1 | N/A | N/A | N/A | N/A | N/A | -56.7 | -56.0 | N/A | N/A |
N/A = Data not available. Storage measured in GL.
Monthly dam volume comparison - metro supply
Select each point to see average monthly dam volume.
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2024 | 307.62 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| 2023 | 357.45 | 340.74 | 323.79 | 316.17 | 312.66 | 314.41 | 325.04 | 341.36 | 351.42 | 351.22 | 336.91 | 320.84 |
| 2022 | 364.53 | 347.31 | 331.70 | 321.79 | 318.01 | 323.18 | 329.46 | 369.71 | 398.19 | 400.23 | 390.37 | 380.44 |
| 2021 | 293.55 | 282.85 | 274.70 | 267.34 | 267.16 | 272.42 | 383.92 | 296.25 | 361.34 | 384.66 | 396.15 | 399.82 |
| 2020 | 294.94 | 283.32 | 274.08 | 267.85 | 267.04 | 272.40 | 283.15 | 296.38 | 313.89 | 318.91 | 314.88 | 308.46 |
| 2019 | 333.65 | 317.65 | 303.57 | 291.21 | 283.69 | 281.77 | 291.51 | 302.77 | 325.42 | 326.26 | 318.98 | 306.35 |
| 2018 | 270.72 | 263.17 | 253.37 | 249.70 | 248.40 | 256.88 | 278.49 | 344.19 | 370.90 | 371.77 | 363.19 | 349.35 |
| 2017 | 197.74 | 194.59 | 189.45 | 186.42 | 185.27 | 188.32 | 197.48 | 238.72 | 270.02 | 285.20 | 282.51 | 277.58 |
N/A = Data not available. Storage measured in GL.
How climate change is impacting our water sources
Water sources for our largest scheme, the Integrated Water Supply Scheme (IWSS) which supplies Perth, the Goldfields and Agricultural Region and some parts of the South West have changed dramatically. Water for the IWSS is now comprised of a combination of sources, including desalinated seawater, groundwater, groundwater replenishment and streamflow into dams.
Traditionally, Perth relied heavily on streamflow into our dams as a water source, but declining streamflow has meant dams now play a bigger role as storage reservoirs. The water in our dams is no longer just made up of inflows from rain. Groundwater and desalinated water are stored in these dams during periods of low demand so it is available when it is most needed in the hotter months.
Perth's water sources at a glance
In 2022-23 the breakdown of Perth's water sources (IWSS) consisted of:
%
Desalination
%
Groundwater
%
Dams
%