Climate and water
- Annual rainfall was similar to the average in 2013–14 and 2014–15, above average in 2015–16, and below average in 2016–17.
- High rainfall in September 2013, June 2016 and September 2016 contributed to well above-average streamflow during these months.
- Rainfall totals for June and September 2016 were both the second highest on record for these months, while 2017 brought the driest June on record to more than 50% of the region.
For further information on the region's climate and water conditions during the 2016–17 year scroll down this page or click on the links below:
About the region
- The Canberra region has a relatively dry, continental climate with warm to hot summers and cool to cold winters. Rainfall in the region is relatively uniform throughout the year with a long-term monthly average of 50–75 mm.
- The main rivers in the region are the Molonglo, Cotter and Queanbeyan rivers, which all contribute to the Murrumbidgee River. Higher streamflows typically occur during winter and spring, following higher runoff from partially saturated catchments in autumn and winter. Streamflows in the Murrumbidgee River can also be influenced by water diversions from the Snowy Mountains Scheme.
Climate conditions
Rainfall
Figure C1 Annual rainfall deciles for the Canberra region during the 2013–2017 period
- Total area-averaged rainfall was similar to the long-term average of 787 mm for the 2013–14 and 2014–15 years, above average in 2015–16, and below average in 2016–17.
- Most of the region experienced average rainfall for all four years, however the southeastern part of the region (mainly in the Queanbeyan River catchment) received above-average rainfall in 2014–15 and 2015–16.
- Rainfall was below average for the western part of the region over the 2014–15 year.
Figure C2 Total monthly rainfall for the Canberra region during the 2013–2017 period compared with the long-term average and percentiles for the region
- An east coast low event in June 2016 caused the second highest June rainfall total on record for the region. This brought annual rainfall for 2015–16 to above average levels, despite below-average rainfall for eight months of the year.
- Despite very high rainfall in September 2016 (the second highest September total on record), 2016–17 rainfall was below average.
- Very dry conditions occurred in June 2017, with more than 50% of the region recording its driest June on record.
Actual evapotranspiration
Figure C3 Annual actual evapotranspiration deciles for the Canberra region during the 2013–2017 period
- Total area-averaged actual evapotranspiration was slightly above the long-term average value of 642 mm for all four years.
- For most of the region, annual actual evapotranspiration was in the average range for all of the four-year period.
- Above average evapotranspiration occurred mostly in the south-eastern corner of the region (the Queanbeyan River catchment) in 2014–15 and 2015–16, and in the northern part of the region in 2016–17.
Figure C4 Total monthly actual evapotranspiration for the Canberra region during the 2013–2017 period compared with the long-term average and percentiles for the region
- For most of the four-year period, total area-averaged actual evapotranspiration was close to the long-term average.
- Above-average actual evapotranspiration was generally observed in the spring and summer months corresponding to above-average temperatures (e.g. December 2014–February 2015, February 2016).
- High actual evapotranspiration for some months was also likely due to increased water availability from high rainfall events in preceding months (e.g. in October–November 2016 following very high rainfall in September 2016).
Soil moisture
Figure C5 Annual soil moisture deciles for the Canberra region over the 2013–2017 period
- Soil moisture in the root zone (0–1 m depth) was average across most of the region for 2013–14, 2014–15 and 2015–16. It was above average for most of the region during 2016–17.
- Rainfall and soil moisture are typically closely aligned. For example, annual soil moisture deciles for 2013–14, 2014–15, and 2015–16 roughly correspond to the rainfall deciles for those years.
- Despite mostly average rainfall, soil moisture for 2016–17 was above average for most of the region. This is likely due to the cumulative effect of high rainfall in June and September 2016.
Streamflow responses
Figure C6 Key flow gauging stations along the main rivers within the Canberra region
- The Cotter and Queanbeyan rivers contribute most of the inflows to the storages in the Canberra region.
- Molonglo River, one of the major tributaries of the Murrumbidgee River, runs through the Canberra city centre where it is dammed to form Lake Burley Griffin.
Figure C7 Total monthly flow for key rivers during the 2013–2017 period compared with long-term average and percentiles
- Streamflow in the Cotter and Molonglo rivers was generally below average for most of the four-year period. Flows in the Queanbeyan River were comparatively higher, especially during 2014–15 and 2015–16, mostly due to comparatively higher rainfall in the southeastern part of the region.
- Most of the annual streamflow for 2016–17 occurred during September–October 2016. The well above-average streamflow during this 2-month period was due to heavy rainfall during September 2016 across the entire region.
- Well above-average streamflows in July 2016 followed high rainfall in June 2016, caused by an east coast low event.
- Well above-average streamflows were also observed in the Molonglo and Queanbeyan rivers in September 2013, due to high rainfall in that month.
- There was little streamflow response following the above-average rainfall in March 2017, which can be attributed to the relatively low soil moisture conditions across the region following a very dry summer.