River flows were very low, with few flood events,
declining water storages and drying wetlands. 

National river inflows remained below average at 66 mm or 504,000 GL; 27% below the 2000–2019 average but 26% more than the previous year.

Very to extremely low river flows occurred in several catchments in the Top End and Capricornia.

River flows above average across much of NSW and in the Nullarbor catchments. There were no algal blooms in the Murray-Darling Basin.

Major floods occurred on the southern NS coast in August. The Shoalhaven River and surrounding areas experienced the highest flood levels since 1991.

Very intense rainfall caused flash flooding in southeast Queensland in January and again in December.

Rank of annual streamflow by catchment
Rank of annual streamflow by catchment

Storage in the Murray-Darling storages increased, with combined storage in the five largest storages increasing from 35% to 57% of capacity, reaching levels last seen in 2018.

Reservoir storage in the Ord system in the Kimberly region declined for a third year, from 34% to 29% of capacity.

Urban water supplies increased for all cities. The Sydney and Canberra supply systems increased from around half to near full capacity. Smaller improvements occurred in Melbourne (+12%) and Adelaide (+7%) whereas supplies for Brisbane and Perth remained stable.

The national extent of wetland flooding increased by 8% on 2019 but remained at similarly low levels as the previous two years. Total inundation was 21% below the 2000–2019 average.

Wetland extent was the lowest since at least 2000 in the Ord, Murchison and Albany catchments in WA as well as several catchments in eastern Victoria.

The greatest wetland extents were observed in several smaller coastal catchments in southwest WA, along the East coast and in western Tasmania, 

Annual inundated area
National annual inundated area