 Peak flow for the Elizabeth River occurs in February with 389Ml/day, after which it slowly decreases until July when there is no freshwater input into Darwin Harbour until the onset of the following wet season (Padovan 1997).Cyclone frequency is low to moderate.The Finniss, Elzabeth and Howard Rivers have a mean annual outflow of ,

The water quality at the upper estuary monitoring sites of the Northern Territory Government was 2011 in excellent condition.