CARAVAN TRIP 2007
The East Alligator River is approximately 160 kilometres long. After rising in the northern part of the Arnhem Land Plateau, it flows with tributary streams towards the northwest through magnificent canyons towards the Van Diemen Gulf which it meets at Point Farewell.
The South Alligator River is also about 160 kilometres long. It rises north of Mount Stow also on the Arnhem Land plateau. It flows northwesterly in a valley containing a number of disused uranium mines developed between 1955 and 1965. It also finishes in the Van Diemen Gulf of the Timor Sea.
The West Alligator River rises in the lowlands and is 80 kilometres long. The Wildman River also flows in the region. The river system has a number of spectacular waterfalls including the Jim Jim Falls on Jim Jim Creek and the Twin Falls on Twin Falls Creek.
The rivers have created the alluvial plains including the mangrove swamp in the past 20,000 years.
Waterfall - Kakadu National Park after rainLike much of northern Australia, the Alligator Rivers region has a monsoon climate. The dry season lasts between May and September while the wet season lasts between November and March. April and October are transitional periods between the two months. Annual rainfall at Jabiru is approximately 1540 mm with almost all of it falling during the wet season. During the wet season, the prevailing winds are westerly to north-westerly while they are easterly to south-easterly during the dry season.
The three Alligator Rivers are perennial rivers flowing even during the dry season as is the Wildman River. All of the tributaries dry up in places during that period. The land dries out, and the wildlife concentrates around the permanent water sources such as the rivers, springs, waterholes and billabongs. The duration of the dry period depends on the rainfall during the wet season. In a normal year, the tributaries will start flowing around the middle of December and finish at the end of June, but the flow will start in November and finish in August if the rainfall has been particularly heavy.
During the wet season, the savanna turns green, the wildlife spreads out, the bird life returns and the streams flood into adjacent lands turning them into swamps. The flood plains leave behind silt when they gradually dry up during the wet season.