upwind side of the Great Dividing Range, winter would receive the most rainfall in the year, with areas in the southern Riverina (around Albury), having the wettest winters, while in the north rainfall patterns are fairly consistent throughout the year. Corowa, in the south eastern Riverina has an average rainfall of per year while mean annual rainfall at Hay is . Drought in 2006 saw the lowest ever recorded rainfall in towns such as Lockhart, Tarcutta and Narrandera. Riverina bioregion One method of classification of boundaries for the Riverina is the Interim Biogeographic Regionalisation for Australia that defines the bioregion as an area comprising , with biogeographic sub-regions covering each of the Lachlan, Murrumbidgee, Murray Fans, Victorian Riverina, Robinvale Plains, and Murray Scroll Belt. The New South Wales Parks and Wildlife Service has divided New South Wales into 17 distinct bioregions. Bioregions are quite large areas of land that capture a geophysical pattern which is linked to fauna and flora ecosystems. The Riverina bioregion is an area of land that comprises part of the larger Riverina area but also extends into Victoria. It has been defined by the New South Wales Parks and Wildlife Service as extending from Ivanhoe in the Murray Darling Depression Bioregion south to Bendigo, and from Narrandera in the east to Balranald in the west. 74.03% of the bioregion is in New South Wales, the remainder in Victoria. In another mapping the World Wildlife Fund has made this area part of the larger Southeast Australia temperate savanna ecoregion that covers the western plains of New South Wales. River channels in the region support River Red Gum (Eucalyptus camaldulensis) and River Cooba (Acacia stenophylla) communities. Nearby higher areas contain Black Box (Eucalyptus largiflorens) woodlands and a salt-tolerant grass, saltbush and daisy understorey. Yellow Box (Eucalyptus melliodora) and Grey Box (Eucalyptus microcarpa) occur along with Cypress Pine (Callitris glaucophylla) on areas rarely subjected to flooding. The area away from the rivers often consists of treeless plains, consisting of various saltbush (Atriplex) species, Cotton Bush (Maireana aphylla) and varieties of Danthonia and Austrostipa native grasslands. Significant mammals endemic to forests in the bioregion include various species of glider, such as Sugar Gliders (Petaurus breviceps), Feathertail Gliders (Acrobates pygmaeus) and Squirrel Gliders (Petaurus norfolcensis) as well as Koalas (Phascolarctos cinereus) A wide variety of birdlife makes its home in wetlands in the Riverina, including many migratory species. Competition from introduced