The Todd River (Arrernte: Lhere Mparntwe) is an ephemeral river in the southern Northern Territory, central Australia. The origins of the Todd River are in the MacDonnell Ranges, where it flows past the Telegraph Station, almost through the centre of Alice Springs, through Heavitree Gap at the southern end of Alice Springs and continuing on for some distance, passing through the western part of the Simpson Desert, as it becomes a tributary of the Hale River, and eventually flowing into Lake Eyre in South Australia. The indigenous Arrernte people know this river as Lhere Mparntwe (pronounced ler-ra m-barn-twa). The Todd is in a very arid part of Australia and has zero to very low flow during 95% of the year. When it does flow, it carries a heavy sediment load picked up from the grazing land around the Bond Springs homestead which lends its waters a milky chocolate colour and renders them completely opaque. The Todd River's English name, and that of its tributary, the Charles River, were given by surveyor W. W. Mills, after Charles Todd, then South Australian Superintendent of Telegraphs and Postmaster General of South Australia, who was largely responsible for the construction of the Overland Telegraph Line. Significance to Alice Springs The Todd River is integral to the city of Alice Springs, which has its central business district built on the edge of the river. A large portion of the Alice Springs municipal area is situated on a flood plain of the Todd River, created by flooding upstream of the east-west barrier created by the Heavitree Range, a local segment of the MacDonnell Ranges. The Todd runs south through this range at Heavitree Gap along with the main road and rail links connecting Alice Springs to Adelaide. Heavy flows of the Todd can cut road and rail access, and the bottle neck effect of the Gap can cause flooding in many parts of the town. There have been numerous cases of people drowning as often people camp in the riverbed and the flooding can occur very rapidly and unexpectedly from heavy rains upstream. Heavy rainfalls in the catchment to the north of Alice Springs cause the river to start flowing through the town around 6 to 8 hours later. The river can change from its normal dry bed to a bank-to-bank flow within 15 minutes, and it is possible to follow the leading edge of the