Fossils of giant kangaroos and 3 tonne wombats found in a Lancefield paddock are at risk of disappearing. Archaeologist Dr Joe Dortch, who led surveying teams at the Lancefield Swamp in 2004 and 2005, says the drought and many bores sunk by residents are lowering the water level and causing the fossils to deteriorate. About 70 per cent of residents' drinking water comes from bores. Three observation bores have dropped up to four metres since 2001, according to Southern Rural Water groundwater and river manager Craig Parker.