A recent article from scientists at the University of Georgia investigated the survival of avian influenza virus in water. 

Viability is affected by pH, but with values of 7.4 to 8.2 supporting survival. A low temperature (approximately 50 F) and low to moderate salinity also extended the time over which viruses retained infectivity. The results of this study are important in understanding the transmission of avian influenza from free living water fowl to commercial flocks.