Queensland emergency services are stocking up on anti-venom medication after reports of snakes in flood-bound St George in the state's southwest.

Floodwaters are slowly falling but the Department of Community Safety says snakes trying to find dry ground are prevalent.

Up to 20 homes remain flooded at St George and roads continue to be cut off.

Floodwaters are dropping at Roma and Charleville, but further south the border towns of Dirranbandi, Hungerford and Hebel are bracing for river levels to peak.