New Moto Guzzi Door Mats Available Now
Another suggestion is to empty your dishwasher and put things you want to preserve in there -- it's generally watertight and firmly attached to a wall.
A tip, that I hope you won't need, but might come in handy. To prevent sewage back up into your home slip a bike inner tube into the sewer line through the cleanout trap and inflate it with 5 to 10 psi. You won't flow waste either way so until the flooding is over, and the tube is removed.