re: Tax write offs for people who flooded?

You're simply using the purchases, whether in 2016 or 2017, to approximate what your loss was in August of 2016. If you had flood insurance, you may be able to get a better idea of what your loss was from the insurance adjusters report. Either way, the goal is find a good way to approximate the decline in fair market value if your house and personal property. Something else to consider...if the fridge you lost was 5 years old, the value of a new one wouldn't necessarily approximate your loss of the old one. You'd want to factor in depreciation.