I hope this question is appropriate to this Stack.
My elderly mother lives alone in a townhouse with a basement, since my father passed about six months ago. This morning, the basement experienced mild flooding with unusual circumstances. Let me describe the basement as best I can, then the extent of the flooding, then ask the question.
The basement is perhaps 800-1000 square feet, wall to wall carpet of the sort one puts in the basement of a townhouse-- rugged, durable, not exactly for show. Three areas are not carpeted: a workshop area my father used, the furnace and boiler closet, and a utility closet. The former of those two areas had sump pumps installed.
Of importance later is this: My father was a packrat and the basement is filled with bookshelves, tool shelves, tool racks, and just outright waist-high piles of full cardboard boxes. And I do mean filled. There are foot paths one can navigate with care.
Per answer below I will try to describe the conditions more precisely:
The carpet is slightly under ten years old, newly installed by previous owners to motivate the sale
Basement was largely unused and most of the carpet has been covered by boxes. I don't know if that means it is clean because the boxes protected it, or dirty because the boxes have pressed into it.
Climate appropriate to far Chicago suburbs, fifteen miles from the lake, 250 feet higher elevation from the lake. Central air keeps the ground floor at 72 in the summer, perhaps a bit chillier than that in the basement, and no excessive moisture or other leaks observed in all that time.
The flooding was not severe. The pumps functioned mostly as expected, but at least at one point they were overwhelmed, and my mother (with hearing problems) did not hear the pumps or the moisture alert until hours later. Most of the water was confined to the truly unfinished areas with the sump pumps, and by the time I arrived it has mostly receded.
At least some of it has gotten under the carpet, however. Visibly this extends only a short distance into the carpeted area. I have since mopped and wet-vac'd up everything I could, and placed two residential sized floor blowers to start drying things out. (I considered cutting a hole in the carpet and running the exhaust of a wet-vac under the carpet, but the amount of stuff sitting on the floor would just pin the carpet down and impede airflow.)
Some hours later, though, I can see some of the cardboard boxes on the floor well outside (what I thought was) the affected area wicking up moisture into themselves. I am not quite sure what's going on here but I conjecture the carpet acted like a sponge or a wick, and distributed moisture horizontally which I did not perceive, and the weight of the (let's be honest) junk is pressing it out. I'm not sure that makes sense.
How long do we have to deal with this situation before mold and other associated problems set in? Surely not months, but weeks? Days? Hours?
It is not physically possible for me, my mother, or any reasonable fraction of family and friends to clear out that basement in short order. It cannot be done. A day long junk removal contract is the only way to deal with this in the short term.
A mild confounding factor is that my mother and I have been willing to let older relatives of my father's generation slowly (s-l-o-w-l-y) pick over the tools and other objects they want. I can and will drop the hammer and set a deadline on this if necessary, but I do not know what level of speed is required here. I also do not want to see a $2,000 problem (expected cost of removal service) to snowball into a $20,000 nightmare because we were trying to be nice to family members.
In addition to that I will take any advice that seems relevant. But the time frame is the biggest unknown that I have right now.