I dropped a camera in the water in the factory where I work; the micro SD card in the camera had private pictures on int that I don't want anyone to see. Knowing that the water contained some chemicals (industrial flocculants), is it likely that the card will still be readable after a year?
Flash memory like SD and Micro SD cards is very robust, and flocculants in the water aren't likely to damage either the plastic housing of the card or the electronics. If the contact strips (often gold plated, on better quality memory cards) aren't too corroded to make contact, it's very likely that someone who really cares and is willing to expend a little effort will be able to just plug the card into a card reader and read out its contents.
Even if the card is physically broken, it's almost certain that someone who has reason to want to can connect the actual chip(s) inside to a new connector and read the content.
I suspect yes, images will be recoverable IF someone actually finds the card. What are the odds? I guess OP is in best position to guestimate that.
Water: Coating will likely protect the card, contacts are gold plated. If we need to access NAND on micro SD cards for purpose of data recovery, removing coatings requires quite some mechanical force (English not my native language, do not know how else to put this). I use a fiber glass pen, sanding is an option too and some labs use lasers.
Time factor: NAND flash memory 'bleeds' data and given enough time card will become unreadable. But even if card is unreadable by ordinary user, a lab may be able to recover the data. Or better said, anyone who owns one of these + accompanying software :
But eventually your images will 'fade away'. The cheaper the card the quicker. The higher ambient temperature, the quicker. The more use a card saw, the quicker. I have seen those dead cheap promotional flash drives that started 'flipping bits' in a matter of months.
Last year, I found a camera and memory cards on a nearby hill, that had been out in four or five wet Scottish winters (west coast). The SD card that was in the camera was the most damaged, with severe corrosion of the contacts, but a painting a little conductive ink onto the pads enabled the data to be read with no trouble. That enabled me to identify the owner and return their property (not that the camera was much use any more, but the pictures were welcomed back).
When making the repair, I found that it's best to remove the plastic housing before painting the pads, as this makes it easier to avoid or correct any bridging you might inadvertently cause.