Most of lower Canada has been getting pounded this last week just like we border dwellers. I agree with the hydraulic pressure. About the best thing you can do right now is get a fan down there blowing across the wet area. Thats what I do when it gets like that in mine and it works amazingly well be it a big or tiny fan. Just something to move the air so it will evaporate. Hydraulic pressure yes. My house has a 1995 keyed foundation sitting right on a huge ledge on top of a hill in the center of a big field. When it pours mightily, especially when the ground is frozen under neath I get it pissing right in next to the sewer drain. I did manage to plug that up with sealer but it still seeps in along the seams some. Just like a concrete boat sitting in the water. Interestingly mine never has leaked along any of the cracks just the keyed seam.
You didn't say if you had a drain installed outside. Before you go and have someone go digging one for some reason consider this. I have a full drain with a sump. I used to get flooding especailly in winter rains. My solution was to plug the damned thing up. It was a pain as it was a 4 inch drain with about 30 1" holes that needed corks to do the deed. I put that out there not as a solution to your situation but just a consideration before some contractor talks you into something expensive that would make things worse.
The fan will at least keep you from a mildew problem hopefully. You Kanuks get your power cheap and fans don't use enough to say so anyways. If you are having that problem regularly you may have to get that sheet rock off the floor so it doesn't go to hell by absorbing moisture. If it was me I would remove the molding in that area and make sure it isn't touching the wet. If it was I would cut it back enough that it wasn't. It would also be a good idea to seal hell out of the ends of those studs with the best waterproofer you can find so they don't do the same. If you leave that molding gap open at least the fans airflow can get in there and keep things dry so you won't have any mold problems ( hopefully).
If you have to get in there to see the leaky area of course you will need to remove the drywall which will be a PITA to consider. If thats the road you choose they do make DRYLOCK which is a sort of concrete paint sealer for leaky block walls. You probably have seen the display in stores at some time or another. For cracks I would go with 3M 5200 marine sealer. Its expensive at $15 a tube but they use it to seal holes and fittings in fiberglass boats under water. Windshield urethane from NAPA is the same but it dries in the tube after its opened in a couple days so use it all. Both make construction silicons look like junk and they are adhesives as well as sealants. Look at your cars windshield thats what holds it in and just try to get one out without breaking it............................... The fan while a band aid solution really does work. If you get into the contractor thing just make sure they don't talk you into a big wallet solution that doesn't work any better than the humble fan. Some of the Customs houses I work at are built on swamps in the 30's with leaky walls and permanently full sumps all year long. I have seen lots of fans running in those over the years. They aren't wet all that often
