Every inch of the carpet is soaked!
If done by some one who was thinking water might become a problem in a basement, they will have installed a carpet that can be used in a situation you have described. Have you a remnant go to some carpet place and ask and look at those carpets that are displayed to determine your situation. I say your OK.If its loose laid (that is not glued ) rent a wet or dry vacuum and suck up all the water you can. then place whatever you can under the carpet to allow it to drain more and place a fan so it can blow under it if possible if you can't get it up for what ever reason just keep the fan and wet or dry vac working.
Carpet is a very nasty thing to have in your house in the first place, it is dangerous when it is new and dirty when it is old. With that said, if you did not get the carpet out and aired or dried within 24 hours (drying needs to be one those large fans that go under your carpet. Was this leak a broken pipe or a flood from outside? If you have a leaky basement I would throw the carpet away and stain and seal the floor then put down rugs.
Depends really....If it is just water and it was not there for long then the answer is probably yes it can be saved But you will need to move quickly.Obviouly get rid of the standing water as soon as possible and then get some fans going and possibly some sort of heater to speed the drying .Its going to take days to dry out so be patient
eliminate the pad, dry carpet, put off carpet if mildewed or moldy, dry and manage basement with mildewcide. and do not call any of the restoration agencies that come out and would charge a huge volume merely because coverage is footing the invoice. previous journey with basement would element out you'd be better off doing away with the carpet. How about stained concrete
If it's that soaked, it will all have to come up anyway. If it was a decent carpeting job, it will have a foam underpadding and that will be soaked as well. Don't know where you're at, but around here we have a company called Servpro that handles such problems, even works with your insurance company to help get it paid for. There may be wicking occurring with the wall coverings as well, if there's drywall involved. I'd suggest looking in the yellow pages for a fire/flood restoration company that could help.