Surprise, Surprise!

I've been planning to insulate and drywall in the closet under the stairs to my finished basement (below ground level).

Yesterday I found a nice puddle of water so the hunt was on, the wall/floor I had sealed but I guess the only spot I had missed was where it came in. I noticed water coming in around the floor beam and I cut it out to take a further look. Also took out a part of the particleboard. Between the floor and the wall there is a 1/4 inch gap! with just dirt, I put a screwdriver in and its pretty wet so this is were water came in. We did have a good rainstorm and my subpump has been going now than then too. The house is 150 years old, but the additon is from the 80's, I bougth the house this year. Finding new fun treasures every day...blah.

What is the best way to seal it?

Fill in concrete?

Can I fill in concrete while its still wet?

Like to get new drywall up soon :)

Thanks