I lived in a 80 year old house with a leaky basement. One day we dug on the outside to see to our surprise that there was practically no mortar between blocks, some had tree roots between them. We called a friend of ours who parged the wall, then came back and put tar coating over it and finally, a sheet of plastic before backfilling. We also found out there was no footer underneath, just blocks on dirt!! There was also a terra cotta drain system on the outside up against the blocks that looked like it was clogged. We had this problem for 15 years, finally solved it last year and now moved to a new home with a leaky basement!!! Try renting a digger or getting someone to dig a small section out for you. It took my husband and I a couple of hours to dig it out, but it was worth it.Good luck! Let me know. P>S> My brother had a spring under his house. !!