If everything is sloped away from the foundation as it should be, and you have landscaping and drainage done there could be a high water table or underground spring or water recharge area.

What type of soil you have in the area?

If you have a high water table and the basement was dug to deep, each time it rains the water will rise. In addition being the highest house on the block really doesn't mean anything, I dealt with some foundations being on the top of the hill but the water table was 3' down so the basement floor was had to be above that.

If you had a bunch of people there and no one knows where the water is coming from, maybe be a good idea is to get an engineer and do a soil test and see if you have a high water table. You can also call the engineering department at the township and ask them if there is a seasonal high water table in the area.

Good luck

Thank you so much! That is what I was afraid of :(

I had a similar basement flooding issue and it turned out that the underground drain lines that the downspouts emptied into were clogged with roots and silt. After going with surface draining of the downspouts, all was dry.

YMMV