Keeping below-grade living space dry requires creating dry air space next to the foundation well below the floor level. Remember that water can come up from below as well as down from above.

You will need to excavate and add drainage against the outside of the foundation that can carry the water away faster than it can rise from below or percolate from above.

Here’s a good example: https://youtu.be/hfUc4oIVsrY