Where is the water entering?
Walls
Look for wet cracks, damp block or concrete, streaking and staining.
Wall-floor joint
Water along the perimeter can point toward groundwater or drainage issues.
Floor
Water appearing through floor cracks or low areas may be related to pressure below the slab.
One isolated spot
A localized crack, penetration or plumbing issue may need targeted investigation.
Does it happen after rain?
Rain timing is useful. Check gutters, downspouts, low soil near the house, sump activity, and the exact point where the basement first becomes wet.
When recurring water needs a larger solution
If basic exterior water management is in good shape and seepage keeps returning, basement drainage or waterproofing options may need to be evaluated.