Help needed regarding water ingress

[JW5]

My Daughter has a BMW 2014 1 Series & there is water leaking on the driver's floor mat, she first noticed this happening since about Feb this year & has owned the car since July 17, only part of the mat is wet which is closest to the door.
Could anyone please direct me as to what could be causing this?
Many thanks in advance.

[Pazuzu]

I would check the door seal first.

[Geffg]

Might be same issue I had with rear door of mine which was the membrane between the door and the door panel. The bottom corner, the sealant had come away allowing water to run into the footwell.
Tell tale sign on it which I didn’t know at the time was always when raining etc there was always condensation / wet on the sill plate when I opened the door.
If not that could be blocked drain in engine bay or sunroof pipe?

[JW5]

Thank you both, these are useful ideas to get the ball rolling.