Water is leaking in onto the floor on the drivers side. what is it from?

Hi, there are several possibilities. There may be water leaking through the windshield seal and dripping down. You can try applying making tape around the edges of the windshield to see if it stops the leak. If a specific spot can be identified, some silicone RTV sealant can be squeezed in to reseal it. There may be a leak in the body seam at the bottom of the cowl (the well outside the car where the wipers sit under the bottom of the windshield. The cowl well is supposed to collect water draining from the windshield. The cowl is equipped with drain holes. There may be a seam where sheetmetal comes together in the cowl area that is not sealed good. You can try pouring water into the vents at the rear of the hood so the water goes into the cowl, and see if the water appears to enter the vehicle under the dash. Some disassembly is required to reseal the cowl sheetmetal seams.