Seat Mii water in front of vehicle

I noticed some water leaking out of the front wheel area, thought nothing of it. I left my car out in the rain & when I drove it around a corner heard a water sloshing noise coming from the front of the vehicle. I’ve looked under the bonnet & there doesn’t appear to be water collecting in the engine area, although there is a white substance collecting on the battery. There is obviously a water inlet but where is it & how do I stop water getting in, also can anyone tell me where the water is collecting. Also my wipers are behaving erratically, turning themselves on when I’ve switched them off.