If this just happened all of a sudden and the noise is coming from both sides, you may have driven through something left on the road other than water... I recently took a 200 mile trip and somebody on the road left a trail of grease that ended up covering the whole front of my car and windshield.
Anyways, get some brake cleaner and clean up the rotors and pads to see if that eliminates the problem. Also, when spinning the rotors with the front wheels off, put the lug nuts back on and run them up snug against the rotors. Otherwise they won't be spinning true when your rotating them by hand.