If you want your parka to have some water repellency either take it to your dry cleaner and have it proofed or buy a can of 3M Scotch Guard and apply it yourself. Remember, like silicone spray for your shoes, you should keep the can about 12 > 15 inches away from the garment and mist the garment, moving around it quickly. Let that treatment dry in and give it another application. The more you put into it, the greater the efficacy.
This is a heritage brand and EG is determined to keep that aspect of it to its original character.