Cat litter. As pocketdoor sayes, if the water pressure goes there is nothing to flush the toilet. So after that last flush, put 2 garbage bags in your toilet and a few scoops of cat litter. Every time you go, cover it with more litter, but do not allow the bags to get so heavy that you cannot lift them out of the toilet. Store them somewhere until you get garbage service back. (Good luck!)
That cat litter advice is great! Thanks!