I've never had any problems with water along the way. There really are not a lot of crossings, if you are utilizing Cottonwood Pass. Two of note as you enter forest from the open meadow, the Chicken Spring Lake outlet early in the year, lower Rock Creek and Whitney Creek at Upper Crabtree.
BTW, you pick up your WAG bag after you cross Whitney Creek and enter the Whitney Zone. Have fun finding the sitdown toilet in Upper Crabtree, after a few day of digging wholes this is a real treat.