I know the original post is old, but water info is always helpful and since you posted just before Apple fire maybe you didn’t get to go yet!
There are locations along this trail that seem reliable for water all summer/fall (have not done the trail in winter).
A stream flows near Halfway camp (around mile 3.5). About two-thirds of the way up, I always stop to rest, have a snack, and refill at the robust stream that runs just past High Creek camp (maybe mile 6 or 7?). This is the final water source before the summit. Also perfect for a second rest/refill on the way back down.
This trail is great for not having to carry too much water, so long as you don’t mind stopping to filter. I never have more than about 1.5L with me at a given time.