The water at High Creek Camp is pretty reliable, and you shouldn’t have to worry about it.
Take a look at this map: https://caltopo.com/m/5EJT
The creek forks right about where the trail to the peak crosses the creek. Water is usually in the right branch of the creek. The right branch is smaller, but it’s the one that has water. Sometimes you have to go a little ways up the right branch to find water.
The camping area is on the west bank of the left branch of the creek.
If ever there were not water up the right branch — which I have never seen completely dry, you can always walk down the creek toward High Meadow Falls. There is always water just upstream of the falls.