I'm assuming your going to try to camp out on the blue trail for Fri night? If so, there's a few things you'll need to know...
1 - I'm no ranger, but the park has 2 approved backcountry campsites. Anywhere else, is considered against the regs and you can be fined. The known established campsites are: Yellow Trail - 1.6mi from N Trailhead & Orange Trail (have not measured distances). Just don't want to see you get fined.
2 - Here's a good trail guide (though a little dated) of Oak Mtn that may help you prepare:
http://www.alabamatrail.o.../hikingAL/OakMt/OakMt.htmCheck out the chimney's (red trail, couple miles in from N trailhead), the cabins near the lake (yellow by old lake), the dam/spillway (yellow trail near cabins), the ridge walking on the blue trail, maggies glen for a break.
Either way, you shouldn't have an issue with water.
Let us know how it goes!