ALOHA Festival is being held right next to Lydgate County Campground.
Campsites at Lydgate are available through Kauai County for $25/night for non-locals ($5/night for Hawaii residents) and can accommodate up to 10 campers Thurs-Mon (the park closes Tues-Thurs).
Since this is a county park, you must reserve your campsite directly through the county by filling out the form you can download HERE.
Mail-in forms must be submitted no later than August 20 with copies of your ID and either a money order or cashiers check, and will be granted upon availability. Otherwise camping permits may also be obtained in-person at a camping permit location on-island. More details about camping permits and other campgrounds around the island can be found at the county's website.