Unfortunately, watering can be both time consuming and logistically difficult so it's important to find a watering method that works for you and your farm.
Unless you have a coated footing, dust control will most likely be an issue for your arena, especially if it's an indoor. Watering is the preferred method for treating dust because it also helps to bind and stabilize the footing, is usually readily available, and tends to be either free or at the very least relatively affordable.
All footing moves around and all arenas should be harrowed regularly and properly to address this. Improper equipment and techniques can do costly damage to your arena and have the potential to injure your horse.
Arena Maintenance = Grooming & Dust Control
Regardless of the type of footing you have, you MUST have a maintenance plan.
PROPER MAINTENANCE is the KEY to good footing.