Water in the enclosure
Water bowls need to be wide and shallow to allow for bathing, laying in or standing in and prevent drowning. The bearded dragon will more likely use the water to lay in than drink, but this also provides benefits from adding to hydration to enhanced environmental enrichment.
The bearded dragon may defecate in the water. If this is what encourages it to move its bowels then the water is still beneficial, however it is vital the water dish is cleaned thoroughly immediately afterwards. Do not leave fouled water in the enclosure especially if it is warm.
If the humidity is too high in the enclosure then it would not be suitable to add a water dish since it will simply increase the humidity. Fix the issue with the excessive humidity and then provide the water. Depriving the animal of continual access to clean water in preference to resolving the issue with the enclosure is not a solution.