What is water ballast in event rigging?

In event rigging, water ballast refers to containers—often heavy-duty bladders or tanks—filled with water to provide temporary, adjustable counterweight for structures such as lighting trusses, PA line array towers, and staging. Unlike fixed steel or concrete blocks, water ballast can be filled on-site, drained after use, and transported empty, making it ideal for touring and temporary installations where weight and logistics are critical.

Water ballast is commonly used to secure ground-supported PA towers, delay towers, and roof structures against wind uplift or tipping forces. SSOUNDS engineers often specify water ballast for large-scale outdoor events because it offers a high weight-to-volume ratio (1 liter of water = 1 kg) and can be precisely adjusted to meet safety margins. Proper calculation of ballast requirements—considering wind load, structure height, and safety factors—is essential to ensure stability.

Key advantages include low cost, easy availability, and environmental friendliness (water can be safely drained). However, water ballast must be protected from freezing in cold climates, and containers must be robust to prevent leaks. For permanent installations, concrete ballast is often preferred, but for touring and festivals, water ballast remains a flexible, efficient solution.