Rock Filter Bags for Scour Control & Span Protection

Kyowa Filter Units are available in three sizes: 2 ton, 4 ton, and 8 ton. Each size is designed to accommodate different project scales and load requirements, with a safety factor of 6 across all sizes. The recommended aggregate fill size is 2 to 8 inches for the 2-ton and 4-ton bags.

Kyowa Filter Units are made from 100% recycled polyester (PET) using a unique Raschel knitting construction. This method provides exceptional flexibility, allowing the bags to conform to irregular ground contours while maintaining structural integrity in dynamic aquatic environments. The recycled content also supports sustainable construction practices.

Rock filter bags like Kyowa Filter Units are designed as permanent, long-term solutions. Their recycled polyester Raschel-knit construction is highly durable and resistant to the continuous hydrodynamic forces found in rivers, harbors, and marine environments, making them suitable for lasting infrastructure protection without the need for periodic replacement.

Yes, rock filter bags are specifically suited for bridge pile scour protection. Kyowa Filter Units can be placed around bridge pile foundations to dissipate water energy, prevent soil erosion, and maintain structural integrity. Their flexible shape allows them to conform tightly around piles and irregular surfaces in submerged environments.

Yes. The interstices within the Raschel-knit construction of Kyowa Filter Units create natural voids that support marine flora and fauna, including small fish and aquatic plants. This makes them an environmentally harmonious erosion control solution that integrates naturally into river and marine ecosystems while still providing full-scale scour protection.

Yes. Kyowa Filter Units feature a one-point lifting ring that enables fast, accurate installation even in limited-access or emergency repair situations. Their self-contained design eliminates the need for complex equipment, making them practical for rapid deployment at remote riverbank, harbor, or shoreline sites where time-sensitive repairs are required.