Silt Saver Under Grate City Bag Reusable stormwater trash collection device.

The Silt Saver Under Grate City Bag is a reusable, under-grate trash collection device designed to fit unobtrusively inside catch basins beneath parking lot storm drain grates. It captures trash, floatables, and debris generated at festivals, street parties, and urban events, preventing those materials from entering stormwater pipes, sumps, and waterways. It is categorized as an inlet protection solution for municipal and commercial stormwater management.

The City Bag is constructed from a high-flow 9×9 scrim mesh fabric with a clear water flow rate exceeding 1,100 gallons per minute per square foot (gpm/ft²), allowing stormwater to pass through rapidly without impeding drainage. Integrated overflow ports provide an additional safeguard, ensuring water can escape the catch basin even when the bag is holding a significant volume of collected debris. This open-weave, anti-clogging design means the bag protects waterways without creating a surface flooding risk above the grate.

The City Bag installs directly inside the catch basin beneath the parking lot grate and does not require tools or specialized labor. Its one-piece, load-bearing design supports the weight of traffic above, while integrated handles allow crews to lower the bag into position and lift it out for emptying or replacement quickly and safely.

The Under Grate City Bag is available in eight standard sizes to fit a wide range of catch basin grate dimensions: 12″×48″, 21″×29″, 24″×24″, 24″×48″, 27″×27″, 28″×36″, 36″×36″, and 40″×55″. This size range is designed to accommodate the most common parking lot and municipal storm drain grate configurations without requiring custom fabrication. Selecting the correct size ensures a secure fit inside the catch basin and maximizes debris capture efficiency.

The Under Grate City Bag reduces the frequency and cost of basin and pipe system cleaning by intercepting trash and floatables at the inlet before they migrate downstream into sumps and stormwater infrastructure. Rather than allowing debris to accumulate inside pipes – where removal is costly and disruptive – the City Bag consolidates waste in a single, easily accessible location beneath the grate. This makes post-event cleanup faster, lowers long-term maintenance costs, and supports stormwater compliance goals by keeping pollutants out of waterways.

Yes, the Under Grate City Bag is designed for repeated use, making it a cost-effective and sustainable inlet protection solution for recurring events and ongoing municipal stormwater management. After emptying collected debris, the bag can be reinserted into the catch basin and returned to service. Its durable open-weave scrim mesh construction is built to withstand load-bearing conditions from traffic above while maintaining structural integrity through multiple use cycles.

No – the City Bag is specifically engineered with a load-supporting harness and one-piece structural design that allows it to bear the weight of traffic passing over the grate above. It sits entirely within the catch basin below the grate surface, so there is no visible obstruction or change to the roadway or pedestrian surface. This makes it suitable for active parking lots, streets, and event venues where vehicle and foot traffic cannot be interrupted.