Silt Saver Under Grate Sediment Bag Durable and reusable under grate sediment collection.

The Silt Saver Under Grate Sediment Bag is a woven polypropylene geotextile inlet protection device that installs directly inside a stormwater catch basin, beneath the grate, to capture sediment, trash, and floatable debris before it enters drainage pipes and downstream waterways. It is classified as a Best Management Practice (BMP) for stormwater inlet protection and is used on construction sites, roadways, and municipal drainage systems to meet sediment control compliance requirements.

The bag is constructed from 40-sieve woven polypropylene geotextile fabric, which allows water to pass through while retaining fine sediment and particulate matter – functioning as a permeable barrier between surface runoff and the subsurface pipe system. Integrated stormwater overflow ports are built into the bag to prevent ponding and localized flooding during high-intensity rain events.

Installation requires no special tools — the bag is placed inside the catch basin below the grate, with the load-supporting harness resting on the basin frame to bear the structural weight of traffic above. The easy-in, easy-out one-piece design and integrated handles allow workers to install, remove, clean, and replace the bag quickly with minimal labor.

The Silt Saver Under Grate Sediment Bag installs entirely beneath the grate inside the catch basin, meaning it does not interfere with traffic flow, pedestrian access, or surface drainage patterns above the inlet. This makes it particularly effective in active roadway, urban, and high-traffic construction environments where surface-mounted inlet protection devices are impractical or create obstruction hazards.

The Under Grate Sediment Bag is designed to be reusable – it is constructed from UV-resistant, durable woven polypropylene that withstands repeated cleaning and reinstallation cycles across the life of a project. High-visibility green edging allows inspectors and crew members to quickly confirm that sediment protection is in place during site inspections.

The Under Grate Sediment Bag is available in ten standard sizes to fit most catch basin grate configurations: 18″×36″, 21″×29″, 24″×24″, 24″×36″, 24″×48″, 27″×27″, 28″×36″, 36″×36″, 36″×48″, and 40″×55″. Selecting the correct size ensures a proper fit within the catch basin frame, maximizing sediment capture efficiency and structural load support.

Yes – by capturing sediment, debris, and floatables at the inlet before they enter the pipe system, the Under Grate Sediment Bag directly reduces the frequency and cost of catch basin cleanouts and downstream pipe flushing. It is an economical addition to any stormwater BMP program, providing measurable long-term savings on basin and pipe system maintenance.

The Under Grate Sediment Bag installs inside the catch basin below the grate and is best suited for drainage inlets in paved, high-traffic areas where surface obstruction is not acceptable, while a curb inlet filter mounts at the face of a curb opening to intercept sheet flow before it enters the inlet. Both products serve as stormwater inlet protection BMPs, but the appropriate choice depends on inlet configuration, site conditions, and traffic exposure.