BMP's Catch Basin Donuts are designed to have the rainwater pond and filter into the catch basin near construction sites. Primary benefits of the catch basin include easy installation and even easier maintenance for your erosion control needs. Once the donut is installed, all that is required for maintenance is the use of a broom or shovel to remove the collected sediment around the catch basin. The filter fabric wraps around the grate and is fastened with the belting and buckles attached. The protected grate is then reinserted into the frame support.