The NDS 1216 6-inch catch basin riser raises a 12-inch square catch basin to improve surface drainage in lawns, landscaping and around structures. It provides a reliable, weather-resistant extension that simplifies installation and helps prevent surface flooding. Adds up to 6 in. of height to 12 in. catch basins; top measures 12-3/8" x 12-3/8" and overall height is 7-1/8". Constructed from high-impact polystyrene (HIPS) treated with UV inhibitors for long-term outdoor durability. Designed to fit the NDS 12 in. square catch basin series and to accept 12 in. square grates or covers for a clean, finished look. Can be cut to size on-site with a saw; when trimming a 12 in. riser, shave strengthening ribs so the riser will fit properly. Stackable for additional height—NDS recommends no more than five risers; backfill and compact soil between risers to prevent shifting. Use the 1216 riser when a standard basin sits below grade and you need up to 6 in. of added height without regrading. Its durable HIPS construction and compatibility with NDS 12 in. drainage components make it a practical choice for residential and commercial drainage projects.
