Need to capture stormwater water from flooded areas with a catch basin that outlets deeper in the ground? No problem. Give your catch basin the extra height it needs to collect water from your lawn, landscaping, under downspouts, patios, and walkways. This durable catch basin extension adds up to 6 in. of height to your stormwater catch basin, eliminating the hassle of regrading or awkward piping. The 6 in. Riser can be cut to size with a saw to accommodate your project needs. It’s designed to work with a 12 in. square catch basin and accommodates a 12 in. square catch basin drain grate, or drain cover, on top. The riser is made of high-impact polystyrene (HIPS) treated with UV inhibitors.