What Is a Catch Basin Grate?

A catch basin grate covers a chamber used for stormwater collection to keep debris out. Grates trap large objects like leaves, paper, and plastic bags to keep them out of the drainage system. The underlying catch basin acts as a holding chamber for smaller debris to trap it before it enters the pipe which carries the water to a holding facility, sewage treatment plant, or outlet. Regular maintenance is necessary to keep stormwater collection systems operating safely and effectively.

Many grates are flat, although bulged designs are available for areas where large amounts of debris may be present. The advantage of a convex design is that it traps more material and is less likely to clog in heavy weather. It can present a tripping hazard, however, so the catch basin grate cannot be located in an area where people are likely to walk. Gardeners may use this style for drainage systems in beds and other areas where there is not a lot of foot traffic.

Plastic and metal can be used in the construction of a catch basin grate. If the grate is not likely to be visible, it may have a basic plastic grid design, as it needs to function effectively and doesn’t need to be attractive. Decorative grates may be used in public areas and locations where people are likely to see the grate. These can include patterned grids like circles or nature designs, as well as metals like brass that may have a more interesting visual appearance than plastics.

Maintenance for a catch basin grate includes periodically removing debris to prevent clogs. It’s important to keep water flowing freely to prevent problems caused by backups. The grate can also be swung or lifted out of the way to clean the sump underneath. Sumps can clog over time, creating backflow even if the grate is clear. Regularly scheduled checks can ensure that an entire drainage system is routinely cleaned and maintained so it will work well in storms.

In regions where stormwater drains into the ocean or a public waterway, the catch basin grate may include a sign warning people about this. Dumping chemicals, untreated waste, or other hazards into the drainage system could pose a public health problem because the water isn’t treated before release. People may be asked to be careful about what enters the system, and to report cases of suspected dumping such as releases of antifreeze or motor oil directly into storm drains.