Catch Basin

How Catch Basins Work

A catch basin sits at a low point in the pavement or landscape where water naturally collects. The grate on top lets water pass through while blocking large debris like leaves, trash, and branches. Below the grate, a concrete or precast box provides a sump, a recessed area below the outlet pipe, that traps sediment and smaller debris through gravity.

Water enters through the grate, fills the sump, and flows out through an outlet pipe connected to the storm drainage network. The sump prevents sediment from traveling downstream into pipes, where it would accumulate and reduce capacity over time.

Why They Matter for Property Owners

Catch basins are the entry points for your entire underground drainage system. When they fail, everything downstream suffers. A clogged catch basin causes surface flooding in parking lots, driveways, and landscaped areas. A cracked or settled catch basin allows soil to infiltrate the pipe network, creating voids that lead to sinkholes.

In coastal South Carolina and Georgia, catch basins face extra stress. Sandy soils migrate through cracks and joints. High water tables keep sumps saturated, accelerating concrete deterioration. Tropical storm debris overwhelms grates that haven’t been maintained.

Common Problems We See

The most frequent catch basin issues across the Lowcountry:

• Sediment-filled sumps that can’t trap anymore material, sending sand and debris directly into pipes
• Settled frames where the grate sits below the surrounding pavement, creating a tripping hazard and reducing intake capacity
• Cracked structures that allow soil infiltration and groundwater intrusion
• Root intrusion from nearby trees blocking the outlet pipe connection
• Corroded grates that break under vehicle traffic

When to Call a Professional

If you notice standing water near catch basins after rain, pavement sinking around drain grates, or water backing up onto surfaces that used to drain properly, it’s time for an inspection. AUE Land provides storm drainage services including catch basin cleaning, repair, and replacement across the Lowcountry.