Either water erodes the sub-base, or the stone base has settled and can no longer support the asphalt. Severe drain damage will require that asphalt be removed to even things out. The catch basin repair may require replacing the entire structure for the drain.
When deterioration is allowed to continue more water collects in holes and cracks. Then freezing and thawing continue over time, therefore creating more severe damage and repair costs. Leaving a catch basin neglected until a sinkhole develops could cause far more extensive damage to surrounding asphalt, and create liability issues.
If a catch basin or storm drain is older and may be beyond repair, we can completely dig out and rebuild the more extreme of cases. Preventative maintenance reduces costs and ensures long-lasting catch basins and drain structures while keeping the rest of your parking lot in good repair.