Parking Lot and Drainage Rehabilitation for a Commercial Property Owner in Nashville

The Challenge

Drainage and settlement issues causing pooling water.

A commercial property in the Nashville area was dealing with long-standing drainage and settlement issues. A sloped embankment directed stormwater runoff directly toward the parking lot, causing water to pool along a makeshift pedestrian walkway during rain events. The existing French drain was poorly designed and overwhelmed, leading to pooling as deep as six inches across a 30-foot-wide area. The runoff contributed to significant slab settlement—up to 3.5 inches—and cracking throughout the asphalt as water continually eroded the supporting soils beneath.

Key Facts

The Solution

85 total polyurethane injections.

To stabilize the affected area and redirect stormwater, Groundworks performed both surface and shallow soil injections using geotechnical polyurethane. The injection plan included approximately 65 surface-level injection points and nearly 20 soil injections reaching a depth of up to two feet, focused primarily along the curb line. Injections started at depth to provide a stable base, then proceeded to surface injections across four rows. Additionally, Groundworks modified the existing grade by removing and repaving select asphalt sections near the curb to improve slope. These new drop-in LID (Low Impact Development) cutouts enhanced water flow into the French drain. All injection work was performed through the asphalt, and the project was completed over two days.

The Impact

Proper drainage grading and mitigated surface water pooling.

The slab was successfully lifted up to 3 inches to both correct the 2–3.5 inches of settlement and reestablish proper drainage grades. Water testing after injection confirmed that runoff was now being effectively channeled to the French drain system between lift points. The solution eliminated surface pooling and stabilized the subgrade without excavation or significant disruption to tenant operations. Approximately 100 linear feet of parking lot and pedestrian access were rehabilitated.