Every parking lot gets wet. A healthy one is dry again within an hour or two after the rain stops. If water is still sitting in the same spots the next morning, the lot is telling you something about its shape, its base or its drains. Here is how those puddles form and what you can do about them.
Why asphalt lots hold water
The lot was never pitched correctly
A parking lot needs a gentle, consistent slope so water runs toward inlets, swales or the edge of the property. If the grade was set too flat during construction, or the crew paved over low areas without correcting them, water has nowhere to go. These “birdbaths” usually show up within the first year.
The ground underneath has settled
Over time, soft soil or a thin base can compress under traffic. The asphalt follows it down and a shallow bowl forms. This is common where lots were built over fill, near old utility trenches, and in the low, wet areas found in parts of Monmouth and Middlesex counties.
Heavy loads have pushed the surface
Trucks that stop and turn in the same places, especially on hot summer days, can rut or depress the asphalt. Loading zones, dumpster areas and drive-thru lanes are typical problem spots.
Drains are blocked or sitting too high
Catch basins full of leaves, sand and litter cannot do their job. In some lots the inlet frame sits slightly higher than the surrounding pavement, so water pools around it instead of going in.
Earlier repairs were not set flush
A repaired section that sits higher or lower than the pavement around it can dam water or create a pocket for it.
Why standing water matters
Puddles are more than an annoyance for customers stepping out of their cars. Water that sits on asphalt slowly works its way into small cracks and down to the base. In a New Jersey winter, that water freezes and expands, then thaws, again and again. That cycle loosens the surface and is one of the main reasons holes appear in the same places year after year. Standing water also freezes into slick spots, which is a slip-and-fall concern for any business or HOA.
What to do about puddles
Start with the easy fixes
Clean out catch basins and inlet grates, especially after fall leaf drop and after winter sanding. Make sure roof leaders and downspouts from nearby buildings are not dumping water onto the lot where it cannot drain away. Keep landscaping from building up along curbs and blocking runoff.
Mark the problem areas
After a good rain, walk the lot and note where water collects and how long it stays. Photos help. That information is useful for anyone pricing a repair, because it shows whether the issue is a few isolated spots or a lot-wide grading problem.
Fix the drainage around isolated low spots
A single low spot near an inlet or along a curb often comes from a clogged or high catch basin, a downspout or an edge with no place for water to go. Clearing the basin, redirecting the downspout and correcting the edge can get water moving again. Where the low spot is part of a worn lot, it is corrected during milling and repaving, as our asphalt milling page explains.
Correct the grade when the problem is widespread
If puddles appear across large parts of the lot, spot fixes will not solve it. Milling the surface and repaving with corrected slopes, or rebuilding the base in the worst sections, gets water moving again. It is more work up front, but it stops the cycle of repairing the same areas every spring.
Plan drainage into any repaving
When we repave a lot, we look at where water is coming from and where it needs to go before any asphalt is laid. That is part of how we approach every asphalt parking lot paving project. To learn more about the long-term effects of water, read why proper drainage is important for your parking lot, and for other issues worth watching, see potential problems that can damage your parking lot.
Need this done right?
Dan The Paver handles parking lot paving across Monmouth, Ocean (Toms River and north) and southern Middlesex counties. Free on-site estimates.