Annapolis, Md. — Maryland homeowners in parts of the state face a moderate risk of sinkholes, and experts say early warning signs often appear quietly before noticeable ground failures occur.
According to the U.S. Geological Survey, sections of Maryland sit atop limestone and other soluble rock formations, particularly in western and central regions of the state. This type of terrain, known as karst geology, can slowly erode as water moves underground, creating voids that weaken support beneath the surface. Heavy rainfall, prolonged wet periods, and shifts in groundwater levels can influence how quickly these changes develop.
Geologists emphasize that sinkholes rarely form suddenly. Instead, they typically develop over extended periods, with subtle surface changes acting as early indicators of underground erosion. Transitional seasons, such as late winter and early spring, are often when these warning signs become more visible as soil conditions shift and water infiltration increases.
Homeowners may notice shallow depressions forming in yards, soil that feels soft or spongy underfoot, or new areas of standing water that linger after rainfall. Cracks appearing in sidewalks, driveways, patios, or foundation walls can also reflect gradual ground movement rather than routine settling.
Other warning signs are frequently overlooked. Leaning fences, separating steps, tilting trees, or small gaps forming between soil and concrete surfaces may signal changes beneath the ground rather than normal wear.
Moderate sinkhole risk areas in Maryland include parts of the Appalachian Plateau and the Ridge and Valley region in the western portion of the state. Experts note that risk can vary significantly by neighborhood depending on local geology, drainage patterns, and soil composition.
The USGS cautions that once visible surface changes appear, erosion beneath the ground may already be underway. Homeowners are advised not to fill depressions or cover affected areas, as doing so can hide developing hazards.
Experts stress that awareness — not alarm — remains key. Monitoring subtle changes and seeking evaluation from local officials or qualified professionals can help reduce damage and improve safety as ground conditions evolve.
