While asphalt cracks and even potholes are relatively slow to progress and easy to repair, a sinkhole is entirely different. It can quickly swallow a great deal of land, taking cars, homes, and even people with it. If you find a sinkhole, it is imperative that you act quickly. Here is what you should do.
What Is a Sinkhole?
Sinkholes occur in what is known as karst terrain, where the bedrock under the ground’s surface are soluble, meaning that they can be dissolved by water. Limestone and gypsum are among the most common types of karst terrain.
As rainwater passes through the soil into the bedrock, it erodes the rock over time. This can lead to underground caverns and voids that can then fill up with water. A sinkhole forms when the bedrock can no longer support the ground’s surface, and the land collapses.
What Causes Sinkholes?
Sinkholes are the result of naturally occurring processes. However, human activity can make them far more likely to happen in specific places. For example, rainwater diversion can cut channels in the soil, forcing far more runoff into a small patch of bedrock than it would otherwise receive.
Types of Sinkholes
There are two basic types of sinkholes. A cover-subsidence sinkhole forms from the top down. The ground surface gradually washes away, exposing the bedrock and creating ponds, especially during heavy rains.
A cover-collapse sinkhole is far more dramatic, as there may be few or no warning signs. In this type of sinkhole, the bedrock has been eroding beneath the ground for a long time, unnoticed. When the bedrock can no longer support the land above it, the land suddenly collapses.
Fortunately, a sinkhole is localized. Though some can be several feet in diameter, and even swallow entire buildings, sinkholes do not spread beyond the area where the bedrock is eroded. The biggest risk comes from being on top of the area where a cover-collapse sinkhole forms. You may have just minutes to get away before toppling into a large hole.
What to Do if You Spot a Sinkhole
Signs of an impending sinkhole include leaning trees, signs, or fence posts, newly formed areas of ponding water, and small cracks in a building’s foundation. If you notice any of these signs, keep a close eye on the area in case of further development.
If you are inside a building or vehicle and feel the ground begin to give way, get out immediately. Make your way on foot several feet away, and then alert emergency personnel. Try to work with others to block off the area where the sinkhole is forming, but do not put yourself at risk.
If a small sinkhole of no more than 3 feet in diameter opens up on your property but away from any structures, it may be able to be filled. Contact your trusted asphalt contractor for assistance.
A sinkhole on your property is generally considered your responsibility. However, your homeowner’s insurance may cover any damage, depending on your policy. Have a property inspector and an insurance inspector take a look as soon as possible.
Based in Abbotsford, Topwest Asphalt also serves Langley, Chilliwack, Mission, and Maple Ridge. Are you ready to start your next asphalt project with a team you can count on to do the job right, on time, and on budget? We invite you to call Topwest Asphalt today at 1-800-ASPHALT to discuss your project and schedule an estimate. We look forward to working with you!