Emergency Preparedness For Sinkholes
We often see or hear news reports of sinkholes that range in size and the damage that they cause. This article will discuss what sinkholes are, the different types, how they happen and the implications they have. It will also discuss the subject of sinkhole emergency preparedness.
According to the United States Geological Survey, the areas that suffer the most damage from sinkholes are Florida, Texas, Alabama, Missouri, Kentucky, Tennessee, and Pennsylvania. Although sinkholes can also happen anywhere in the world that has a soluble subsurface rock. So let’s take a look at sinkholes in more detail including some sinkhole emergency preparedness tips.
What Is A Sinkhole?
Sinkholes are sometimes called a shakehole, swallet, doline or a swallow hole. A sinkhole is basically a hole that opens up in the ground due to the erosion of the surface layer. Sinkholes can range in size from a few feet across to big enough to swallow up entire buildings. Most sinkholes occur naturally although some are caused by human activity like broken water or drain pipes, drilling, mining, and construction.
What Causes Sinkholes?
As mentioned earlier sinkholes normally occur in areas of land that have soluble bedrock, such as, limestone or gypsum which can be dissolved by water. Also known as karst terrain the bedrock becomes exposed and is gradually worn down over time. Cracks in the bedrock naturally occur and small voids underneath the surface are hollowed out by water erosion. The soil or sediment that is on the surface suddenly collapses and exposes the cavern underneath.
Are There Different Types Of Sinkholes?
There are two main types of Sinkhole:
- Sinkholes that happen slowly over time known as cover-subsidence sinkholes
- Sinkholes that suddenly appear known as cover-collapse sinkholes
As previously mentioned sinkholes can happen anywhere in the world that has a soluble subsurface rock. In the United States, this is mainly in Florida, Texas, Alabama, Missouri, Kentucky, Tennessee, and Pennsylvania but about 35 to 40% of the land in the U.S. has rock beneath the surface that is easily soluble with water.
Southern Italy has also experienced numerous sinkholes, as has China, Guatemala, and Mexico. It’s important to point out that sinkholes do not only form on land they can also form underwater. A good example of an underwater sinkhole would be the Great Blue Hole which is off the coast of Belize.
Sinkhole Emergency Preparedness Tips
The first step of sinkhole emergency preparedness is to improve your knowledge about the emergency warning signals and alert notifications used in your community. Following on from this you should check your property and its surrounding area for signs of a sinkhole forming for example:
In Your Property or Building Check For:
- Cracks in the exterior of the property, such as in the block or stucco
- Cracks in the interior of the property including areas along joints, windows, or doors
- Doors and windows that don’t close properly
- Sloping or uneven floors
- Muddy or cloudy well water
Outside Your Property check for:
- Previously buried items, such as fence posts, and trees becoming exposed as the ground sinks
- Gullies and areas of bare soil, that form as soil is carried towards the sinkhole
- A circular pattern of ground cracks around the sinking area
- Localized, gradual ground settlement
- Formation of small ponds, as rainfall accumulates in new areas
- Slumping or falling trees or fence posts
- Sudden ground openings or ground settlement
- Interrupted plumbing or electrical service due to damaged utility lines
- Dead or wilting vegetation caused by water being drawn away by the sinkhole
Basic Sinkhole Emergency Preparedness Actions
- Determine any risk in your locale and any hazards that go with them
- Familiarize yourself with the emergency plans of your family member’s employment building, school, day care center, or nursing home
- Develop an Emergency Communication Plan and evacuation plan and ask an out-of-state person to serve as a family contact
- Make the necessary preparations and arrangements for pets, seniors, and the disabled
- Make the necessary property preparations to reduce the damage from the hazard
- Instruct family members on how to shut off water, gas, and electricity to your property
- Do some first aid and CPR training
- Keep a backup generator for when of the power is out
- Create a shelter-in-place Emergency Supplies Kit
- Create a mobile Emergency Supplies Kit that you can grab and go if you need to evacuate
- Have some emergency backup cash for when a power outage shuts down banks and ATM’s
- Organize your important documents and store them in a portable lock box or safe-deposit box
- Perform home inventory, taking photo’s and video of your possessions
If a sinkhole suddenly starts to appear, you will need to quickly assess the situation and decide whether you’re going to evacuate or shelter in Place. If in doubt you should not take any chances and leave the immediate area in search of safer ground.
Here are some basic guidelines to follow if you have a sinkhole on or near your property:
- Don’t get too close, watch out for surface cracks and stay well back
- If the hole is very large and a risk to others, contact local police or emergency responders
- Keep children away
- Notify all local occupants
- Notify the local Water Management District
- Mark the hole for safety and to restrict access (Use posts with caution tape or rope)
- Place a piece of plywood over small holes
- Take photographs for documentation, but do not get too close to the edges
- Do not allow unauthorized or inexperienced persons to investigate the sinkhole
The main priorities after the occurrence of a Sinkhole will be to get disaster relief and undertake the tasks of clean-up and salvage. Refilling and repairing Sinkholes should only be carried out by qualified, reliable people or companies.
Do not refill a sinkhole with trash or debris because filling a sinkhole with waste materials is illegal and may cause groundwater contamination for which the property owner would be liable. If the amount of material needed to fill the hole it is too large for just soil then more materials such as concrete and large rock may be needed. Its also important to try to divert any excess water away from a hole before, during and after filling.
Sinkhole Emergency Preparedness Summary
Learning a much as you can about sinkholes, especially in the area you live in is important. Looking out for the signs of a cover-subsidence sinkhole is something you can do yourself. If you spot any or are not sure you can call in a professional to check. For cover-collapse sinkholes that can suddenly appear its important to prepare for what you would do including having an evacuation plan and emergency supplies.