If your toilet will not flush during a storm, you should call a plumber immediately. While it may be tempting to try to keep flushing it over and over or to let the storm blow over and try the toilet again later, waiting could cause more extensive problems with your septic system.
It is easy to assume a toilet just needs to be plunged if it is not working properly, but if the toilet will not flush after heavy rain and it seems like the water level in the bowl has risen or a sewage smell is present, these issues could indicate a bigger problem that needs to be addressed immediately.
The cause of the problem
This issue often arises in homes that are older, in lower elevations, or ones that have a septic tank that has not been recently pumped. It often occurs after a recent heavy rainfall during which the level of the water on and in the ground has risen to the level of the top of the septic tank and drain field. Essentially, the ground has become so waterlogged there is nowhere for the water in the septic system to drain. Some older homes have tanks that are not made of materials that keep the water from the ground out, or the ground above the tank and drain field has eroded over time, leaving them more susceptible to the effects of sitting groundwater. If a septic tank has not been recently pumped, the rainwater may overrun the capacity of the tank, preventing more waste from being flushed into it.
In some cases, the problem is that the home does not have a backwater valve that allows water from the septic tank to run back up into the house.
A plumber has the solution
In rare cases, the problem will fix itself after the ground has dried; however, it is still recommended that the septic system is checked by a plumber. The septic tank may need to be pumped to ensure it has plenty of space for waste during dry and wet days. A septic tank pumping should occur every 3-5 years. If this has not happened, one should be scheduled immediately. In some cases, especially in older homes, the septic tank is damaged or outdated and should be replaced to ensure this issue and other issues do not continue. While not as common of a problem, the drain field could be failing and may need to be reworked; however, the solution could be as easy as installing a backwater valve.
It is always the better choice to have your septic tank and system inspected by a professional. Failing septic systems are expensive to fix, which is why they should be routinely overlooked to prevent issues from getting larger. If you are having trouble flushing your toilet during a storm or you have other concerns, call in a plumber to assess the situation and ensure the proper function of your septic system.