Can Heavy Rain Cause Sewer Backup?

Can Heavy Rain Cause Sewer Backup?

Heavy rain is a fact of life in most areas around the world. While it can be refreshing and calming to see, it also brings with it a number of issues that have to be considered. Oftentimes many people associate heavy rain with flooding and sewer backup. Although flooding and sewer backup are more common occurrences after heavy rain, this does not mean that rain is the main cause of these occurrences. Instead, the influx of water observed during heavy rain most often exposes flaws or pre-existing issues with the sewer and drainage systems. Making this important distinction when dealing with these issues is vital to knowing how to properly prepare your sewer systems for heavy rain.

Types of City Sewer Backups After Heavy Rain

While heavy rain is not necessarily the root cause of city sewer backups, it is, however, important to understand the several types of issues associated with city sewer backups and precipitation. Heavy rain can be an issue for city sewer lines as it creates an increase in the amount of water flowing through your pipes, potentially causing more damage to your property. In order to be prepared for whatever situation may arise, it is important to know what can contribute to a city sewer backup and the best solutions to mitigate damage.


One common contributor to city sewer backups after heavy rain is flooding. In this instance flooding will be referred to differently than an excess of rain. This means that flooding can come from a breach in local levees or even surges from powerful storms such as hurricanes.

Additionally, in many parts of the country a less commonly known issue is extremely prevalent. This issue is known as groundwater flooding. This occurs when the local water table underground becomes so heavily saturated that it actually rises above ground level. Groundwater flooding can become exaggerated and worsened when sewage and drainage systems have breaches in them. When this happens, sewage can become mixed with flood waters which can slow the waters from returning to normal levels and result in a city sewer backup.

Tree Roots in Sewer Line

Breaches in city sewer lines can cause severe issues during heavy rain events. One of the most common breaches in sewer lines is caused by tree roots. For many parts of the country, communities pride themselves on having beautiful landscaping, utilizing trees including oaks and banyans which have some of the most vast root systems in nature. The root systems of these trees often grow around sewer systems which can cause cracks in the lines. They have even been known to grow directly into the sewer system. Not only does this cause the issues associated with breaches in sewer lines but, this also puts added stress on the line during storms which can lead to catastrophic sewage failures and a city sewer backups.

Storm Debris

Another contributor to city sewer backups is storm debris. Storm debris can come in many forms such as uprooted plants and trees, loose garbage, broken street signs, and even pieces of buildings and vehicles depending on the severity of the storm. Many people might argue that storm debris is hard to prepare for since most storm debris accumulates during storms themselves. Although this is true, it is important to have your sewer lines inspected after storms to clear storm debris after the fact to prevent worsened flooding in the future. If storm debris is left in sewer lines then even light rainfalls can lead to flooding and a city sewer backup.

Sewer Line Inspections Help Mitigate Sewer Overflow from Heavy Rain

With so many potential causes for blocking and damaging city sewer lines, it is important to take proactive measures to mitigate and prevent city sewer backup. Performing routine sewer line inspections can help identify potential line issues before they become a serious threat. City sewer backups and overflows cause a number of problems including bacteria contamination, property destruction, and even compromise infrastructure among many other problems. A relevant example of this type of issue was seen on the coast of Florida after hurricane Ian in September of 2022. In the first week alone after hurricane Ian, “357,300 gallons of raw sewage were discharged from city manholes in the south beaches area.” This type of catastrophic city sewer backup could have been prevented if sewer line inspections were conducted before the storm. While many sewer line backups are not caused by large storm events like hurricanes, they can come from everyday rainstorms. This makes it pertinent to have regular sewer line inspections to avoid extreme outcomes.

Infosense Does Sewer Inspections Which Can Help Prevent Flooding

Now that you know about the importance of sewer inspections, where should you go to have the highest quality inspections? Infosense provides high quality sewer inspections that can help prevent flooding and city sewer backups by using our unique Sewer Line Rapid Assessment Test (SL-RAT) technology in conjunction with our amazing Sewer Line Data Organizer (SL-DOG) program to produce accurate scans in comprehensive data sets. Heavy rain can happen at any time, don’t wait for a catastrophe to get your sewers inspected. Contact us today to learn more!

InfoSense, Inc.
2102 Cambridge Beltway Drive
Suite D-1
Charlotte, NC 28273