Our homes sewer lines and sewer system keeps things running smooth, carrying away both human waste and storm water. Our sewer system often does it's job so well that we hardly ever give it thought, that is until something goes wrong or upsets the system. Sewer systems like everything else deteriorate over time. Sewer systems and sewer lines also need maintenance to keep them running smoothly. If you are experiencing flooding due to your sewer lines it could be due to the issues that we will discuss below.
If your basement or property floods with backup water more often than not due to your sewer lines then you may might a backwater sanitary valve or if you already have one it may have failed. Backwater sanitary valves like anything mechanical are prone to failure with the passage of time and wear and tear over the years. What a backwater sanitary valve does is it only permits a one way flow of water in your sewer lines. When water rises on the downstream side of the valve, the valve then closes, to prevent backflow from occurring. These are often built into sewer laterals to offer protection against sewage backups. If you have an older home you might not have one of these installed in your sewer lines.
Several factors can also dictate if it performs correctly. It is vital that it be installed correctly. The proper placement of the backwater sanitary valves are also very critical in regards to weather they will perform under pressure in the expected manner. The type of backwater valve also matters. It also must be installed on your sanitary lateral so that it normally open so to as allow the correct flow of sewer gases through the homes ventilation stack. This also ensures that should the valve fail it will fail in the open position which is critical to avoid the build up of dangerous sewer gases. This valve must be maintained like any other plumbing fixtures, otherwise it will offer no protection in the event of a flood.
If you do have a backwater sanitary valve installed there are a few factors to be aware of. During heavy rainfall the valve may indeed close to protect you from flooding, during the time that the valve is closed you could flood yourself by using to much water. For example doing laundry or using the shower when the valve is shut could flood yourself as the water has no where to go during the time the valve is closed as it prevents the movement of water both in and out of the home. In effect it shuts down your sewer lateral. Also as stated placement of the valve is critical, for example if a weeping tile connects to your sewer lateral upstream of the backwater sanitary valve you could experience flooding as the water being drained by the weeping tile wont have anywhere to drain during the time that the valve is closed.
While having a backwater sanitary valve presents it's own unique set of problems as listed above, it offers excellent protection against flooding due to sewer backflow. Proper awareness and maintenance is all that is needed to mitigate the challenges posed by having this system in place. In order to have a backwater sanitary valve installed the work must be performed by a licensed plumber with a valid plumbing permit.
If you have a storm sewer line or lateral on your property, it can be a great outlet for storm and/or ground water to be drained. While it can come in handy your storm sewer lateral can present flooding risks when the storm sewer system is overflowing. If you make little use of your storm sewer line due to having other methods of drainage on your property, you should consider having the line severed near your property line. Severing your storm lateral however will require a permit in every case and the work must be performed by a licensed professional.
Nothing except routine regular inspection and maintenance will protect you against a flood due to a deteriorated sewer lateral. Your local licensed plumbing company should be consulted at least every 5 years to inspect your sewer lines.