On every large property including condominiums, shopping plazas, or even football stadiums, storm drains help elevate flooding from a rainstorm. It’s only until we see the warning signs that fixing storm drains becomes a priority. Symptoms can range from seemingly harmless water slowly trickling into drain gutters to massive sinkholes that cause serious damage to roads and properties. Standing water after a 5-inch shower and even sinking pavement are indicators that the storm drains may not be working properly.
2 Reasons Why Storm Drains Fail
There are two significant factors that result in the failure of storm drains: clogged up catch basins and the material of the storm drain pipe. Catch basins often fill up with leaves, sticks, dirt, and other miscellaneous objects that block or even fill up the drain pipe. Chances are you’ve seen a catch basin in a parking lot or on the side of the street. The wide grates that cover the opening of the catch basin allow easy access for sticks, leaves, dirt and more.
Storm drains are typically engineered to carry a certain amount of water. Blocked storm drains can result in the pipe carrying more than 1⁄3 the volume it was originally designed. Therefore, producing standing water unable to pass through. Many storm drain basins are not cleaned for 30 to 40 year until there is an issue however, this can be easily fixed by having a routine cleaning of the catch basins and camera inspection of the drain pipe.
There are two kinds of pipe material that are commonly used as storm drain pipes: concrete and corrugated steel (a pipe that has metal grooves inside). Corrugated steel pipes have the tendency to corrode over time due to Microbiological Influenced Corrosion (MIC). Chemicals inside a pipe system are actively eating away at the metal in the pipe much like a parasite. Unfortunately, it’s only a matter of time until these nasty parasite like chemicals will erode away the pipe causing pinhole leaks and cracks.
Concrete pipes do not corrode like corrugated steel pipes however, they can produce just as many cracks and pinhole leaks. Concrete is heavy and because of the size of the pipe which ranges from 8 to 10 feet, multiple concrete pipes are joined together. These connecting joints sealed with a rubber gasket or concrete have the tendency to leak. For example, to seal a crack on a driveway many homeowners choose to concrete over the crack however, 5 years later it will crack again. The same is true with sealing pipe joints with concrete.
Since these 8-foot sections of pipe are extremely heavy, knockouts (holes) on either end of the pipe were made so that construction workers could thread a chain through each end to place the pipe where it needed to go. After the chain was removed from the pipe the holes were then covered with concrete or even bricks that were also covered with concrete. The odds of these knockouts leaking are highly likely over time.
Storm drain problems can happen anywhere in the Unites States and around the world. Slow water drainage, standing water/flooding, dips in the road, or sinkholes are all indicators that the pipes below are not functioning properly. A solution? By cleaning and inspecting storm drain pipes flooding and property damage can be minimized.