Storm drains are one of those things you don’t often think about—until there’s a problem. On commercial properties, they’re quietly working in the background, diverting rainwater, snowmelt, and runoff away from buildings and high-traffic areas. But when storm drains become blocked, the consequences can be far more than a minor inconvenience. They can result in costly damage, safety hazards, and even legal issues. That’s why regular maintenance, especially catch basin cleaning, is essential for anyone managing a commercial property.
When storm drains are functioning properly, they collect excess surface water and route it safely through underground pipes to prevent pooling or flooding. The system includes grates and inlets at surface level that lead to basins or piping networks. These drains are designed to handle heavy volumes of water from expansive hardscaped surfaces like parking lots, rooftops, and walkways—all of which are common on commercial sites. But as with any infrastructure, storm drains require upkeep. When debris like leaves, garbage, or sediment clogs the system, serious issues can develop fast.
What Are Storm Drains and How Do They Work?
Storm drains are part of a property’s surface water management system. Their main purpose is to move rainwater and runoff away from paved and developed areas and prevent it from pooling in places where it could do damage. On most commercial sites, you’ll find them positioned in low-lying areas like driveways, near entrances, or in the middle of parking lots. Water flows into these grates and enters a chamber—often a catch basin—that temporarily holds it before allowing it to continue through underground pipes into either the municipal storm system or a nearby water retention area.
These drains aren’t built to handle just water. They’re designed to separate solids from liquids. The sump or basin inside collects debris and sediment so it doesn’t travel further into the drainage system. Over time, however, this debris builds up. Without scheduled maintenance, blockages form and water can no longer move efficiently. What’s out of sight quickly becomes a very real and very visible problem.
Common Causes of Storm Drain Blockages
Commercial properties are especially vulnerable to storm drain blockages because of the volume of traffic and surface area involved. Leaves, dirt, cigarette butts, food wrappers, and even shopping cart wheels can all find their way into storm drains. Seasonal changes also play a role. In the fall, leaves and pine needles pile up. In the winter, sand, salt, and slush build up. In spring, pollen, grass clippings, and loose soil add to the mess.
Some blockages stem from structural issues, not just surface debris. Tree roots can infiltrate underground piping, narrowing the passageway and catching debris. In older systems, pipe collapses or misaligned joints may also block water flow. When heavy rains hit a poorly maintained system, it simply can’t cope.
Immediate Risks of Blocked Storm Drains
The most immediate issue you’ll see from a blocked storm drain is flooding. Commercial parking lots, loading docks, walkways, and entrances can all become waterlogged during or after a storm. This isn’t just inconvenient—it’s dangerous. Standing water can lead to slip-and-fall incidents, posing a legal risk for property owners. It can also make it difficult for employees, customers, or delivery vehicles to access the building.
Water pooling in these areas also damages the surface materials. Asphalt and concrete begin to erode or crack under the constant stress of water exposure. Potholes develop, making areas unsafe to walk or drive through. Drainage that’s blocked in one area may also back up into others, causing cascading failures across the property.
Long-Term Structural Damage and Liability
If surface water consistently has nowhere to go, it starts to find its own path—and that path is often through your building’s foundation. Repeated water exposure can weaken walls, soak insulation, and create ideal conditions for mould growth. Water infiltration through cracks and joints can also reach mechanical or electrical rooms, leading to expensive repairs and serious safety concerns.
From a liability perspective, blocked storm drains are a major risk. Property owners are responsible for ensuring the safety of their premises. If flooding leads to property damage, personal injury, or business disruption, the costs go beyond repair—they can include lawsuits and penalties. Many municipalities also have regulations requiring stormwater systems to be properly maintained. Failing to comply can result in fines or mandated repairs at your expense.
Environmental and Reputational Impacts
Blocked storm drains don’t just affect your property—they can impact the broader environment. When a clogged system overflows, it can carry trash, oil, and chemicals into local waterways. This kind of runoff pollutes lakes, rivers, and stormwater ponds, affecting wildlife and water quality. Many regions now enforce strict guidelines around stormwater management to protect the environment.
Beyond environmental concerns, there’s your reputation to think about. Commercial properties need to project professionalism. When visitors or clients see water pooling, garbage floating around drains, or cracks in your pavement, it affects how they perceive your business. A neglected stormwater system reflects poorly on your brand, especially if your business relies on foot traffic or visual appeal.
Preventative Measures and Maintenance Best Practices
Fortunately, preventing storm drain issues is straightforward with the right plan in place. Regular catch basin cleaning is the most effective measure. Ideally, this should be done at least twice a year—once in the spring and again in the fall. Properties with more exposure to debris or higher traffic may need more frequent cleaning.
In addition to cleaning, regular inspections can help you identify potential problems before they become emergencies. A professional service can inspect for structural issues, check for signs of root intrusion, and confirm that the system is functioning as designed. Installing sediment traps, grates with finer screens, or even signage to prevent dumping near drains can also help.
Keep a maintenance log. Not only does this help you stay organized, but it also provides documentation that you’ve taken proper steps in case of a dispute or inspection. Preventative care costs far less than emergency repairs—and it helps keep your property safe, clean, and compliant.
Let Those Storm Drains Do Their Job (So You Don’t Have To)
Out of sight shouldn’t mean out of mind—especially when it comes to storm drains. What starts as a bit of debris can snowball into serious damage, safety hazards, and legal trouble if ignored. Commercial properties depend on well-functioning drainage systems to stay operational, safe, and presentable. Making storm drain care part of your property maintenance plan, with scheduled catch basin cleaning, is more than a good idea—it’s a necessity. Keep the water flowing where it should go, and you’ll protect your building, your budget, and your business’s reputation.
