Storm Drain vs. Sewer – What Are the Differences?

When it comes to your property’s plumbing and drainage systems, understanding the difference between a storm drain and sewer can save you from confusion and potential issues.

While both are crucial for managing water, they serve distinct purposes and handle very different types of waste.

Here’s a close look at how storm drains and sewers work, their differences, and why they matter for your home or business.

What Is a Storm Drain?

Storm drains are designed to manage rainwater and runoff. They’re the grates you see on streets, parking lots, or near curbs, and their main purpose is to prevent flooding by directing rainwater into a network of pipes that lead to nearby bodies of water like rivers, lakes, or retention ponds. 

Unlike sewers, storm drains don’t treat water—whatever flows in goes directly out.

Key Points About Storm Drains

  • Handle rainwater and runoff only.
  • Direct water to natural waterways without treatment.
  • Often found on roads, parking lots, and near curbs.

What Is a Sewer?

Sewers, on the other hand, are all about wastewater. They’re part of a closed system that carries water from sinks, showers, toilets, and other plumbing fixtures to a wastewater treatment plant.

Unlike storm drains, sewers are designed to treat and process water before it’s released into the environment.

Key Points About Sewers

  • Handle wastewater from homes and businesses.
  • Direct water to treatment plants for processing.
  • Designed to remove contaminants before releasing water.

Storm Drain Vs. Sewer – Key Differences

Now that you know what each system does, let’s break down the significant differences between a storm drain vs. sewer:

  • Purpose: Storm drains are for rainwater and runoff, while sewers handle wastewater from indoor plumbing.
  • Treatment: Water from storm drains goes untreated into natural waterways, while sewer water is processed at treatment plants to remove contaminants.
  • Connection: Storm drains are part of a public drainage system, while sewers connect directly to the plumbing in homes and businesses.

Understanding these differences is essential for managing your property’s plumbing and ensuring you comply with local regulations.

Why It’s Important to Know the Difference

Understanding the difference between a storm drain vs. sewer isn’t just about terminology—it’s about protecting your property and the environment. 

For example, pouring chemicals or waste into a storm drain can harm local waterways since the water isn’t treated. Similarly, during construction, mismanaging connections between storm drains and sewers can lead to fines, flooding, or system failures.

Knowing which system handles what is vital for property owners and builders when planning drainage solutions or performing maintenance. This ensures that each system operates as intended and keeps your property safe and functional.

Let Litteken Plumbing Help You Manage Your Systems

Understanding how storm drains and sewers work is key to a functional and efficient plumbing system, whether building from the ground up or maintaining an existing property.

At Litteken Plumbing, we specialize in new construction plumbing for both commercial and residential projects. From stormwater management to sewer connections, we’ve got you covered.

Need help or advice? Contact us today to learn how we can assist with your plumbing needs.