What Is a Storm Drainage System? Components, Function & Why It Matters in DFW

A storm drainage system is designed with a network of inlets, pipes, channels, and detention areas that can hold the runoff from rainwater and keep everything moving in the direction of a safe discharge location. There is a difference between storm drainage and sanitary sewer systems because storm drainage only handles rainwater (not sewage or wastewater).

In DFW, heavy storms in the area can cause serious complications without the right storm drainage systems in place. If the water isn’t properly managed, it can result in flash flooding and foundation damage (or failure).

Failing to install a proper storm drainage system might result in expensive repair costs in the future, as well as regulatory liabilities. During the pre-construction planning phases, it’s critical that you are working with a trusted heavy civil contractor to ensure that your system meets all regulatory requirements. Moss Utilities is here to help.

What Is a Storm Drainage System?

A storm drainage system is designed to collect surface runoff water during a storm, then move the water to the desired location, such as a water channel or the municipal storm system. Properties typically need two water removal management systems: storm drainage for untreated rainwater and sanitary sewer systems for wastewater that needs to go to treatment facilities.

While public systems are in place to provide the right-of-way, property owners are responsible for the private systems that are installed on the other side of the curb. These private on-site storm drainage systems are installed on many different properties, including parking lots, larger campuses, multi-family properties, and commercial buildings.

How Does a Storm Drainage System Work? Step-by-Step

Even though the storm drainage system isn’t noticeable, there is a lot happening on the surface level and underground.

When it’s raining, the rainfall flows across the surfaces, which is when you can see the water running toward low points.
Surface collection channels are designed in storm drainage systems to catch the water, such as gutters, swales, and graded pavement, so that the runoff moves to the desired inlets.
These inlets capture the flow and move the water into underground conveyance pipes.
The underground pipes keep the water moving (by gravity) to a direct outfall location or a detention facility.
The detention ponds and underground water storage areas are sufficient to hold the peak flow volume during the largest storms. Then, the water is released at a controlled rate.
The water is finally discharged at the desired outfall, such as a creek or concrete channel, or into a municipal system.

Core Storm Drainage System Components

While every storm drainage system is unique and needs customized designs, there are some core components that are built into many of these systems, which might include:

Curb/Grate Inlets & Area Drains: These are the entry points where the surface water moves into the underground system.
Catch Basins & Junction Boxes: Underground structures are designed to connect the pipe runs and also allow the sediment to settle to avoid blockages in the system.
Storm Drain Pipes: These pipes must be large enough to hold the highest volumes of water. They are made with reinforced concrete, HDPE, PVC, and metal, based on the anticipated runoff load and the soil conditions on the site.
Detention Ponds & Underground Vaults: When peak flow occurs, the water can be held in these locations to prevent flooding downstream. Then, the water is released slowly.
Water Quality Equipment: Most DFW commercial projects need bioswales and hydrodynamic separators.
Headwalls & Energy Dissipators: These storm drainage system components help to reduce the risk of erosion at the discharge points.

Different Types of Storm Drainage Systems Used in DFW

Because of the heavy storms that move through Dallas-Fort Worth, there are different types of storm drainage systems that might be used (based on the unique requirements for each property). The most common types of systems include:

Closed Piped Systems: These systems are commonly used in commercial and urban developments. They are fully underground and keep the water from flowing on the surface between the buildings.
Open Channel Systems: Large ditches can be used to collect the water. These ditches are lined with concrete in high-density areas. Or, earthen ditches are sometimes sufficient for lower-density and public works applications.
Hybrid Low-Impact Development Systems: This type of storm drainage system combines traditional piping with other elements to support the environment, such as bioswales, permeable pavement, and green infrastructure.
Underground Detention Systems: Under the ground, chambers and oversized pipes are installed to store the water. These detention systems are usually placed under parking lots and developed sites

FAQ

What is the difference between a storm drain and a sewer?

A storm drain system is designed to capture and move untreated rainwater into a nearby channel or creek. On the other hand, a sewer system collects wastewater from homes and businesses to move the waste to a treatment facility.

Is storm drainage on my property my responsibility?

Yes, any drainage that needs to happen behind the curb is the responsibility of the property owner. You need to install, maintain, and prepare the storm drainage system located on your site.

What is the best pipe material for storm drainage in North Texas?

The most commonly used pipe material here in DFW is RCP. But private sites with lighter loads sometimes use HDPE.

Do I need a permit to install or modify storm drainage in DFW?

Yes, a permit is always required when installation or modification needs to be done to a storm drainage system that connects to a public storm system. You need to have the permit in hand before the project begins and ensure that city-specific drainage requirements are met.

Build It Right the First Time with Moss Utilities

There’s no question that undersized or poorly installed storm drainage systems can result in many preventable issues, such as flooding, foundation damage, and more. These issues are costly to repair, which is why it makes sense to install a reliable storm drainage system from the beginning.

At Moss Utilities, we are here to help, offering storm drainage infrastructure for a variety of properties, including commercial buildings, multi-family locations, data centers, and public works projects. We have a history of success on other large-scale projects across DFW.

Undersized or poorly installed storm drainage creates flooding, foundation damage, and regulatory exposure that costs far more to fix than to prevent. Moss Utilities designs and installs storm drainage system infrastructure for commercial, multi-family, data center, and public works projects across DFW.

Before your next project breaks ground, contact us at Moss Utilities for a storm drainage scope review. We’re always just a phone call away.