Junction Boxes


Efficient and Effective Transfer of Stormwater

Consistent Quality

Consistent quality and dimensional accuracy are ensured with factory production.

Optional Pollution Controls

Pollution control options can include debris inserts, oil dams, oil-stop valves, and backflow prevention.

Watertight Performance

Watertight performance is guaranteed with tight tolerances and gasketed joints.

Quick Installation

We manufacture our junction boxes in a quality-controlled environment, rather than on site, for quick installation and minimal site preparation.


In stormwater management, a junction box serves as a connection point for multiple pipes within a stormwater system. Its primary function is to facilitate the efficient and effective transfer of stormwater from one pipe to another, or from one drainage area to another.

Typically located underground, ParkUSA junction boxes are constructed with durable precast concrete, which can withstand the weight of surrounding soil and the pressure of stormwater flow. They are designed with multiple inlet and outlet pipes that connect to the surrounding stormwater system.

Junction boxes aid in preventing flooding and erosion by directing the flow of stormwater away from sensitive areas and into appropriate drainage channels. They are commonly used in commercial and residential developments to manage stormwater runoff from rooftops, driveways, and other impervious surfaces. Junction boxes streamline the design and construction of stormwater systems, enhancing their efficiency and cost-effectiveness.

How It Works

Junction boxes are used to collect and manage stormwater runoff from impervious surfaces like roadways and parking lots. Inlet pipes direct the stormwater to the junction box where it is temporarily stored before being safely discharged into the drainage system. Our junction boxes can also improve water quality by filtering out debris and pollutants from the runoff. Periodic maintenance is performed to remove the captured materials and prevent blockages.

The ParkUSA precast concrete junction boxes consist of several components that work together to efficiently collect and convey surface runoff in stormwater management systems.


About the Precast Junction Box

Model JB serves as a central point for connecting multiple stormwater pipes or providing valve access to control the flow and direction of runoff. The junction box is made of precast concrete and consists of a square or rectangular box with an open top, a cast-in steel frame, and a solid steel cover. The perimeter walls contain thin-wall knockouts for connecting pipes for stormwater conveyance. The junction box is available in different sizes and configurations to meet most application demands and municipal codes.


ParkUSA’s junction boxes are versatile structures used to collect, transfer, and manage stormwater runoff.

Parking Lots

Junction boxes serve as a central point of connection for multiple pipes, allowing for the efficient transfer of stormwater to the surrounding drainage system.

Roadway and Highway Drainage

Junction boxes are also used to manage stormwater runoff in roadways and highways. They collect and transfer stormwater to the drainage system, helping to prevent flooding and erosion.

Commercial and Residential Developments

Junction boxes can manage stormwater runoff from rooftops, driveways, and other impervious surfaces. They help to control the volume and velocity of stormwater, reducing the risk of flooding and erosion.

Stormwater Retention and Treatment

Junction boxes can be used in stormwater retention and treatment systems to collect and treat stormwater before releasing it into the drainage system.

Specs & Docs


Junction Box (Model JB – 12″ thru 48″)


Junction Box (Model JB – 48″ thru 84″)


Junction Box (Model JBC – 12″ thru 84″)


Junction Box (Model JBE – 48″ thru 84″)

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