Best Management Practice

Underground Retention/Detention

What is underground retention/detention?

Underground stormwater retention and detention systems collect and hold rainwater in substantial pipes or subsurface structures. Stormwater initially enters the system via a riser pipe linked to a catch basin or curb inlet and then proceeds into a sequence of chambers or compartments for storage. This collected runoff remains retained throughout the storm, with the option for controlled release into surface waters through an outlet pipe.

Underground retention/detention systems are commonly incorporated within "treatment trains," which comprise multiple stormwater Best Management Practices (BMPs) designed to offer both stormwater treatment and storage capabilities.

Why use underground detention?

Underground stormwater retention and detention provides more use of the land, which gives more opportunity for building and construction above land. Underground usage increases public safety and 


Captures stormwater runoff

Easily and quickly installed 

Durable for many years 

Efficient use of urban space 

Safer for community members


Difficult to maintain and clean 

Don't provide water quality benefits 

May contribute to water contamination

For more resources click the links below!

Check out our social media below





Copyright © 2024 Protect Wisconsin Waterways