This document is the Retention/Detention section of the ADS Drainage Handbook. It gives an overview of Retention/Detention Systems.

The section begins by giving information about stormwater management including how to manage stormwater runoff, the best way to capture stormwater, the different between stormwater retention and stormwater detention and the various shapes, sizes and materials used in stormwater retention and detention.

Part of the section gives the various subsurgace retention/detention products and systems and choosing the correct retention/detention system. When designing a retention/detention system the section gives information about checking regulations, calculating storage capacity, determining system layout, selecting products, evaluating maintenance requirements and selecting fittings and accessories.

The section also describes design aids, best management practices, technical assistance and other technical resources.

Figures within the section include: Retention/Detention System Selection Guidelines, Typical Retention/Detention Cross Section, Triple Component Retention/Detention Manifold with Size on Size Connections, Retention/Detention Clean-Out Ports, Typical Catch Basin (Non-Traffic Areas Only), Water Quality Unit, Typical End Cap Section, Roof Drain with Wye Cleanout, Roof Drain with Tee Cleanout and ADS Retention/Detention System Design Tool.

The section also includes three tables: ADS Retention/Detention Systems Features and Benefits, Storage Capacities of N-12 Pipes and Perforation Patterns.