Stormwater BMP Learning Center

Welcome to the Exact Stormwater Management Learning Center. This resource is designed to help property managers, HOA directors, commercial property owners, and contractors understand the stormwater best management practices (BMPs) installed on their properties. Each guide below explains what a BMP is, how to inspect it, how to maintain it, and how it gets installed.

If you manage a commercial property, an HOA community, or a development site, you likely have one or more of these systems on your property. Understanding how they work and what they need is the first step toward keeping them compliant and functional.

Surface BMPs

• Bioretention and Rain Gardens

  Nature-inspired systems that use engineered soil and vegetation to capture and treat stormwater runoff. Common on commercial and residential sites as landscaped depressions designed to filter pollutants from rainwater.

• Permeable Pavements

  Paving systems designed to allow water to pass through the surface and infiltrate into a stone reservoir below. Used for driveways, parking lots, sidewalks, and patios where traditional pavement would create runoff.

• Infiltration Basins

  Systems designed to collect rainwater from impervious surfaces and infiltrate it through the soil. A broad BMP category that includes many system types focused on returning stormwater to the ground.

Ponds

• Wet Ponds

  Permanent pools of water designed to treat stormwater through natural sedimentation and biological processes. Wet ponds maintain water year-round and provide both flow control and water quality treatment.

• Dry Ponds / Extended Detention Ponds

  Stormwater detention facilities that temporarily hold runoff during storms and drain completely between rain events. Primarily designed for flood control and peak flow reduction.

• Outlet Control Devices

  Structures that regulate the rate at which stored water is released from detention and retention facilities. Critical components of wet ponds, dry ponds, and underground detention systems.

Underground Systems

• Underground Detention

  Systems installed beneath the ground surface to store stormwater runoff and release it at a controlled rate. Allow developers to manage runoff without dedicating surface area to a pond.

• Sand Filters

  Compact underground treatment systems that remove pollutants by passing stormwater through a sand filtration layer. Effective in urban settings where space is limited.

Manufactured Treatment Devices

• Water Quality Separators

  Devices that use gravity, baffles, or swirling flow patterns to physically separate sediment and debris from stormwater. Includes vortex separators and hydrodynamic separators.

• Water Quality Filters

  Systems that pass stormwater through manufactured filter cartridges or specialized media to remove fine pollutants. Used as standalone treatment or in combination with other BMPs.
  

Not Sure What You Have?

If you manage a property with a stormwater system but are not sure what type it is, you are not alone. Many property managers inherit these systems without documentation. Here are a few clues that can help:

If you see a landscaped depression with plants and mulch: You likely have a bioretention facility or rain garden.

If you see a pond with water in it year-round: That is probably a wet pond.

If you see a basin that fills during rain but is dry otherwise: You likely have a dry pond or extended detention pond.

If you have manholes or access hatches in your parking lot: You may have an underground detention system or a manufactured treatment device.

If you have pavers with visible gaps or porous-looking concrete: That is a permeable pavement system.

Still not sure? Contact Exact Stormwater and we will help you identify your system and determine what maintenance it needs.