Types of stormwater facilities
Stormwater flow control facilities
A flow control facility is designed to capture, store, and slowly release stormwater runoff downstream or into the ground. These facilities include:
- Underground tanks
- Infiltration systems
How do flow control facilities work?
There are two types of flow control facilities, detention and retention.
Detention ponds store stormwater runoff and slowly release it downstream. In some cases, detention ponds are combined with water quality treatment ponds. Those ponds store some water on a permanent basis.
Retention, or infiltration, ponds collect stormwater and allow water to soak into the soil. This process helps recharge groundwater. Infiltration tanks or pipes are located underground and release water into the soil to be absorbed.
Underground tanks and vaults function like detention ponds. Rainwater from storms are stored in these facilities and slowly released downstream. Tanks and vaults are often located in places like a road right-of-way, parking lots, and easement on private property.
Water quality facilities
Water quality facilities protect water quality by removing pollutants. These facilities are often combined with flow control facilities. Water quality facilities include:
- Vegetated swales
- Settling ponds or vaults
- Sand filters
- Compost filters
- Oil-water separators
- Constructed wetlands