Stormwater wetlands are similar in design to stormwater ponds and mainly differ by their variety of water depths and associated vegetative complex. They require slightly more surface area than stormwater ponds for the same contributing drainage area. Stormwater wetlands are constructed stormwater management practices, not natural wetlands. Like ponds, they can contain a permanent pool and temporary storage for water quality control and runoff quantity control.
Benefit | Effectiveness | Notes |
---|---|---|
Water quality | Primary benefit is retention of sediment; may export phosphorus if not designed and maintained properly. | |
Water quantity/supply | Rate control benefit. | |
Energy savings | ||
Climate resiliency | Provides some rate control. Impacts on carbon sequestration are uncertain. | |
Air quality | ||
Habitat improvement | Use of perennial vegetation and certain media mixes promote invertebrate communities. | |
Community livability | Aesthetically pleasing and can be incorporated into a wide range of land use settings. | |
Health benefits | ||
Economic savings | Generally provide cost savings vs. conventional practices over the life of the practice. | |
Macroscale benefits | Individual practices are typically microscale, but multiple practices, when incorporated into a landscape design, provide macroscale benefits such as wildlife corridors. | |
Level of benefit: ◯ - none; ◔ - small; ◑ - moderate; ◕ - large; ● - very high |
Maximizing specific green infrastructure (GI) benefits of bioretention practices requires design considerations prior to constructing the practice. While site limitations cannot always be overcome, the following recommendations maximize the GI benefit of bioretetnion.