25 October 2004
take advantage of the biological and chemical processes of the plant soil complex have
shown tremendous potential in stormwater management. These natural systems are
easy to design, construct, and maintain, even though the naturally occurring filtering and
treatment processes may be quite complex and multidimensional. Benefits of using
these small-scale and simplified systems (such as soil amendments, landscaping, or re-
vegetation) include the reduced need for costly large-scale construction projects (such
as underground concrete vaults or proprietary filters).
Figure 5-2 illustrates the range of biological and chemical processes that
have been documented to occur in a bioretention cell. The bioretention cell is a
landscape area constructed of specialized soil and plants that can effectively absorb
and treat urban runoff.
Figure 5-2. Biological and Chemical Processes that Occur in a Bioretention Cell
Source: Prince George's County, Maryland Department of Environmental Resources (PGDER), 2000.
Utilize Multifunctional Landscape, Buildings and Infrastructures. There
are a wide variety of LID practices available. The primary criterion in selecting LID
practices is that the design of the component contributes to satisfying the design and
regulatory objectives. Design features are often multifunctional and satisfy multiple
objectives. The development of vegetated roofs is a good example. A vegetated roof