W200-18

1 Scope 1.1 General This Standard provides requirements and recommendations for the design of bioretention systems intended for the management of urban stormwater runoff. 1.2 Bioretention systems covered by this Standard The following types of bioretention systems are covered by this Standard: a) bioretention with underdrain and with no underdrain; b) biofilters (impermeable liner); and c) bioretention planters and bioretention bump-outs (curb extensions). 1.3 Bioretention systems not covered by this Standard The following sub-types of bioretention systems are not covered by this Standard: a) bioswales; b) tree trenches or pits; and c) rain gardens. 1.4 Terminology In this Standard, “shall” is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the Standard; “should” is used to express a recommendation or that which is advised but not required; and “may” is used to express an option or that which is permissible within the limits of the Standard. Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material. Notes to tables and figures are considered part of the table or figure and may be written as requirements. Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.