W200-18

Preface This is the first edition of CSA W200, Design of bioretention systems. It should be noted that this Standard, by itself, does not have the force of law unless it is officially adopted by a regulatory authority. Since regulatory authorities can adopt the Standard with certain exceptions or additional requirements, it is recommended that the regulatory authority of the relevant jurisdiction be consulted in order to establish the extent to which this Standard has been adopted. Where this Standard conflicts with regulatory requirements, the regulatory requirements take precedence. This project was made possible through the generous support of the National Research Council Canada as part of its Climate Resilient Buildings and Codes Infrastructure initiative. This Standard has been developed in compliance with StandardDetails Council of Canada requirements for National StandardDetails of Canada. It has been published as a National Standard of Canada by CSA Group. 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.