Changes

==Overview==

==Overview==

Given that [[Bioretention]] is a widely used name and a general "catch-all" term for most vegetated LID practices that temporarily store stormwater runoff in depressed planting beds there are a number of configurations of the feature that can be used in various contexts and environments. Depending on native soil infiltration rate and physical constraints, the facility may be designed without an [[underdrain]] for [[Bioretention: Full infiltration|full infiltration]], with an underdrain for [[Bioretention: Partial infiltration|partial infiltration]], or with an impermeable [[liner]] and underdrain for [[Stormwater planters|no infiltration/filtration only]] (i.e., [[stormwater planters]] or biofilter) design. STEP has prepared life cycle costs estimates for each design configuration, based on a 2,000 m² asphalt drainage area, runoff control target of 25 mm depth and 72 hour drainage period, for comparison which can be viewed below. To generate your own life cycle cost estimates customized to the development context, design criteria, and constraints applicable to your site, access the updated [https://sustainabletechnologies.ca/lid-lcct/ LID Life Cycle Costing Tool (LCCT) here].

Given that [[Bioretention]] is a widely used name and a general "catch-all" term for most vegetated LID practices that temporarily store stormwater runoff in depressed planting beds there are a number of configurations of the feature that can be used in various contexts and environments. Depending on native soil infiltration rate and physical constraints, the facility may be designed without an [[underdrain]] for [[Bioretention: Full infiltration|full infiltration]], with an underdrain for [[Bioretention: Partial infiltration|partial infiltration]], or with an impermeable [[liner]] and underdrain for [[Stormwater planters|no infiltration/filtration only]] (i.e., a [[stormwater planters]] or biofilter) design. STEP has prepared life cycle costs estimates for each design configuration, based on a 2,000 m² asphalt drainage area, runoff control target of 25 mm depth and 72 hour drainage period, for comparison which can be viewed below. To generate your own life cycle cost estimates customized to the development context, design criteria, and constraints applicable to your site, access the updated [https://sustainabletechnologies.ca/lid-lcct/ LID Life Cycle Costing Tool (LCCT) here].

==Design Assumptions==

==Design Assumptions==

Additional components include an [[underdrain]] to remove excess water and soil additives to enhance [[Nutrients|pollutant removal]]. <br>

Additional components include an [[underdrain]] to remove excess water and soil additives to enhance [[Nutrients|pollutant removal]]. <br>

Design and operation and maintenance program assumptions used to generate cost estimates are based on tool default values and the following STEP recommendations:

Design and operation and maintenance program assumptions used to generate cost estimates are based on tool default values and the following STEP recommendations:

* Native soil infiltration rates for Full, Partial and No Infiltration Design scenarios were assumed to be 20 mm/h, 10 mm/h and 2 mm/h, respectively, and a safety factor of 2.5 was applied to calculate the design infiltration rate.  

* Native soil infiltration rates for Full, Partial and No Infiltration Design scenarios were assumed to be 20 mm/h, 10 mm/h and 2 mm/h, respectively, and a safety factor of 2.5 was applied to calculate the design infiltration rate.