Changes

LID designs typically have specific grading requirements. Verifying depths and slopes is critical for the optimal performance of the facility. For example, if the design calls for a channel with a 1% slope, the channel may not function as designed if it has a 2% slope instead.  

LID designs typically have specific grading requirements. Verifying depths and slopes is critical for the optimal performance of the facility. For example, if the design calls for a channel with a 1% slope, the channel may not function as designed if it has a 2% slope instead.  

[[File:trimble unit.JPG|400px|thumb|right|Always confirm elevations throughout construction. (Photo source: CVC, 2022)]]

[[File:trimble unit.jpg|400px|thumb|right|Always confirm elevations throughout construction. (Photo source: CVC, 2022)]]

Excavation to the sub-grade will differ depending on whether the design is for a [[Bioretention: Variations|full infiltration, partial infiltration, or no infiltration LID system]]. If it’s a full infiltration or partial infiltration practice, the sub-grade should be as level as possible to promote even infiltration across the facility’s footprint.  For no infiltration designs,  excavate sub-grade slopes to the design grade in the direction of the underdrain, typically 1 to 2%.  

Excavation to the sub-grade will differ depending on whether the design is for a [[Bioretention: Variations|full infiltration, partial infiltration, or no infiltration LID system]]. If it’s a full infiltration or partial infiltration practice, the sub-grade should be as level as possible to promote even infiltration across the facility’s footprint.  For no infiltration designs,  excavate sub-grade slopes to the design grade in the direction of the underdrain, typically 1 to 2%.