Changes

LID designs typically have very specific grading requirements. Verifying depths and slopes is critical for 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. Similarly, if the designs call for 1 metre of excavation from grade and only 90 cm are excavated, it will not have enough storage space to meet the design criteria. <br/>

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.  

 

Excavation to the sub-grade will differ depending on whether the design is for an infiltrating or a non-infiltrating LID system. If it’s an infiltrating practice, the sub-grade should be as level as possible to promote even infiltration across the facility’s footprint.  For non-infiltrating practices, excavate sub-grade slopes to the design grade in the direction of the underdrain, typically 1 to 5%.

 

As with all infiltrating LID practices, avoid compaction of sub-grade soils whenever possible. However, depending on the design and the local municipality, compaction of the sub-grade may be required for permeable pavement LIDs.

 

'''Construction steps'''

'''Construction steps'''

#Excavate from the rough grade to the finish grade using appropriate equipment. This is often done with hand tools.

#Excavate the final 100 mm, to the final design grade, using appropriate equipment. This is often done with hand tools.

#Confirm excavation depths and slopes using appropriate equipment (transit levels, global navigation satellite systems, etc.)

#Confirm excavation depths and slopes using appropriate equipment (transit levels, global navigation satellite systems, etc.)

'''Key inspection points'''

'''Key inspection points'''