Changes

#[[Post-construction]]

#[[Post-construction]]

Most LID practices work at the ground-level by routing stormwater flows from impervious surfaces into excavated or natural depressions or by allowing stormwater to pass through a traditionally impervious surface, as is the case with permeable pavements. These depressions are designed and constructed to the meet goals of the LID practice, which may be quality control, quantity control, or water balance restoration. Bioretention gardens, bioswales, rain gardens, enhanced grass swales, exfiltration systems, permeable pavements, and infiltration systems (chambers, trenches, and soakaways) all fall into this category.   

Most LID practices work at the ground-level by routing stormwater flows from impervious surfaces into excavated or natural depressions or by allowing stormwater to pass through a traditionally impervious surface, as is the case with permeable pavements. These depressions are designed and constructed to the meet goals of the LID practice, which may be quality control, quantity control, or water balance restoration. [[Bioretention]] gardens, [[bioswales]], [[rain gardens]], [[enhanced swales]], [[exfiltration trenches]], [[permeable pavements]], and infiltration systems (chambers, [[infiltration trenches|trenches]], and soakaways) all fall into this category.   

For this reason, Stages 1-2 and 5 of the LID construction process are fundamentally similar for all '''ground-level LID''' types. To illustrate, STEP's recommended processes for excavation do not differ depending on the practice type. Excavation is excavation, whether it is for a bioretention garden or a permeable pavement parking lot. On the other hand, stage 4 sub-tasks will vary substantially from LID type to LID type, since the construction processes for installing the surface of an LID practice will differ depending on whether the practice is vegetated or not. Some sub-tasks in stage 3 will also vary. For example, permeable pavements often require compaction of sub-surface storage layers. The following sections give a brief description of each over-arching stage and links to the page dedicated to each construction stage.

For this reason, Stages 1-2 and 5 of the LID construction process are fundamentally similar for all '''ground-level LID''' types. To illustrate, STEP's recommended processes for excavation do not differ depending on the practice type. Excavation is excavation, whether it is for a bioretention garden or a permeable pavement parking lot. On the other hand, stage 4 sub-tasks will vary substantially from LID type to LID type, since the construction processes for installing the surface of an LID practice will differ depending on whether the practice is vegetated or not. Some sub-tasks in stage 3 will also vary. For example, permeable pavements often require compaction of sub-surface storage layers. The following sections give a brief description of each over-arching stage, a list of sub-tasks for each stage, and links to the page dedicated to each main sequence construction stage.

'''Green roofs, blue roofs, and rainwater harvesting systems have specific construction sequences that differ from the main sequence described above. One day we will write guidance for these LID practices as well.'''

'''Green roofs, blue roofs, and rainwater harvesting systems have specific construction sequences that differ from the main sequence described above. One day we will write guidance for these LID practices as well.'''

==Finishing grades and surface layer installation==

==Finishing grades and surface layer installation==

This construction stage differs between LID practice types. The finishing grades and surface layer installation: vegetated LIDs page has guidance for vegetated LIDs, and the finishing grades and surface layer installation: permeable pavements has guidance for non-vegetated LIDs. In many cases the surface of infiltration systems will be traditional asphalt, concrete, or pavers; STEP does not provide guidance on installing non-permeable surfaces.  

This construction stage differs between LID practice type. The finishing grades and surface layer installation page has guidance for vegetated LIDs and non-vegetated LIDs (i.e., permeable pavements). In many cases the surface of infiltration systems will be traditional asphalt, concrete, or pavers; STEP does not provide guidance on installing non-permeable surfaces.

 

{| class="wikitable"

{| class="wikitable"

!Permeable pavements

!Permeable pavements

|-

|-

|*soil media installation and soil amendments

|*geotextile (if applicable)

| PP

| PP

|-

|-

|*finish grading

|*underdrain

| PP

| PP

|-

|-

|*large stone and riprap

|*impermeable liners

|PP

|PP

|-

|-

|*plant verification and installation

|*overflow

|PP

|PP

|-

|-

|*mulch placement

|*monitoring wells

|pp

|pp

|-

|-

|*stabilizing contributing drainage area and planting adjacent vegetation

|*storage reservoir

|PP

|PP

|}

|}