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*'''Base Construction''': Aggregate should be placed in 100 mm to 150 mm lifts and compacted with a minimum 9 ton steel drum vibratory roller. A light weight deflectometer may be used to test compaction level of open graded stone and compare to specifications.
*'''Base Construction''': Aggregate should be placed in 100 mm to 150 mm lifts and compacted with a minimum 9 ton steel drum vibratory roller. A light weight deflectometer may be used to test compaction level of open graded stone and compare to specifications.
*'''Weather''': Porous asphalt and pervious concrete require a specific temperature range to set properly and the setting time can be several days.<ref>City of Portland. 2004. Portland Stormwater Management Manual. Prepared by the Bureau of Environmental Services (BES). Portland, OR.</ref>
*'''Weather''': Porous asphalt and pervious concrete require a specific temperature range to set properly and the setting time can be several days.<ref>City of Portland. 2004. Portland Stormwater Management Manual. Prepared by the Bureau of Environmental Services (BES). Portland, OR.</ref>
==Inspection and Maintenance==
Permeable pavements require regular inspection and maintenance to ensure proper functioning. The limiting factor for permeable pavements is clogging of the surface course or joint filler between pavers. As these start to fill, the trapped sediment becomes finer and finer until they eventually become clogged. Ideally, signs should be posted on the site identifying permeable pavement. This can also serve as a public awareness and education opportunity. See: [[Permeable paving: Maintenance|Permeable pavement: Maintenance]]
==Life Cycle Costs==
Initial construction costs for permeable pavements are typically higher than conventional asphalt pavement surfaces, largely due to the price of the surface course and thicker aggregate base needed for stormwater storage. However, the cost difference is reduced or eliminated when total life-cycle costs, or the total cost to construct and maintain the pavement over its lifespan, are considered. Other potential savings and benefits include reduced need for storm sewer pipes and other stormwater practices, less developable land consumed for stormwater treatment, and ancillary benefits (improved aesthetics and reduced urban heat island effect). These systems are especially cost effective in existing urban development where parking lot expansion is needed, but there is not sufficient space for other types of BMPs. They combine parking, stormwater infiltration, retention, and detention into one facility. See also: [[Cost analysis resources]]
==Performance==
{|class="wikitable"
|+Ability of Permeable Pavements to Meet Stormwater Management Objectives
|-
!BMP
!Water Balance
!Water Quality
!Erosion Control
|-
|'''Permeable pavement with no underdrain'''
|Yes
|Yes-size for water quality storage requirement
|Partial-based on available storage volume and native soil infiltration rate
|-
|'''Permeable pavement with underdrain'''
|Partial-based on available storage, native soil infiltration rate and if a flow restrictor is used
|Yes-size for water quality storage requirement
|Partial-based on available storage, native soil infiltration rate and if a flow restrictor is used
|-
|'''Permeable Interlocking Pavements'''
|No-some volume reduction occurs through evaporation
|Yes-size for water quality storage requirement
|Partial-based on available storage volume and if a flow restrictor is used
|}
==Landscaping and grading==
==Landscaping and grading==