ABSTRACT
Surface Infiltration and Runoff .......................................................................... 122 Surface Infiltration Rate ........................................................................ 122 Runoff Coefficient .................................................................................. 125 Runoff Velocity and Travel Time .......................................................... 127 Runoff Observations at Symphony Square, Austin, Texas .................... 128
Disposition of Water below Pavement Surface .................................................. 129 Storage in Pavement Reservoir .......................................................................... 131
Storage Capacity .................................................................................... 131 Reservoir Configuration for Effective Storage ...................................... 132 Allowable Ponding Time ........................................................................ 135
Reservoir Discharge through Perforated Pipe .................................................... 136 Reservoir-Limited Discharge.................................................................. 137 Observations in Nottingham and Wheatley, England ............................ 140
Infiltration into Subgrade.................................................................................... 142 Soil Infiltration Rate .............................................................................. 143 Infiltration Ponding Time and Reservoir Thickness .............................. 145 Lateral Discharge Following Partial Infiltration .................................... 146 Subsurface Disposition of Infiltrated Water .......................................... 148 Watershed Discharge of Infiltrated Water .............................................. 150 Where Not to Infiltrate Stormwater........................................................ 152
Water-Quality Treatment .................................................................................... 152 Constituents in Pavement Stormwater.................................................... 154 Capture of Solids and Attached Metals .................................................. 155
Observations in Rezé, France ...................................................... 156 Observations in Nottingham, England.......................................... 157 Observation in Weinsberg, Germany ............................................ 158 Observations in the Netherlands .................................................. 158
Biodegradation of Oil ............................................................................ 159 Supplemental Treatment by Subgrade Infiltration ................................ 160
The Importance of Small Storms ...................................................................... 161 Frequency of Small Storms .................................................................... 161 Cumulative Rainwater Infiltration .......................................................... 161
Trademarks ........................................................................................................ 164 Acknowledgments .............................................................................................. 165 References .......................................................................................................... 165
Given the large area that pavements occupy, the volume of drainage water that pavements control is vast. What happens to that water is a question vital to the welfare of people, and is one of the driving forces behind the increasing application of porous pavement materials. This chapter reviews the types of hydrologic effects that porous pavements can have and the characteristics they can be given to bring about those effects.
