BMP Monitoring Sites - Urban Drainage and Flood Control District
BMP Monitoring Sites - Urban Drainage and Flood Control District
BMP Monitoring Sites - Urban Drainage and Flood Control District
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UDFCD <strong>BMP</strong> MONITORING SITES<br />
Pervious Concrete Pavement<br />
◊ Lmax = maximum distance between cut-off<br />
membrane normal to the flow (ft)<br />
◊ So = slope of the base course (ft/ft)<br />
◊ D = depth of gravel base course (ft)<br />
Subdrain System<br />
When the pervious concrete pavement is located on<br />
NRCS Type D soils, when the Type B or C soil sub-base<br />
is to be compacted for structural reasons, or when an<br />
impermeable membrane liner is needed, install a<br />
subdrain system using HDPE pipe. Locate each<br />
perforated pipe just upstream of the lateral-flow cut-off<br />
barrier. Do not exceed 20-foot spacing. Use a control<br />
orifice sized to drain the pore volume of empty each cell<br />
in 6 hours or more.<br />
Design Area Ratio The design area ratio shall not exceed 2.0 (ratio =<br />
And Effective contributing impervious area/pervious pavement area).<br />
Imperviousness The interim recommendations for effective<br />
imperviousness are given in the Manual.
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