Revised 2017
This manual is support for civil engineers as well as
for landscape architects, urban planners, contractors,
stormwater and transportation agencies. Those who
use it should be familiar with stormwater management
concepts and calculation methods. This fifth edition
includes revised subbase thickness design tables developed
via full-scale load testing and mechanistic modeling
in 2014 by the University of California Pavement
Research Center. The revised tables, selected figures,
and ideas from this manual are also included in the
ASCE/ANSI national standard on PICP now in its final
stages at this writing. So be on the lookout for it. That
standard gives more in-depth information on PICP hydrologic
and hydraulic design. This manual has comprehensive
reading on construction and maintenance. The two should be read together.
As with the previous edition, this fifth edition is divided
into five sections. Section 1 provides an overview on
PICP. Section 2 provides criteria for selecting appropriate
sites and systems. Section 3 includes basics for
sizing storage and selecting base and subbase thicknesses.
Detailed inflow and outflow calculations can be
examined using ICPI’s Permeable Design Pro software
or other stormwater models. Calculations must be
done by qualified engineers familiar with hydrology
and hydraulics, as well as pavement structural design
using flexible pavement design concepts articulated by
the University of California Pavement Research Center
and by the American Association of State Highway and
Transportation Officials (AASHTO).