How to go green by 2013

Porous pavers being laid to complete a stormwater plaza in Indianapolis.

TABLE 1/Per-unit control values Figures based on managing 80% to 90% of annual runoff volume in well-drained soils or poorly drained soils with underdrains .

TABLE 2/Installation unit costs Based on data from 29 suburban, urban, and green space retrofits in Indianapolis and Columbus, Ohio; the Center for Watershed Protection's Urban Stormwater Retrofit Practices Manual v1.0; Water Environment Research Foundation's BMP and LID Whole Life Cost Models v2.0 report; the Center for Neighborhood Technology's Green Values Calculator; and RS Means Site Work & Landscape Cost Data 2009, 28th Ed. Visit for direct links to these tools.

TABLE 3/Costs per square foot of impervious surface managed Dividing the installation cost (Table 2) by the area managed (Table 1) yields the budget manager's Holy Grail: C/I.


Figure 1. BMP annual runoff removal effeciencies for varying soil infiltration rates

Figure 2. Cost efficiency relative to intensity of application

Urban residential retrofit (no underdrains)

Downtown commercial retrofit (with underdrains)

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