Low Impact Development Manual for Michigan - OSEH - University ...

9. The maximum lateral slope of a filter strip is one
percent.
10. To prohibit runoff from laterally bypassing a strip,
berms and/or curbs can be installed along the sides
of the strip, parallel to the direction of flow.
Figure 7.50
A level spreading device (gravel-filled trench)
Figure 7.51
Concrete curb stop schematic
Table 7.15
Recommended Length as a Function of Slope, Soil Cover
Filter Strip Soil Type
Hydrologic Soil
Group
As shown in Figures 7.52–7.56, the recommended filter
strip length varies depending on the type of soil, the
type of vegetation, and the filter strip slope. Generally,
the more permeable the soil and/or the lower the slope,
the shorter the filter strip may be for equivalent stormwater
benefits.
Maximum Filter Strip Slope (Percent)
Turf Grass, Native
Grasses and Meadows
Planted and
Indigenous Woods
Sand A 7 5
Sandy Loam B 8 7
Loam, Silt Loam B 8 8
Sandy Clay Loam C 8 8
Clay Loam, Silty Clay, Clay D 8 8
LID Manual for Michigan – Chapter 7 Page 293