*''S<sub>0</sub>'' is the longitudinal slope ratio
*''S<sub>0</sub>'' is the longitudinal slope ratio
*''n'' is Manning's 'n' (between 0.012 and 0.016 for concrete, depending on surface treatment), and
*''n'' is Manning's 'n' (between 0.012 and 0.016 for concrete, depending on surface treatment), and
−
*''S<sub>x</sub>'' is the cross slope ratio}}
+
*''S<sub>x</sub>'' is the cross slope ratio (typically between 0.015 and 0.04)}}
−
Where the inlet width is constrained or the intention is to capture only a proportion of the flow, the ratio of flow entering the curb inlet may be calculated::
+
Where the intention is to capture only a proportion of the flow, the ratio of flow entering the curb inlet may be calculated::
*''R<sub>c</sub>'' is the proportion of flow entering the curb cut, and
*''R<sub>c</sub>'' is the proportion of flow entering the curb cut, and
*''W'' is the available curb cut width (m)}}
*''W'' is the available curb cut width (m)}}
+
+
Where the curb cut width is constrained and a greater flow into the BMP is desired, the effective cross slope may be increased by adding a small depressed section.