Symbols

• A - watershed area
• AB - total allowable drainage area to buffer
• AC - natural area conserved
• AD - area disconnected
• A_r - filter bed area
• A_s - surface area, sedimentation basin
• BM_PRE - BMP removal efficiency for total phosphorus
• C - flow–weighted mean concentration of the pollutant in urban runoff
• Ca - calcium
• CaCl₂ - calcium chloride
• Cl - chloride
• CMA - calcium magnesium acetate
• V_cp-ED - extended detention of the 1–year post–development runoff
• Cu - copper
• DA - % Served fraction of the drainage area served by the BMP
• d_f - depth of filter bed
• fc_soil - infiltration rate
• FCN - free cyanide
• Fe - iron
• h_f - head above filter bed
• Hg - mercury
• I - impervious cover
• I_a - initial abstraction
• IC - percent new impervious cover
• I_post - post–development site imperviousness
• K - coefficient of permeability
• KAc - potassium acetate
• KFo - potassium formate
• L - pollutant loading
• L_post - average annual load of total phosphorus exported from the post–development site
• L_pre - average annual load of total phosphorus exported from the site prior to development
• LR - annual total phosphorus load removed by the proposed BMP
• Mg - magnesium
• MgCl₂ - magnesium chloride
• N - nitrogen
• Na - sodium
• NaCl - sodium chloride
• NH₃ - ammonium
• NO_x - nitrogen oxides
• P - precipitation depth
• P - phosphorus
• P_j - fraction of rainfall events that produce runoff
• Q_f - extreme flood storage volume
• Q_i - peak inflow discharge
• Q_o - peak outflow discharge
• Q_p10 - overbank flood control storage rate
• Q_p100 - extreme storm control storage rate
• q_p - water quality peak discharge
• q_u - unit peak discharge
• r - volume of stormwater runoff
• R_ea - recharge area requiring treatment
• R_ev - recharge volume
• RR - pollutant removal requirement
• R_v - volumetric runoff coefficient expressing fraction of rainfall that is converted to runoff
• S - soil specific recharge factor
• t_c - time of concentration
• t_t - time to drain filter bed
• V_cp - channel protection volume
• Vp₁₀ - overbank flood control storage volume
• Vp₁₀₀ - extreme storm control storage volume
• V_pp - permanent pool volume
• V_r - rainfall runoff volume
• V_re - recharge volume
• V_s - snowmelt runoff volume
• V_t - total volume
• V_ts - total storage volume
• V_v - volume of voids
• V_wq - water quality volume
• V_wq ED - extended detention water quality volume
• Zn - zinc