Eugene Stormwater Facility Calculator Project Name: Bushnell University Duke Commons <br />Basin: 3 <br />Instructions:Date: 5/1/2026 <br />1. Choose Facility Type <br />2. Choose shape <br />3. Complete information in highlighted cells <br />Facility Planter <br />Grassy <br />Shape Rectangular Below-Grade <br />Bottom Area:325 sf 40 <br />Bottom Width:16 ft 12 <br />Vertical Sides4 0.40 <br />Storage Depth:6in <br />Growing Media:18 in 1.00 <br />2.00 <br />Surface Storage Capacity 163 cf <br />Infiltration Area 325 sf <br />GM Infiltration Rate 2.5 in/hr <br />Infiltration Capacity (avg)0.019 cfs <br />Results <br />SURFACE CAPACITY <br />Recurrance <br />Interval <br />Peak Flow <br />(cfs) <br />Volume <br />(cf) <br />Meets <br />Infiltration? <br />WQ 0.0188 838 Filtration Only <br />2-Yr 0.1810 2,187 <br />5-Yr 0.2099 2,580 <br />10-Yr 0.2617 3,268 N/A <br />25-Yr 0.3048 3,850 <br />50-Yr 0.3539 4,507 <br />100-Yr 0.3826 4,900 <br />WATER QUALITY EVENT PASS ROCK CAPACITY N/A <br />Rock Capacity <br />N/A <br />N/A <br />N/A <br />N/A <br />Impermeable Liner <br />10-Yr Infiltration <br />Volume (cf): <br />N/A <br />74% <br />N/A <br />N/A <br /> 800 Willamette Street, Suite 400 Eugene, OR 97401 541.684.4902 kpff.com