Step 1:

Enter the Square Feet of Drainage Area 1: (Ex. Roof)

Enter the Square Feet of Drainage Area 2: (Ex. Grass)

Step 2:

Choose the Coefficient of Runoff for Area 1:0.35 (Grass)0.40 (Sand)0.45 (Loam)0.50 (Gravel)0.60 (Clay)0.70 (Compact Gravel)0.800.91.0 (Concrete/Asphalt/Roof)

Choose the Coefficient of Runoff for Area 2:0.35 (Grass0.40 (Sand)0.45 (Loam)0.50 (Gravel0.60 (Clay)0.70 (Compact Gravel)0.80.91.0 (Concrete/Asphalt/Roof)

Step 3:

Choose the 25 Year Rainfall: (see rainfall map).0.50.7511.251.51.7522.252.52.753in/hr

Step 4:

Enter the depth of the gravel backfill beneath the Flo-Well:
(Dimension A) ft

Step 5:

Enter the thickness of the gravel backfill around the Flo-Well:
(Dimension B) ft

Step 6:

Press the Calculate button for results: