Flo-Well Calculator
Use the calculator below to determine the number of Flo-Wells you will need.
Step 1
Enter the length in feet of your drainage area.
Enter the width in feet of your drainage area.
Step 2
Select the surface of your Drainage Area.
Concrete
Asphalt
Roof Top
Gravel-Compact
Clay-Bare
Clay-Lt. Vegetation
Clay-Dense Vegetation
Gravel-Bare
Gravel-Lt. Vegetation
Gravel-Dense Vegetation
Loam-Bare
Loam-Lt. Vegetation
Loam-Dense Vegetation
Sand-Bare
Sand-Lt. Vegetation
Sand-Dense Vegetation
Grass Area
Step 3
Select the material used as backfill.
Gravel-Compact
Clay-Bare
Clay-Lt. Vegetation
Clay-Dense Vegetation
Gravel-Bare
Gravel-Lt. Vegetation
Gravel-Dense Vegetation
Loam-Bare
Loam-Lt. Vegetation
Loam-Dense Vegetation
Sand-Bare
Sand-Lt. Vegetation
Sand-Dense Vegetation
Grass Area
Step 4
Enter the diameter in feet of the backfill material
Step 5
Select the soil type under the Flo-Well.
Gravel-Compact
Clay-Bare
Clay-Lt. Vegetation
Clay-Dense Vegetation
Gravel-Bare
Gravel-Lt. Vegetation
Gravel-Dense Vegetation
Loam-Bare
Loam-Lt. Vegetation
Loam-Dense Vegetation
Sand-Bare
Sand-Lt. Vegetation
Sand-Dense Vegetation
Grass Area
Formula for number of Flow-Wells per Drainage Area:
Number of Flo-Wells to use per Drainage Area =
[Water Runoff Volume into Flo-Well] X Coefficient of Ground Under Flo-Well]
[Volume of Flo-Well (7.527ft
3
)] + Volume of Backfill Material]
Water Runoff Volume =
(Sq. Ft. Area X Coefficient of Runoff)
12
Volume of Backfill Material =
3.14/4 X (Diameter of Backfill Material
2
- Diameter of Flow-Well
2
) X
Depth of Flow-Well X (1-Coefficient of Runoff for Backfill Material)