# Groundwater level formula (Water Overlay)

Groundwater level is calculated per cell.

Where:

- = The height (column) of the saturated zone.
- = The amount of water in the saturated zone. The height of the water column if the equivalent amount of water was placed on the surface.
- = The WATER_STORAGE_PERCENTAGE of the underground terrain type, used here as a fraction.
- = The groundwater level, relative to datum. Also known as the watertable.

- = The surface height in the cell, relative to datum.
- = The GROUND_BOTTOM_DISTANCE_M (effectively available height in the underground model).

## Related

The following topics are related to this formula.

- Features
- Groundwater
- Formulas
- Underground flow formula
- Underground evaporation formula
- Surface infiltration formula
- Underground infiltration formula
- Underground seepage formula
- Models
- Surface model
- Underground model
- Evaporation model
- Infiltration model