# calculateUnitDrawdown

> Unit drawdown s/Q (h/m²). Throws RangeError when flowRate is zero.

> **calculateUnitDrawdown**(`drawdown`, `flowRate`): `number`

Unit drawdown s/Q (h/m²). Throws RangeError when flowRate is zero.

## Parameters

### drawdown

`number`

### flowRate

`number`

## Returns

`number`