---
title: "Filtration"
canonical: "https://help.innovyze.com/space/infodrainage2020v2/16417356/Filtration"
format: markdown
---
**Filtration Control** represents a flow through a filter bed.

The following equation is used:

![image](media://2b9c6ad5-d7be-4a60-9a38-c23fd551b33a)

where

Q = Discharge

A = Area

K = Permeability Coefficient / Safety Factor

d = Filter depth

h = Water depth


> ℹ️ **Note**
> ℹ️ 
> ℹ️ The analysis will considers the head based on downstream conditions


## Specification  


**Permeability Coefficient** - The rate at which water stored in the stormwater control percolates into the filter medium within the structure.  

**Safety Factor** - The required safety factor.

**Bed Depth** - The depth of the planting soil bed.

**Area** - The surface area of the filter bed.

**Invert Level** - The invert level of the outlet.

![image](media://bf68a08e-08a9-4d6b-8a7a-92970ec18282)