Changes

[[File:Gravel.jpg|thumb|medium sized granular, free from fines]]

[[File:Gravel.jpg|thumb|medium sized granular, free from fines]]

In [[bioretention]] systems a choking layer of ≥ 100 mm is the recommended method to prevent migration of finer [[filter media]] into an underlying reservoir of [[Reservoir gravel|coarse aggregate]].

In [[bioretention]] systems a choking layer of ≥ 100 mm is the recommended method to prevent migration of finer [[filter media]] into an underlying reservoir of [[Reservoir gravel|coarse aggregate]].

These same mid sized granular materials are recommended for use in [[Stormwater planter]] underdrains.  

These same mid sized granular materials are recommended for use in [[Stormwater planter]] underdrains and may be useful in the fine grading of foundations courses for [[permeable paving]].

Suitable materials include:

Suitable materials include: