Drainage Metal

100-300 Swale rock
Used for swales or sumps

20/40 Drainage:
This is used for septic drainage fields, behind retaining walls, muddy roads where a thin skim will provide traction, around farm sheds and also in cattle yards


30/60 and 40/90 Drainage
These are cheaper versions of 20/40 drainage. They are not as clean and are larger in diameter. They are used for farm and forestry roads, and skid sites which have heavy traffic. This is also used as a ground cover for landscaping.


50/150
This is for roadside swales and is sometimes used for gabion baskets.