Swales and berms – urban Permaculture farm in the making
Using swales, (shallow, broad and vegetated channels about 30 to 40cm wide in this instance) designed to store and/or convey runoff and remove pollutants. The excess soil from the digging the swale (trench) was used to create a ‘berm’ (A berm is a level space, shelf, or raised barrier separating two areas).
Advantages of swales and berms
• Easy to incorporate into landscaping
• Good removal of urban pollutants
• Reduces runoff rates and volumes
• Low capital cost
• Maintenance can be incorporated into general landscape management
• Pollution and blockages are visible and easily dealt with.
The word berm originates in the Middle Dutch and German berme and came into usage in English via French.