permaculture

[Paul Cereghino <paul.cereghino@comcast.net>]

These are all 'common names' and refer as much to function as to structure.

Berm is a very broad term, a linear earthen feature above grade.  The 
term berm is common in landscape architecture with the function of 
creating noise abatement or implied enclosure. Berm implies earthen 
structure... "sugar levee" is local slang for a levee made of native 
material without rock to add stability (a berm like levee?).. Similar to 
berm is a dike, but dike implies that goal is to resist tidal 
inundation, where levee suggests riverine inundation, both have 
geotechnical functions and design implications, like dam.

While berm is an outie, swales are innies,  A swale is a linear feature 
below grade... implies low gradient, water absorbtion function, ditch 
suggests the goal is drainage, suggests steeper walls.  drain and ditch 
systems , roadside ditches, etc...  berm, swale and ditch both imply 
human made, as opposed to stream, arroyo, gully, or more technically, 
alluvial channel.  However some refer to natural levees formed by 
alluvial sediment deposition next to a channel.  Ha ha is a ditch with 
the function of animal exclusion -- structure depends on the animal 
(guinea pig to elephant)
dam impounds surface water, has spillway etc..  a berm can be a dam, but 
not all dams are berms.

Curious to see if there is any divergence from these concepts.  Sorry, 
no pictures.  I am slowly designing a miniature ditch/berm/dam swale 
system for our place... I'll put it on the wiki when I get a chance.

Paul Cereghino

Lawrence F. London, Jr. wrote:

> I'm looking for good examples of the use of berms and swales & 
> definition of each.
> - also how they differ from dams, ditches and ha ha's.
>
> LL
>