[permaculture] Looking for good examples of the use of berms and swales & definition of each
paul.cereghino at comcast.net
Wed Jul 11 02:16:59 EDT 2007
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.
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.
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