Swales and existing plantings

Hi Everyone!

I am wondering if people have any advice on adding swales near existing plantings - land is a slope, down to a canyon.   It is very similar to this: http://www.thesurvivalgardener.com/establishing-high-desert-food-forest/
except I get a bit more water :)

We have raspberries, fern bush, vibernum, etc and we were pondering putting in some swales near them to catch some more water and hopefully keep the dirt from washing away so much.

I was thinking of putting them upslope from the existing plants and he thought we should put them downslope.  Or perhaps we should do both?  And, sizes? a foot across and about a foot down?  as wide as the planting? Our slope is perhaps 10 and 15%, depending on where in the yard. Some places we might have to build up for a swale rather than dig down since there is tuff.  

Thoughts?

Sandy

Use fishscale pattern of smaller swales to work around existing plantings. As a general rule start water catchment at the top and work down.

Your in high desert, I would think shallow and wide swells would be the way. Maybe remove 8-10"down and 3' wide  from around existing plantings, berming on the downslope. which makes rain gardens for existing plantings. Just make sure you have an overflow spot that allows the water to overflow over a 4' square level area or you will get erosion. Several good books I will give you some titles when I get to my library.