permaculture

["Steve Bonney" <sustainableearth.steve@verizon.net>]

>We just dug some post holes after a heavy rain...and >was surprised to see
that the soil from just a few inches
>down was so dry.

Frank, this sounds like the same problem as my farm --
low infiltration rate. Managed intensive grazing is the best
method that I know for increasing this. Ideally, water should not be running
off in high volumes. Higher percentage of organic matter is the key to
better infiltration.

You can use a series of ponds, but you do not want
water flowing over the dams. Like John said, it will wash
away the dam. You could use overflow pipes or concrete spillways.

If water converges into a single gulley, you could divert
the water higher up. Typically a key line is identified as
the line where the land changes from convex to concave.
It is here that water tends to collect, therefore can be
diverted laterally by opening the soil with a key line plow
or subsoiler.

I am intercepting water before it hits the steep slopes of
my forested land. I am building swales and planting bald
cypress and basket willow in them to take up water and
transpire it.
Steve

Steve Bonney
Sustainable Earth
  a not-for-profit membership organization dedicated to the
  development of sustainable family farming systems
  and local food systems
100 Georgton Ct.
W. Lafayette, IN 47906
(765) 463-9366
----- Original Message -----
From: <FranksFarm@aol.com>
To: "permaculture" <permaculture@franklin.oit.unc.edu>
Sent: Saturday, December 22, 2001 7:47 AM
Subject: Re: Water Ponding/Management


> Good day,
>
> John S. as always makes some interesting observations on pond locations,
etc.
>
> I've read some of the key line stuff but this city fella is still
confused:)
>
> Here's my comments.
>
> <<Ideally ponds go on broader areas of ridges and/or saddles, or as
> nearly as possible, where it's flatter and easier to build a stable
> pond with good work/volume ratio.>> Hmmm....on my land there are several
> broad, and long ridges. However water seems to gather and flow in series
of
> drains that wind down hills in S shaped curves. Drains seem for the most
part
> at the confluence of two adjacent slopes. And sometimes drains from other
> slopes converge.
>
> At times with heavy rainfall there can be a good volume of flowing water
> coming down these drains. Sometimes there are shelves or benches of fairly
> flat land perhaps as wide as 40' that step down the hillside to the fairly
> flat bottom of the hills.
>
> John, are you saying it is best to build a pond on TOP of the ridge, and
> trust that the ground will hold water from rainfall?
>
> My long ridge( 1/2 mile +) runs west to east with a fairly gentle slope to
> east. It is also for the most part 500' hundred or more in width. Like a
high
> plateau. It is also well very well drained...since there is little
standing
> water.
>
> Slopes are not that gentle...probably 8% or greater in spots near tops
less
> steep at bases of hills.
>
> <<If you mean damming up a gully/valley, this is the last/worst choice
> for where to build a pond.
> Basic reasons:
> * most likely to blow out (it's right where water naturally
> concentrates the most, and likely fast-moving water too... :-o)>.
>
> Oops! Your observations make sense. My initial thinking was to find places
> where water naturally flowed; and to use those as catch basins/ponds
higher
> up on hills. I thought I then could set up a series of 2 or 3 such ponds
to
> cascade by gravity down the hills so I could use them to water cattle,
> irrigate land etc.
>
> So what do you folks advise as to best locations? Don't have a scanner or
I
> would send you a topo slice of my area.
>
> <<> Heavy clay soils down here hold water very well.>> Yes, on the surface
> and also down below when dug. On the otherhand even after heavy rains
> sometimes only the top few inches are wet. We just dug some post holes
after
> a heavy rain...and was surprised to see that the soil from just a few
inches
> down was so dry. OTH we have had low soil moisture, droughty conditions
for a
> few months.
>
> <<So do you have a clay layer over something more permeable, or rock,
> or...?  I'm wondering if subsoil ripping to let water through a shallow
> clay layer might help...but what's underneath your clay?>> For the most
part
> I believe limestone based horizontal layers. Some are quite visible on
deeply
> carved hills alongside good size creek. On interior hills there are small
> areas of protruding rocks near tops that appear to have more granite like
> structure. Lots of small,coarse rock visible on surface.
>
> <<sounds like the combo of
> clay surface soil and water concentration are creating rapid runoff and
>  these boggy surface areas in the low spots?>> Absolutely and due to the
> gentle undulations there's a fairly large area( in total) of such boggy
areas
> that will hold water on surface for days.
>
> These areas do hold water on the land and pasture though. So while it is a
> real problem when wet...it probably has benefits as it dries. So I'm not
sure
> of just what to do:) since there are lots of these boggy areas created by
the
> various low spots. Even though the low spots are generally no more than a
> foot or two or 3 below surrounding land.
>
> Filling in or grading such large areas would be quite a task, and might
even
> create problems elsewhere.
>
> <<Slowing the water down
> and spreading it out (with keyline techniques) might help, if areas it
> currently runs off of can absorb and hold it in the soil (most
> efficient storage location) and/or ponds.>> To some extent I have done
this
> by grassing in some water ways, adding woody debris, and placing water
bars
> along trails coming down the hills to divert, and break force of water
that
> was eroding those trails.
>
> But there is SO Much more to do. I have over 300+acres of wood covered
hills
> that enclose the bottom land.
>
> I've gone into detail like this since such land is fairly common around
here
> and may be of interest to others with similar situations.
>
> And also I still haven't clearly understood though I agree with the
premises
> of key line design.
>
> Look forward to the lists' comments. Hopefully by concentrating on such a
> design others may benefit as well. Let's see some PC design in action so I
> can implement it:)
>
> Thanks again. May all of you find Peace and Joy in the coming Holiday
season.
> Frank in southern Kentucky.
>
>
>
> I'm not sure about subsoiling.
>
>
>
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