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Geoff Lawton's "Check Dams" Video is up

 
Michael Cox
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Location: Kent, UK - Zone 8
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Check Dams video

 
Jennifer Wadsworth
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Location: Phoenix, AZ (9b)
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Unfortunately there is no short version of Check Dams in the Desert, however it's a REALLY good video on how those of us in drylands can sequester water in broad landscapes. AND - it is filmed in the beautiful Sonoran Desert!! (even better). You will need your email address to sign in to Geoff's site.

Important points in desert water harvesting strategies:
--Reduce evaporation! The definition of a dryland is that there is more evaporation than precipitation.
--Slow, spread and sink the flow. Water usually comes to the desert in downpours that don't have a chance to soak in.

 
Michael Cox
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This is a pretty nice video - long standing check dams built in a narrow channel. Behind them has built up 20ft depth of sand which is trapping water which plant roots can access. At the bottom of the series of check dams is a perpetual spring and year round water.

This particular location is undeveloped in terms of it's planting, which could be altered to make more productive use of the abundant soil moisture.

Similarly I imagine that a trickle irrigation system could be installed if the trapped sand and silt were used as a reservoir to extraction.
 
Bret Glassett
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Location: Grass Valley, CA
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Are check dams really beneficial to natural systems or are they actually disruptive? As I watch the video I'm thinking that check dams are all great - but I also recently watched the documentary DamNation and it points out the many issues with using dams and how they disturb natural watersheds. What's the difference? Are check dams okay only on seasonal drainages? Or?
 
Shawn Harper
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Location: Portlandia, Oregon
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Bret Glassett wrote:Are check dams really beneficial to natural systems or are they actually disruptive? As I watch the video I'm thinking that check dams are all great - but I also recently watched the documentary DamNation and it points out the many issues with using dams and how they disturb natural watersheds. What's the difference? Are check dams okay only on seasonal drainages? Or?


I would argue that logic is human biased. By that I mean there where a lot more beaver dams around until the mountain men hunted them to near extinction. Who knows what a natural watershed actually looks like?
 
Michael Cox
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Bret - check dams are quiet different from the type of dams discussed in that video (mostly large Hydro-electric installations by the look of it?). The purpose of a check dam is to slow the flow of surface water and reduce erosion during major spate events. Depending on the circumstances you might be talking about a one a year flash flood in a gully of the like.

The effects of these events are usually short lived as the water has rapidly flowed away down stream and out to sea. With a check dam a portion of that surface water (and a pretty small portion at that!) is held back in the silt and soil behind the dam wall where it spreads laterally to the surrounding soil and down stream. Where these systems are used plants can thrive on the increased soil moisture and whole ecosystems can be revived.
 
Neal Spackman
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There is a lot of controversy over check dams in watershed restoration circles. The folks at Quivira Coalition, as well as Neil Bertrando and Brad Lancaster, have spoken out against check dams in favor of boulder weirds, one-rock dams, and other tools that you can read about in "Let the Water Do The Work". The main argument against check dams is that the seed of their destruction is a result of their main function; eventually the rocks in the check dam erode away from the trickling water and the whole thing collapses in a wash.

In my own work, I have built hundreds of check dams and rather than relying on the structural stability of the stone, intend to use taprooted and shallow-rooted plants to stabilize the structures as they retain more and more water. I think with plants stabilizing the hydrology and slowing down erosion, and by using large boulders instead of small stones, we can avoid the pitfalls of check dams and create structures that will last a very very long time.

Check dams are not for the untrained to use though; they're tremendously easy to do poorly, but poorly done they almost never function well. Furthermore, I don't think they should be used at all in eroded gullies, but in more stony and mountainous regions where erosion is less likely to undercut them.
 
Dan alan
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Location: Tyler Texas
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forest garden greening the desert
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I was saving a copy of the most inspiring videos from these short videos, but I have a partition accident and lost them all. I don't see this video on his website.

Where can I find this video now?
 
Blake Campbell
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Dan Alan,
I also am looking for this video.  I have torn the internet apart and can't find it. 
I think I have the entire classic geoff lawton library minus this one and keep thinking about it.
Let me know if you have any success.  My gmail address is USAblake.
Blake
 
Dan alan
Posts: 99
Location: Tyler Texas
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forest garden greening the desert
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I still have not found it..

I wish he had not taken down all the videos.  It's nice to plug into some inspiration when I'm not seeing any abundance yet..
 
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