These are without a doubt some of our most impressive and impactful work. I just returned from one of our mature (1.5yrs old) sand dam sites this past month. The community has huge terraced gardens up both sides and a hand pumped well that has not gone dry (it's sunk directly into the sand bed) for a year. This is in the middle of a desperate 3-yr drought. Everything else around is dry. They are not an anomaly. We hear similar news from the other sites as well.
Here's a quick link to the 90 or so we've worked on with our local teams. Google Earth recently updated their SAT pics, so many of these are highly visible in great resolution from an objective observer.
Can you comment on what will happen to that community when the hand pumped wells go dry? (assuming this is inevitable?) The best argument I've seen against what you are doing is that you are moving farming from sustainable areas to unsustainable areas. But I don't know much at all about the topic.
> Can you comment on what will happen to that community when the hand pumped wells go dry? (assuming this is inevitable?)
Why do you assume this is inevitable? Was there something in the video that made you think these will go dry?
> The best argument I've seen against what you are doing is that you are moving farming from sustainable areas to unsustainable areas.
Are you under the impression that people are moving into the areas that these things are being built?
What does sustainable farming mean for you? (For a lot of westerners it means (nearly) free energy being used to produce synthetic fertilisers combined with broad pesticides, servicing large monocultures with little to no attention to improving soil quality, severe erosion from bare soil practices, etc.)
Yes, and I still don't know much about the topic. Hence, the questions.
> Why do you assume this is inevitable? Was there something in the video that made you think these will go dry?
Dude, I don't know much, so I'm signposting the potentially incorrect assumptions I might be making, to help out whoever wants to answer my questions. You have a smug attitude, but I don't see you attempting an answer. What's up with that?
> Are you under the impression that people are moving into the areas that these things are being built?
No, and you appear to be missing my point if you think that is necessary for the criticism to hold.
> What does sustainable farming mean for you?
For the purposes of this discussion, enough water in perpetuity.
> Dude, I don't know much, so I'm signposting the potentially incorrect assumptions I might be making, to help out whoever wants to answer my questions. You have a smug attitude, but I don't see you attempting an answer. What's up with that?
Okay, that's my fault. What you interpreted as smug should have come across as frustration. Most comments in this thread are evidently from people who didn't watch the video, threw in some assumptions, and declined to do a brief web search.
If you look elsewhere in the comments you'll see an earlier comment from me that likely fills in your gaps.
Can I suggest that rather than loading your questions like 'What happens when these fail- I assume they fail' you could ask 'How long will these last?'
Wikipedia's 'sand dam' article would answer that question. They're designed to go for 50+ years. (I expect they'd actually be serviceable a fair while longer.) In any case, you'd presumably be building others up or down stream.
Noting that the problem here is not what happens in 50 years (assuming what you're doing now doesn't jeopardise 2 gens forward) but rather what happens in the next few years -- specifically providing sustainable water, food, health, societal benefits to people who need those things now.
You suggested I was missing your point, but to be candid I wasn't sure what that was -- do you mean your criticism of the project because you didn't know if it was sustainable?
Sustainable farming is about a lot more than 'enough water in perpetuity' - it's about nutrient capture / cycles / management, resilience, minimising external inputs (f.e. pesticides, town water, fertilisers etc -- while insects, birds, dust, wind, rain, sun, nutrients from retrieved by grazing animals are usually considered freebies).
Note that most conventional / western / broad acre / industrial / monoculture farming by definition is not sustainable, regardless of water abundance.
It's fun to consider just how sustainable are the practices of generating the food you eat, especially in 'the west'.
> You suggested I was missing your point, but to be candid I wasn't sure what that was -- do you mean your criticism of the project because you didn't know if it was sustainable?
A variety of reasons spring to mind. It's unproven (most support is anecdotal, with few if any rigorous studies available), possibly performs no better than bunds / swales / keyline, requires a lot of maintenance (rebuild every few years), is better for short-term crops than the preferred tree / forest crops for these sites that will be more resilient to regular droughts, risk of introducing non-native pest species.
I've heard of efforts to "jumpstart" a system through usage of a one time organic import. Geoff Lawton's project in Jordan of Greening the Desert fame comes to mind. Also there are expeyyriments in applying compost from the Marin Carbon project.
You're absolutely right. I've even heard senior permaculture types suggest superphosphate for use as a one-hit kick-starter .. but as I say, Hügelkultur is not a particularly well proven method, and I suspect its primary benefits are enjoyed in an area with regular & frequent rainfalls.
For bang-for-back (or bang per kilogram, as transport may be the biggest expense in these environments) something like biochar would be a good import.
Guaranteed pest-free, lightweight, hard to make on-site, etc. Nutrient loss won't be as severe as in a heavy rainfall environment, but what little there is here you'd want to lock up before the next big rains.
It's actually amazing in scope.