Water collection locations on this site
J.F. Sebastian
Posts: 12
Location: Inland NW, USA, Earth
posted 2 years ago
I've done a lot of permaculture (and related) tinkering and reading over the years, but I don't have a great eye for overall macro-scale earthworks yet. Can somebody with a bit more experience tell me what I could do to hold water on a decent scale on this site, images below? Preferably higher up in the property, but I'll work with what I can get in a reasonably cost-effective way.
It is an odd property, mostly a grassy SW-facing hillside, mixed hay/wheat currently with a bit of timber in back. Total around 105 acres, annual avg rainfall 24", elevation ~3000ft, located in inland NW, USA. Cold med climate, we get all our rain from October to May with little over the summer. SW prevailing winds around here, so it is somewhat exposed. Haven't dug much yet but well digger reports in the area indicate there is a deep layer of clay under the topsoil.
It isn't marked, but contour lines are 10' -- the hill is fairly steep at points.
Thanks for the comments! Sorry for the lousy graphics...
It is an odd property, mostly a grassy SW-facing hillside, mixed hay/wheat currently with a bit of timber in back. Total around 105 acres, annual avg rainfall 24", elevation ~3000ft, located in inland NW, USA. Cold med climate, we get all our rain from October to May with little over the summer. SW prevailing winds around here, so it is somewhat exposed. Haven't dug much yet but well digger reports in the area indicate there is a deep layer of clay under the topsoil.
It isn't marked, but contour lines are 10' -- the hill is fairly steep at points.
Thanks for the comments! Sorry for the lousy graphics...
Nuno Donato
Posts: 18
Location: Portugal
2
posted 2 years ago
Hi J.F.!
What a coincidence, I just posted a while ago talking about a way to help people like you.
http://www.permies.com/t/40205/rainwater/Simulating-rainfall-water-catchment-usage
Sounds like a good way to test it out. Do you have a high resolution image of the contour lines or satellite image?
What a coincidence, I just posted a while ago talking about a way to help people like you.
http://www.permies.com/t/40205/rainwater/Simulating-rainfall-water-catchment-usage
Sounds like a good way to test it out. Do you have a high resolution image of the contour lines or satellite image?
J.F. Sebastian
Posts: 12
Location: Inland NW, USA, Earth
posted 2 years ago
Hi there! I just knocked the above images up in Sketchup -- I don't really know how to use it beyond the very basics, and the contour data is from Google Earth. I can certainly create the above at a much higher resolution -- the contour lines will still be 1px wide, so it should be more precise. How big do you need? Do you want the terrain removed (just contour)?
Nuno Donato
Posts: 18
Location: Portugal
2
J.F. Sebastian
Posts: 12
Location: Inland NW, USA, Earth
Nuno Donato
Posts: 18
Location: Portugal
2
J.F. Sebastian
Posts: 12
Location: Inland NW, USA, Earth
Nuno Donato
Posts: 18
Location: Portugal
2
posted 2 years ago
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well my technique for modelling from contour lines is harder than expected, this was a good training. still some research to do.
can you just check this rough video quickly and see if I got the elevations right?
https://www.youtube.com/watch?v=PzpwntPJKiI
can you just check this rough video quickly and see if I got the elevations right?
https://www.youtube.com/watch?v=PzpwntPJKiI
J.F. Sebastian
Posts: 12
Location: Inland NW, USA, Earth
Nuno Donato
Posts: 18
Location: Portugal
2
posted 2 years ago
I've embedded the video below for you.
How permies.com works
What is a Mother Tree ?
Nuno Donato
Posts: 18
Location: Portugal
2
posted 2 years ago
thanks!
and here is a still shot with the contour lines visible.
http://i.imgur.com/kwA2wZr.jpg
Swale effect: http://imgur.com/a/0oLxS
Please don't forget, there are plenty of mistakes in this simulation because it was done quickly and roughly, just to try out and see how the whole thing "feels". A real case would have taken much longer as the contour lines would need to be modelled perfectly (which was not the case in this one
and here is a still shot with the contour lines visible.
http://i.imgur.com/kwA2wZr.jpg
Swale effect: http://imgur.com/a/0oLxS
Please don't forget, there are plenty of mistakes in this simulation because it was done quickly and roughly, just to try out and see how the whole thing "feels". A real case would have taken much longer as the contour lines would need to be modelled perfectly (which was not the case in this one
J.F. Sebastian
Posts: 12
Location: Inland NW, USA, Earth
posted 2 years ago
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Hey, that effect is awesome! I like it! That sort of thing could be quite helpful for a landowner, and definitely for a designer that they could show as part of their presentation to a client -- if you could streamline the process you could probably sell it.
A few observations:
* The lines aren't quite right, as you say. Overall it is quite good, but I see a few places where the water flow doesn't line up with what it should be doing based on the contour lines or the landscape. Doesn't matter here, as this model plus the contour maps give me a good idea of what is happening.
* I think it would be needed overall to take into account not just what falls on a property, but also rainfall onto the catchment area that *drains into* the property. In my case that isn't such a giant difference since I'm nearly at the top of the butte (and anyway I didn't give you maps that included that data), but in most cases this is where the majority of the flowing water comes from, and it can make modeling just the direct rainfall quite misleading depending on the terrain.
* If you could sanely model potetial dams and swale flows, that would be *extremely* helpful to people, I think
* Overall a steeper camera angle looking into the land is more useful (my opinion, at least). The tilt and pan is slick, but I expect the most valuable view is probably a top-down fixed look.
* I like it!
* I wish this property had better dam sites in the top half. The only natural spot my amateur eye sees in the top half is in a deeply forested gully/thicket, so damming it would be hard and overly disruptive. There is also a small spring or seep in there I think, which needs further exploration.
A few observations:
* The lines aren't quite right, as you say. Overall it is quite good, but I see a few places where the water flow doesn't line up with what it should be doing based on the contour lines or the landscape. Doesn't matter here, as this model plus the contour maps give me a good idea of what is happening.
* I think it would be needed overall to take into account not just what falls on a property, but also rainfall onto the catchment area that *drains into* the property. In my case that isn't such a giant difference since I'm nearly at the top of the butte (and anyway I didn't give you maps that included that data), but in most cases this is where the majority of the flowing water comes from, and it can make modeling just the direct rainfall quite misleading depending on the terrain.
* If you could sanely model potetial dams and swale flows, that would be *extremely* helpful to people, I think
* Overall a steeper camera angle looking into the land is more useful (my opinion, at least). The tilt and pan is slick, but I expect the most valuable view is probably a top-down fixed look.
* I like it!
* I wish this property had better dam sites in the top half. The only natural spot my amateur eye sees in the top half is in a deeply forested gully/thicket, so damming it would be hard and overly disruptive. There is also a small spring or seep in there I think, which needs further exploration.
posted 2 years ago
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I know this is a far less hi-tech solution, but I wanted to very quickly summarise some of the stuff geoff lawton teaches in his PDC, and also in his earthworks course, about choosing a dam site. Basically, he says to look out for contour lines that make a shape like this.
Please excuse my total lack of drawing skills. Also, the highest land is at the top of the image.
Then remember that water always flows downhill, at right angles to the contour lines. Something like this.
So in this case, most of the water falling on the land would find its way to the area inside that inverted-horseshoe shape contour line. Which also has a conveniently narrow 'neck' across which to build a dam.
Which would then fill up like this.
The course gave a whole load more info on calculating how much water would be collected and details on the actual construction, but I thought a quick visual might be useful to some people. Even if it's not exactly the eye-candy that Nuno produces.
Please excuse my total lack of drawing skills. Also, the highest land is at the top of the image.
Then remember that water always flows downhill, at right angles to the contour lines. Something like this.
So in this case, most of the water falling on the land would find its way to the area inside that inverted-horseshoe shape contour line. Which also has a conveniently narrow 'neck' across which to build a dam.
Which would then fill up like this.
The course gave a whole load more info on calculating how much water would be collected and details on the actual construction, but I thought a quick visual might be useful to some people. Even if it's not exactly the eye-candy that Nuno produces.
How permies.com works
What is a Mother Tree ?
Nuno Donato
Posts: 18
Location: Portugal
2
posted 2 years ago
1 - right,as I said,it was just a quick test, not a perfectly made model
2 - definitely! when planning water you should have a big picture of where water comes from, you should know what exactly is your watershed. Of course a watershed can be a HUGE things (dozens, hundreds? of miles), so we need to find a balance between perfect and do-able
3 - yes, that is the plan
4 - yeah, the pictures are nice, but I plan to make the top-view maps, especially in maps where main waterflow lines are represented.
5- cool
6 - why dams and not other earthworks?
J.F. Sebastian wrote:Hey, that effect is awesome! I like it! That sort of thing could be quite helpful for a landowner, and definitely for a designer that they could show as part of their presentation to a client -- if you could streamline the process you could probably sell it.
A few observations:
1- The lines aren't quite right, as you say. Overall it is quite good, but I see a few places where the water flow doesn't line up with what it should be doing based on the contour lines or the landscape. Doesn't matter here, as this model plus the contour maps give me a good idea of what is happening.
2- I think it would be needed overall to take into account not just what falls on a property, but also rainfall onto the catchment area that *drains into* the property. In my case that isn't such a giant difference since I'm nearly at the top of the butte (and anyway I didn't give you maps that included that data), but in most cases this is where the majority of the flowing water comes from, and it can make modeling just the direct rainfall quite misleading depending on the terrain.
3- If you could sanely model potetial dams and swale flows, that would be *extremely* helpful to people, I think
4- Overall a steeper camera angle looking into the land is more useful (my opinion, at least). The tilt and pan is slick, but I expect the most valuable view is probably a top-down fixed look.
5- I like it!
6- I wish this property had better dam sites in the top half. The only natural spot my amateur eye sees in the top half is in a deeply forested gully/thicket, so damming it would be hard and overly disruptive. There is also a small spring or seep in there I think, which needs further exploration.
1 - right,as I said,it was just a quick test, not a perfectly made model
2 - definitely! when planning water you should have a big picture of where water comes from, you should know what exactly is your watershed. Of course a watershed can be a HUGE things (dozens, hundreds? of miles), so we need to find a balance between perfect and do-able
3 - yes, that is the plan
4 - yeah, the pictures are nice, but I plan to make the top-view maps, especially in maps where main waterflow lines are represented.
5- cool
6 - why dams and not other earthworks?
J.F. Sebastian
Posts: 12
Location: Inland NW, USA, Earth
posted 2 years ago
This property and landscape is mostly suitable for pasture/silvopasture and livestock. It is a brittle landscape. Swales are critical here for slowing water and keeping it infiltrating on the property, and I think if it were affordable some keyline plow subsoil ripping would be very helpful...but those both store water in the soil (not a bad thing). Animals, irrigating individual sections during our dry summers, and fire protection (a real concern) on the other hand all require surface water, and that means a dam. High up means I can move the water where i want with gravity. Down low it would need to be pumped, which adds complexity, cost and maintenance.
I could put large cisterns up high on the hill (and probably will) but in this environment cold winters means they will freeze unless they are mostly underground...which makes installing them much more expensive.
I could put large cisterns up high on the hill (and probably will) but in this environment cold winters means they will freeze unless they are mostly underground...which makes installing them much more expensive.
brad millar
Posts: 102
Location: Menifee, CA
9
J.F. Sebastian
Posts: 12
Location: Inland NW, USA, Earth
Nuno Donato
Posts: 18
Location: Portugal
2
J.F. Sebastian
Posts: 12
Location: Inland NW, USA, Earth
brad millar
Posts: 102
Location: Menifee, CA
9
posted 2 years ago
From the designers manual, page 231 " 20%- Moderate; usually accepted as the maximum slope for safe cultivation and erosion control; wheeled tractors are used at about 18%. The maximum slope of good road surfaces is accepted as 13%; anything over this should be concreted or sealed."
I agree with Sebastian, anything over 18-20% becomes too costly (especially on broad acre sites).
I agree with Sebastian, anything over 18-20% becomes too costly (especially on broad acre sites).
Nuno Donato
Posts: 18
Location: Portugal
2
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