Moises says that the size of the canal is limited by labor availability. In other words, he didn't have enough time to make it bigger, but he contends that the canal could be at least twice as big as it is now, perhaps even larger. I don't know the slope, we'd have to measure it...

Make the canals as big as you see fit, and we can investigate some animal traction possiblities sometime in the future.

Also, I recommend you start writing in the wiki. If you do it little by little as you go, it will save you mountain of work in the long run.

Here's what I've got so far for the design. I want to play around with it a little more to smooth out the canals and make them line up better with the watersheds, but this is pretty much what I think we can do with the property. I included potential atajado sites as well to show what I was thinking because it didn't make sense to have canals that run off into nowhere.

Some notes about the design:
·Capturing runoff on the land around the galleria is difficult because diversion or irrigation ditches can’t cross the galleria and we also can’t take water from the galleria and store it. But seeing as there are already a fair number of canals and atajados to build on the property already, it might be better to pump water from atajado 5 to drip irrigate that area-- OR
Depending on the actual location of the galleria and the contour lines (which may not be completely accurate from the map, since it looks like it flows uphill), it might be possible to connect the existing atajados to atajado 5 as I have drawn with canal 4- this would be ideal because it would collect more runoff and the area below the canal could be flood irrigated- so for this, I’ve pretended like the galleria is not there, and Frank, Moises, and Greby can assess what can really be done with it.

·I’ve drawn an atajado to intercept Moises’s canal (Atajado 6)- it can be a small one or a storage tank (a tank might actually work better, with the canal flowing into the top and then out on the other side (it might be necessary to use a pump system instead of a lockpipe because if the lockpipe comes out the bottom it may at too low elevation for the water to flow into the old atajado as it does now)- the advantage of this is that by storing the water at that point and being able to control its flow, the area below it could be flood irrigated- this will of course have to be done carefully (might want to create an irrigation paddock) in order to avoid flooding compound 2- it could also be done with drip irrigation.

·Atajado 3 isn’t really necessary because there won’t be a lot of water in it, but it would allow for irrigation below that area (we might consider just a small storage there instead).

·Atajado 8 and atajado 5 are “final” atajados (they have no outflow canals)- water from these atajados can be pumped for use in drip irrigation around the compounds (where flood-flow is impossible).

I've also done some calculations to estimate how large the canals will need to be to accomodate heavy rainfalls (November) without a lot of erosion within the canal. It looks like a sort of triangular shape with gently sloping sides and a width of around 2.5 meters should be good, and a slope of around 1/300 (this is what Ken and P.A. Yeomans recommend). I'll post the spreadsheet I've been using for that too, so you can play around with it.

Let me know if anything looks off or if you have any suggestions or questions.

I've been writing up notes about what I'm doing as I'm going along, but it's not really in a readable form that flows well, so once I get it into something coherent (which I'm working on now), I'll put it up on the wiki.

Okay, let's try that again. This should have all the data (plus the spreadsheet with my calculations). Sorry about that.

With the spreadsheet in there it was too big. THIS should be it.

Why did you change the coordinate system? Your canals use GCS South American 1969, and your other files are using NAD 27.

Although the stuff lines up in ArcMap, the coordinate systems are wrong and this makes it impossible to use to files you created with AutoCAD.

I'll see if I can change it by simply assigning the correct coordinate system, which is Provisional South American datum 1956 (PSAD 56), a UTM projected coordinate system. We are working in UTM Zone 20S.

When you create a new file with ArcCatalog, its important to assign it the coordinate system that we are using from the beginning.

Also, please post your spreadsheet or email it.

After converting the data to PSAD 56 none of it lines up. I'm sorry to say that you'll have to start over. Yes, there are tools that will allow you to convert from one coordinate system to another, but these tend to be mathematical models created for more common conversions, like NAD 27 to GCS 84. PSAD 56 is quite an obscure datum.

The process of creating new shape files and _layer_s goes something like this.

1. Open ArcCatalog, browse to the folder where you want your file to be created, right click inside the Content window, and browse down to New ->, it will give you a list of different things you can create. Click on shapefile.

2. Now you can choose a name, a file type (point, line, polygon, etc.), and a coordinate system.

3. To select the coordinate system, click Edit, Select, Projected Coordinate Systems, UTM, Other GCS, Prov. S. Amer. UTM Zone 20S.prj.

4. Alternatively, you can leave the coordinate system blank, open ArcToolBox, and use the define coordinate system tool if you like, but this seems more of a round-about way of doing it to me.

That's it. By far the most common mistakes people make when using GIS are with coordinate systems. Even professionally published data doesn't line up sometimes. So its pretty important to use the same coordinate system in all of your files from the beggining of the project.

If you have any questions, please let me know. Greby and I are going to take a look at what you've done and we'll probably have some suggestions in the next day or so.