There are acres and there are acres

   / There are acres and there are acres #1  

dennis52

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After reading a lot of posts about calculating degree of slopes it occurred to me that this might be the place to provide some opinions about the measure of acreage.


Now my understanding is that the acreage on your property is what is called aerial acreage ; ie measured from looking straight down from above.

When people ask me about my farm I always joke that it is a big 25 acres and to work, it feels more like 30 acres.

I have about a third of steep land, a third of sloping and the rest is flat.

In this mix I have 2 twisting creeks, gullies and hollows.

I appreciate that sloping acres and creeks are harder and more time consuming work than flat pastures ( It feels bigger)

However is it actually true that a sloping acre can be more than the measure indicated on the title deed?
 
   / There are acres and there are acres #2  
It not only can be, it is more area than the deed says, but for most instances the increase is small.

If you have land which is perfectly flat, but tilted at 5 degrees to level (to an engineer, flat and level are different things) you would have about 0.4% more land than the plat indicates.

At 15 degrees, you will get 3.5% more area, but the land will be almost impossible to work.

The formula is: (area/plat area) = 1/cosine (slope) , where the slope is expressed in degrees.
 
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   / There are acres and there are acres #4  
It not only can be, it is more area than the deed says, but for most instances the increase is small.

If you have land which is perfectly flat, but tilted at 5 degrees to level (to an engineer, flat and level are different things) you would have about 0.4% more land than the plat indicates.

At 15 degrees, you will get 3.5% more area, but the land will be almost impossible to work.

The formula is: (area/plat area) = 1/cosine (slope) , where the slope is expressed in degrees.

So, 40 acres on a hill = ?:)
 
   / There are acres and there are acres #5  
I've always wondered about that. So if you have a piece of land, with a hill in the middle, you probably have more land than the plat says?

And related - say I have a stream bordering my land. There is a very steep slope to it. Is the epa limit boundary calculated "aerially" or by dropping a tape measure on the land? The difference is pretty decent.
 
   / There are acres and there are acres #6  
"So, 40 acres on a hill = ?"

Depends on the slope. Basic geometry.

Now, the hard question is whether a governmental Section on a level area in the mountains of Colorado is the same size as a governmental section on a level area at sea level.
 
   / There are acres and there are acres #7  
"So, 40 acres on a hill = ?"

Depends on the slope. Basic geometry.

Now, the hard question is whether a governmental Section on a level area in the mountains of Colorado is the same size as a governmental section on a level area at sea level.

Depends on flatness. Spherical geometry.
 
   / There are acres and there are acres #9  
Or, spherical geometry if it is not flat (but is sloped).
 
   / There are acres and there are acres #10  
Don't give the tax collector any ideas. We don't need a surface area tax.
 
 
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