Introduction: Backyard Grading Survey
TL/DR: Screwed up my yard, need to fix, check grading first...
I used to have a beautiful lush green backyard. The grass was cool, smelled great, and fun to play on with the kiddos. Then I started screwing it up. First I built a giant, short lived, playset for the kids. Then I unsuccessfully attempted to plant a fruit tree. THEN I put up an above ground pool several summers in a row. All of these shenanigans led to a potholed, half dead, terrible lawn. So I decided to scrap it all and convert it to a hybrid desert landscape. I say "hybrid" because sure it will be desert-ish (lots of rocks) but will also have a waterfall, river, and pond. So after I successfully killed the lawn I needed to survey the damage. What I suspected was that after years of digging holes, filling holes, running sprinklers, and moving rocks I had drastically changed the grading of the yard. There are clear drainage points on the south east corner of the yard and any rain runoff does tend to go that way, but not very effectively. If I was going to build the mighty Nickissippi (trademark pending) I was going to need to make sure the yard sloped from the future waterfall down to the future pond. I'll admit, its not like we're talking about a 10 acre lot, I can clearly see the obvious high spots, but those can be deceiving when trying to judge overall slope of a section of land. I set out to survey the highs and lows of the yard.
- Laser Level
- Some sort of stick (1 yard)
- Tape Measure
- Forced Labor (bored children)
Step 1: Preparing the Tools
With a tape measure and a pencil I made a quick sketch of my backyard and then prepared a simple digital drawing using Bluebeam. The yard is approximately 44 feet x 41 feet. I divided the yard in to 4 foot squares figuring this is all the resolution really needed for this purpose. I grabbed a pole that's used for changing light bulbs and created one inch marks from one end. Its a big ruler. If you have a yard stick then just use that. The last tool needed was a laser level. The one I have is a pretty cheap model, no frills. It self levels and is fairly bright.
Step 2: Setting Up the Laser
I have a stack of bricks in my back yard about 36 inches high that was perfect for setting the laser on top of. The next part needed to wait until the sun went down. The laser is bright, but not THAT bright so it need to be a little darker outside before it would show up on the ruler. After the lighting was right I had my daughter move the ruler from square to square and call out the measurements. I didn't grid out the yard physically with string, or surveying paint. Instead I kept the spacing with a tape measure. My son recorded all of the numbers.
Step 3: Transferring and Displaying the Data
Once the measurements were completed I started transferring the data to my computer. You'll notice the handwritten numbers are different from the numbers on the computer. The ruler was marked 0" - 50" from the bottom. This meant that the higher the laser hit the ruler the lower the elevation. My daughter was calling out the actual inches measured but these were meaningless really without a zero reference. I used the highest number, thus the lowest elevation as my zero point. The highest number was in the far south east corner at 43" so this was my "zero". All of the other numbers were represented as the difference between the "zero point" and that points actual measurement. Example if we measured 37" then that point was represented as a value of 6 (43 - 37).
After filling in all of the squares with the calculated values I assigned each value a color on a gradient from yellow (highest) to dark blue (lowest). Technically the white square was the highest point but it was an extreme outlier since there is big pile of dirt there.
Step 4: Analyzing the Data
As you can see, the grading is a mixed bag of terrible. In general the yard slopes correctly, but its all over the place in spots. I would get less of a river and more of distributary (its a thing, look it up). If i'm going to get the mighty Nickissippi (trademark pending) flowing in the right direction I've got my work cut out for me.
There you have it, I took what was really a very simple visual observation and turned it into...science? engineering? math? Well it was exercise for the kids for a few minutes.
Participated in the