To find the slope of your yard, you need to find the amount the ground rises over a given distance. This doesn’t require specialized tools or complex math. By using a few common materials, you can determine your yard’s slope in minutes.
- 2 stakes at least 36 inches long, marked at 1-inch intervals.
- Hammer or mallet
- Tape measure
Once you have determined the slope of your yard, you will then be able to tell if you need to increase the slope for proper drainage, or if it is adequate. You can also use this slope measurement to find out if your yard is level, then correct it if you desire to landscape a level lawn.
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7 Steps to Calculate the Degree of Slope in Your Yard
Finding your slope may seem daunting, but it can be done quickly and painlessly without help from a surveyor or math whiz. Rather than try to unravel formulas or engineering jargon, simply follow the steps below and you’ll find the percentage of slope of your property without a hassle.
Mark Your Stakes
Choose 2 pieces of wood at least 3 feet long. Once you have these, it’s time to turn them into giant rulers. Place a measuring tape alongside your wooden stakes and mark both stakes at 1-inch internals.
- Mark your stakes at 1-inch intervals and number the markings.
- Use a permanent marker that is bright, easy to read, and cannot be smudged.
- Make sure the stakes are marked equivalently—they should be twins once you’re done.
You’ve just made your own home surveying tools. A pair of well-marked stakes should be all you need for measuring the slope in most lawns.
Drive in Your Stakes
Use your hammer or mallet to drive one marked stake 6–12 inches into the ground at the top of the slope. Then, drive the second stake 6–12 inches into the ground at the bottom of the slope.
- Drive your stakes deeply enough that they are firmly in the ground and will not wobble or tip over. Keep in mind, they must be able to stand up straight when a string is pulled taut between them.
- Drive each stake the same distance into the ground. If you drive your top stake in 6 inches, drive your bottom stake in 6 inches as well.
Drive the stakes so that the line between them follows the course of whatever project you’re planning. For example, if you want to determine the slope for a drainage trench, have the line between the stakes follow the course of the planned drain. This will ensure an accurate reading.
Tie a String Between the Stakes
Once your stakes are firmly in the ground, tie one end of your string at the base of the top stake, at the first visible inch marker. Then, tie the other end around the bottom stake. At this point, eyeball a taut, level line.
- Tie the string in a straight, taut line between the two stakes.
- Make sure the string is not tied so tightly around the bottom stake that it cannot be adjusted up or down.
This eyeball measurement will get you most of the way there. Now, it’s time for the fine-tuning.
Make Sure the String is Level
Place your level along the taut string and determine the level. Then, adjust the string tied to the lowest stake up or down to achieve a level, taut line.
- A simple carpenter’s level is all that is necessary for determining the level of the string.
- Hold the level to the underside of the string when determining the level. This will prevent the level’s weight from warping or bowing the string and will ensure accurate calculation.
Take your time with this fine-tuning. If the string threatens to slip up or down on either stake, you can staple it in place to make the job easier.
Determine the Height Difference
Because you’ve marked your stakes and tied a level line between them, this step is simple. Just do the following:
- Determine the number of inches between the ground and the point where the string is tied to the bottom stake.
- Determine the number of inches between the ground and the point where the string is tied to the top stake.
- Subtract the number of inches found at the bottom stake from the number of inches found at the top stake.
- Example: 13 inches – 1 inch = 12 inches
- This number is your slope’s rise.
If one end of the string is tied to the bottom stake 13 inches above the ground and the other end is tied to the top stake 1 inch above the ground, the difference between the two is 12 inches. This means that over the distance between the two stakes, the ground rises 12 inches.
Measure the Length of the String Between the Stakes
Now that you have your rise, it’s time to determine the run. This part is easy. Use your tape measure to find the length of the level string that runs from the top stake to the bottom stake.
- Measure the distance of the level string (in inches) between the two stakes.
- Example: 10 feet of distance is 120 inches.
- This number is your slope’s run.
It’s important to measure the horizontal distance of the level string between the two stakes to ensure accuracy. If you measure the distance between the stakes along the ground, this will result in a larger number. It will not give you an accurate slope calculation.
Crunch the Numbers
Now that you have determined the rise and run of your yard’s slope, it’s time to calculate the percentage of slope. Here’s how:
- Dive the rise by the run. In our example, this would be 12 ➗ 120
- The result should be a decimal. In our example: 12 ➗ 120 = 0.1
- Multiply the result by 100 and put a percentage symbol to the right of it. In our example: 0.1 ✕ 100 = 10%
- The resulting number is the percentage of slope in your yard. A yard that slopes down 12 inches over a 10-foot span has a 10% slope.
You can use this tactic to measure slope from any point A to point B. No surveyor’s tools or software required. This number can then be used to determine if the angle of the yard is sufficient for structures like french drains, or if additional grading is required to increase the slope’s angle.
How Do You Find the Slope of Your Yard?
To find the slope of your yard, you need only some stakes, a hammer, string, a level, and a tape measure. This may not seem like much, but by using these simple tools you can determine the rise and run of your yard. Once you find these numbers, a very simple calculation will provide you with the percentage of slope.
Now that you know the angle at which your yard slopes, you can proceed with landscape projects to ensure proper drainage.