Calculate the correct grade away from the walkout basement. A 2 percent grade means the level drops away two units for every 100 units. For example, if the distance from the walkout basement to the edge of your yard is 100 feet, to achieve a 2 percent grade, the level of the soil should be 2 feet lower at the edge of your property than it is at the basement door.
Position a transit on level ground where you can clearly see the basement walkout area and a spot 100 feet out. Level the transit by adjusting the head until the bubbles in the level are centered.
Have your assistant hold a grade stick, which is a long stick with visible measurements used by surveyors, next to the basement.
Focus on the grade stick when looking through the transit, and instruct your assistant to put a mark, or a piece of tape, where the cross-hairs that you see through the transit align on the grade stick.
Ask your assistant to carry the grade stick to the spot 100 feet out from the basement and hold the stick so the measurements face you and the transit. The transit head will swivel, but do not move the tripod on which the transit sits.
Look through the transit again and ask your assistant to put another mark or piece of tape where the cross-hairs fall on the grade stick. For a 2 percent grade, the second measurement should be 2 feet higher than the first. If the second measurement is 1 foot higher, you will remove 1 foot of soil. If the measurement is 1.5 inches higher, you will remove 6 inches of soil.
Slope the yard with heavy equipment, such as a skid steer or a front-end loader, scraping away soil or adding and compacting soil until there is an even slope away from the walkout basement to the edge of the yard.