Choose the location for the playground carefully. Find the flattest possible area to reduce excavating costs and overall yard stability.
Determine how much of the playground can be built up as opposed to graded. In other words, if you can create a playground surface with the requisite 8 to 12 inches of safety mulch by building a wooden platform that is taller downhill and shorter uphill, this is much preferred. Removing soil can destabilize slopes and requires much more attention to erosion control and drainage issues.
Excavate that ground that cannot be built up via structural building downhill. Use the backhoe to dig away and create a wall on the uphill side of the playground. Only dig as deep as is necessary to get a relatively flat plane for the playground. Use the bulldozer to flatten the area, depositing excess dirt to build up the downhill side.
Install flexible black plastic drainage pipes that run from the area just above the excavated zone down to the area just below the playground. This will help minimize alterations in water drainage.
Build retention walls out of stacked landscape stones at the uphill and downhill edges of the playground. These will prevent erosion into the playground.
Compact the soil using the tracks of the heavy machinery.
Proceed with playground installation under normal circumstances once the level surface area has been prepared.