Drainage is important for all playground fall impact safety surfacing, and it's required for all that are publicly accessible, including community parks, schools, churches, synagogues, mosques or other similar locations. If it's an existing playground and there is a drainage system, it needs to be inspected to make sure it still works, to avoid potential flooding. If it's a new playground, or one where the old drainage system no longer functions, we've got to start from scratch.

The ground or soil is called sub-grade within the project area, into which goes the drainage system, with sub-base on top of that, then a sturdy geotextile fabric layer to separate the sub-base from whatever surface you're choosing. If it's rubber mulch, you need 6 inches of depth above the sub-base and sub-grade with drainage. For wood products or playground sand (silica), you require a 12 inch depth, and the sub-base & sub-grade/drainage needs to be underneath that.

Drainage commonly range from box drains with pipes for water evacuation, to French drains (pipes made with holes drilled in the sides) which also have to drain somewhere, and doing this can be rather costly. Another option could be as simple as creating water vaults, or pits that collect water that absorbs into soil naturally, at a fraction of other drainage systems. This all depends on your soil properties and ability to absorb and hold moisture, which could alter the sizing and spacing of each water vault. Typically one for every 250 to 300 square feet of overall area, at one cubic yard in size, filled with 3/4 crushed rock. You may need to adjust the square footage coverage for each water vault based on your weather and other environmental conditions. too. We've created a single-page PDF engineering cutaway drawing that's a helpful reference for creating water vaults for drainage within a playground installation.