Inground Trampoline Drainage Guide
Drainage is the most critical — and most often neglected — aspect of inground trampoline installation. Get it right and your trampoline performs beautifully for years. Get it wrong and you have a swamp.
How Inground Trampoline Drainage Works
Three things need to work together for drainage to succeed.
The Gravel Base
A 4–6 inch layer of compacted gravel at the bottom of the hole gives water somewhere to go. Skip this and water has no escape route — it pools under the frame and accelerates corrosion.
The Retaining Wall Gap
Our retaining wall system is designed with drainage gaps that allow groundwater to move laterally through the wall. This is why you need a proper inground system — not a regular trampoline dropped in a hole.
Surface Grade
The surrounding lawn should slope away from the trampoline at all points. Even a 1% grade prevents rainwater from flowing into the hole. This is often overlooked and causes the most issues.
Soil-Specific Guidance
Your drainage solution depends heavily on what your soil is made of.
Sandy Soil
Drains naturally. A standard gravel base is typically sufficient. Minimal drainage concerns.
Clay Soil
Holds water. Needs a deeper gravel layer (6–8 inches) and may benefit from a perforated drain pipe at the base. Common along the Wasatch Front.
Caliche / Hardpan
Near-impermeable layer common in Arizona and southern Idaho. Must be broken through — a gravel base on top of intact caliche will not drain.
Loam / Mixed
Most common in residential yards. Standard gravel base with correct surface grade is usually sufficient.
High Water Table
If your yard is wet seasonally, a French drain or sump system may be required. Contact us to discuss your specific situation.
Rocky Soil
Rocky subsoil can affect excavation depth and drainage. Our crews are experienced with rocky conditions in mountain communities.
Not Sure About Your Drainage Situation?
Our professional installation crews assess every site before digging. We handle the drainage planning for you.