A Design Guide

Plan the Right Bunker Sand

Choosing the right bunker sand is only the first step. Proper sand depth and bunker design are essential for consistent playability, performance, and long-term maintenance. This guide helps you achieve the ideal playing conditions once your bunker sand has been selected.

Sand Testing

Always use an accredited lab to test potential sands. Key tests include particle size, infiltration rate, and specifically:

  • Angle of Repose (AOR): Determines the maximum stable slope.
  • Water Release/Column Test: Determines optimal moisture retention and sand depth.

Design & Slope Limitations

  • The 80% Rule: To prevent potential sand migration, avoid bunker slopes steeper than the sand’s AOR. To prevent sand from sliding/slumping off the face, keep slopes at or below 80% of the AOR.

Optimizing Sand Depth

  • Variable Depths: Bunker floors typically require deeper sand than the faces.
  • Microclimates: Sun, wind, and shade alter moisture levels. Adjust individual bunker depths to account for these environmental factors.
  • The Baseline: Lab data suggests that using a depth that retains 14% - 18% moisture after a 14 hour drying period produces ideal playing conditions.
  • Trial Bunkers: Try building a test bunker with varying sand depths to let stakeholders test and agree on desired firmness.

Face Depth & Lie Quality

  • Maintain Sand Depths: Ensure you have proper sand depths on bunker faces. Proper installation, compaction, and moisture keep this depth firm and resistant to erosion.
  • Fried Egg Lies: No sand prevents plugging completely. Dry sand, high-lofted shots, and over-raking all increase fried egg risks.

Testing & Shape

  • Penetrometer Variance: Labs use different testing metrics to predict plugging. For accurate comparisons, always test multiple sands through the same lab.
  • Particle Shape: A sand's particle shape is a primary indicator of its overall field performance.

Moisture & Irrigation Management

  • Moisture Balance: Excess water makes sand heavy; too little water makes it soft and fluffy.
  • Irrigation Design: Sand will not wick moisture upward. Dedicated mist heads, drip lines, or proper standard head placement are required to combat evaporation.
  • Effluent Water Risks: Recycled or high-nutrient water fuels algae growth in warm, wet conditions.

Droughty Sands & Maintenance

  • Droughty Sands: Sands lacking fine particles dry out and fluff up quickly. Because the BBB method prevents subgrade contamination, these sands stay dry and require additional irrigation.
  • Sustainability: Ensure the final bunker design allows the grounds staff to execute maintainable, sustainable routine care.
USGA Sand Selection Guide