Backfilling Flashboard Riser Inlet Structures

It’s completely normal and expected that the top of taller single-sided flashboard riser structures will be out in the water, away from the bank.

Six-foot flashboard riser in a pond.

Backfilled Soil will slump as the angle of the bank exceeds the angle of repose for the soil type.

On taller structures, excess backfill will slide into the water and in front of the box blocking the entrance of the riser.

This makes it more difficult to access the flashboards

Six-foot flashboard riser showing backfilled dirt.

Six foot flashboard riser with support frame showing backfilled dirt.

Diagram showing the proper placement of backfilled soil against a vertical structure, with an angle of repose between 30 to 45 degrees depending on soil type, indicating how to maintain stability and drainage.

More information on the forces affecting flashboard risers HERE

Soil slumping is not a problem with short and wide flashboard risers.

In-Line water level control structures eliminate problems with soil slumping.

2-foot flashboard riser showing backfilled dirt.