Bayview Sand Mine - HATCHELL-Berm ConstructionDetail

Berm Construction Details

Bayview Sand Mine
Powells Point, NC
Currituck County
Narrow-based berm
The narrow-based berm is the most common berm having a top of 2 feet (0.6 m) and side slopes of two
horizontal: 1 vertical. This berm is the most economical to build as it requires the least material. The
steep side slopes of this type of berm eliminate the possibility of working on it with farm machinery.

Berm Construction
The berm construction comprises of the scraping back of the topsoil from the area where the berm and
storage basin is to be built. A subsoil material, free of stones, rubble, stumps etc. and with at least 10%
clay should be used to construct the berm. The material for the berm may be obtained from the area
behind or in front of the berm location or moved from a borrow pit located elsewhere on the farm. An
earth mover will be required to move material from a pit located a distance away while a bulldozer
would be used if material is located in the berm area.
The berm material is to be placed in layers and compacted as each layer is added. After the berm has a
final shape the sides of the berm should also be compacted.
Emergency Overflow
To provide for larger-than designed peak flows, an overflow system is used, namely:
• "The level-top vegetated berm crest" which provides for very flat berm top so that the water will
overflow along the berm length in a thin layer so as not to create erosion problems.

Ken Elliott, consulting
December 3, 2017