Particle shape shall be considered in approving beach fill. Material is to be examined to identify
whether particles are rounded or angular in shape. Rounded particles are acceptable for beach fill
because they most closely resemble native beach materials. Angular particles are not acceptable
for beach fill because sharp points and edges may cause discomfort while walking, sitting, or
lying on the beach, thereby affecting the aesthetic qualities of the beach (USACE 1984). A
sample from each potential beach fill source is to be visually examined for particle shape.
Acceptable material must be composed of 90%-rounded particles as estimated visually. Any
source containing greater than 10% of angular particles may be rejected.
Most beach fill material will be generated from the flood control debris basins and will need to
be cleaned of debris (trash, wood, vegetation, etc.). Also, material obtained from streambeds or
river courses may require screening of debris. The screening can be done by mechanically sifting
the material through a coarse mesh to catch debris at the site and further reworked using
conventional earthmoving equipment (Chambers 1992). Visual inspection of the source location
will be adequate for BEACON to identify whether debris screening is necessary. Debris
screening would be necessary if numerous trash or litter deposits are visible within the source
area and debris appears significant.
Compactability/Moldability of Proposed Beach Fill Material
Material that contains a visible component of iron oxides (a brown/red color) has a tendency to
form a hardpan when placed on the dry beach. Material with the tendency to form a hardpan will
be placed seaward of the mean high tide line to be reworked by waves. Reworking by waves will
result in rapid winnowing of fines from the beach fill leaving beach sand behind while fines are
transported away from the site by currents.
Beach fill activities may occur on short notice and when material becomes available.
Transportation of the sediment will be by trucks, train, dredge, conveyors, or other suitable
Trucking of suitable beach sand from potential sand sources will probably be the most efficient
transportation method for most sand source sites. Table 4.3 outlines the estimated number of
truck trips and frequency for each beach fill site, based on trucking the maximum proposed
volume at each site over a year. The majority of the flood control debris basins are located
sufficient distance to the beach fill sites that trucking would be the only feasible option. Other
potential sources that may require trucking to transport the material to the beach include upland
construction projects, dam decommissioning on the Ventura River, Mugu Lagoon restoration
projects, Callegus Creek sediment disposal projects, and landslide material.
Moffatt & Nichol Engineers