NATURAL BEACH PROFILE ADJUSTMENT AND SCARPING

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7_BEACON Tech Report (FINAL)

3.6.3

Timing and Placement Rate

Placement at Hueneme Beach is proposed for Fall-Winter placement only (i.e., between

September 15 and March 15) because of it's proximity to least tern and snowy plover nesting

areas (See Appendix B). For the same reasons as outlined for Oxnard Shores beach fill site,

Spring-Summer placement at a location adjacent to nesting areas it is not recommended.

Therefore, it is proposed to avoid potential impacts to least terns and snowy plovers and place

sand during the Fall-Winter months when beach fill construction will not have an impact.

3.7

NATURAL BEACH PROFILE ADJUSTMENT AND SCARPING

For each design concept, the post-construction beach fill profile will be steeper than the pre-

construction beach profile, but will naturally evolve toward an equilibrium average nearshore

slope which is a function of sediment and wave characteristics. While the concept designs in

this report specify that construction profiles are approximately 15:1 or 10:1, the beach fill will

naturally disperse over a wider portion of the beach and nearshore zone resulting in a flatter

profile. Flattening of the slope and profile adjustment causes reduction of the berm width from

the post-construction profile. Figure 3-19 illustrates this concept. Although sand may move

away from the profile by waves and currents, the concept design profiles shown in this report

represent the maximum envelope of sand placement across the beach for purposes of permitting.

The level of protection afforded by the additional beach area after natural profile adjustment may

remain approximately the same as that provided immediately after beach fill construction. This

occurs because water depths will decrease in the nearshore zone causing waves to break farther

from shore, reducing wave runup elevations at the beach from pre-project conditions.

Periodic re-grading of the post-construction beach fill may be required to minimize scarping.

Bulldozers can be used to reduce a vertical scarp, which may form as waves rework the seaward

edge of the beach fill slope.

3-8

Moffatt & Nichol Engineers