OXNARD SHORES

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7_BEACON Tech Report (FINAL)

Sediment samples collected at this site show the median grain size (D50) for the composite sand

sample is 0.192 mm with 4% fines. The offshore region from 24 to 30 feet contained the

largest percentage of fines ranging from 13 to 17%. Since this site is located immediately

adjacent to the Ventura River mouth, beach fill with up to 35% fines is proposed for this site.

Also, this site has a wide cobble berm that exists naturally, therefore cobble-sized material is

desirable for placement at this location. This project could serve to periodically repair the cobble

fill placed by the City in 2000.

3.4.2

Design Scenarios

The beach fill material will be placed below the mean high tide line (if sand) or as a layer over

the beach surface as a berm (if cobble) as described in Section 3.1.2 and shown in Figure 3-12.

A typical berm at the Surfer's Point site would be elevated to near +10 feet above mean lower

low water (MLLW) and extend 100 feet seaward, then slope at 15:1 (H:V) to the water. If a high

percentage of cobble is used to build the berm, the beach would be built with a steeper slope (i.e.,

up to 10:1 (H:V)). The City indicates a steeper slope of 5:1 did not perform well for cobble

placement completed in 2000 (Parsons, personal communication 2001)

3.4.3

Timing and Placement Rate

Placement at Surfer's Point is also proposed for Fall-Winter and Spring-Summer placement.

Similarly to the Oil Piers site, it is proposed that two-thirds of the sand can be placed during the

winter months and one-third during the summer. This allows for the sand to be introduced to the

littoral cell similarly to the natural cycles of the Ventura River. At this site, the rate of sand

placement for the 175,000 cy per year maximum annual limit is 116,700 cy during the winter and

58,300 cy during the summer as outlined in Table 3.1.

3.5

OXNARD SHORES

The Oxnard Shores beach fill site is located in the City of Oxnard, in Ventura County at the end

of West Fifth Street (Figure 3-13). The beach fill site is a public beach with access at West Fifth

Street and other points to south. Recreational activities include surfing, swimming, walking,

fishing, and boating. Oxnard Shores is bordered by the Pacific Ocean to the west, residential

homes to the south and east, and McGrath State Beach to the north.

3.5.1

Proposed Quantity and Quality of Beach Fill Material

The plan view of the Oxnard Shores site is shown in Figure 3-14. The plan shows a beach fill

length of approximately 5,600 feet beginning just south of McGrath State Beach and extending

south. The maximum annual volume of material proposed for this site is approximately

250,000 cy.

Sediment samples collected at this site show the median grain size (D50) for the composite

sample is 0.21 mm, with a fines content of 6.3%. Higher fines content is found from the 24 to

-30-foot contours, which ranges from 14 to 37%. Due to the proximity of the Santa Clara River,

which is a main sediment source to the littoral cell and conveyor of vast quantities of fines, beach

fill with up to 35% fines is proposed for this site.

3-6

Moffatt & Nichol Engineers