The coastal area is drained by a number of short, steep, intermittent streams 
which contribute sand and gravel to the shore during floods. The coast 
highway and the railway generally parallel the shore at the foot of the erosion 
resistant sea cliffs. The coastal plain is very narrow except for the 
Carpinteria plain with a maximum width of 2 miles and length of about h miles 
at the upcoast end of the area. A State beach park has been developed at 
Carpinteria. The development of the shore area in the remainder of this 
section is relatively minor. Three short sections of shore are publicly owned 
and are used for park purposes. Although most of the shore of this area 
has been reasonably stable during historic time, encroachment of the highway 
on the beach has necessitated its protection by seawalls and groins. 
b. Ventura River to Point Mugu - This portion of the coast comprises 
about 21.5 miles of shore extending generally in a northwest-southeast 
direction. The coastal plain includes the deltas of the Ventura and Santa 
Clara Rivers, which bring large quantities of materials to the shore, 
especially during flood periods. It gradually widens from the mouth of the 
Ventura River into the broad, flat Oxnard Plain, The Ventura-Pierpont 
Bay shore, lying between the mouths of the Ventura and Smta Clara Rivers 
is publicly owned or is in process of acquisition for park purposes. This 
stretch of shore line alternately advances and retreats due to the irregularity 
of supply of material by the Venture and Santa Clara Rivers. This instability 
limits the development of this shore area, The jettied entrmce to Port 
Hueneme lies about midway between the Santa Clara River and Point Mugu. The 
jetties have caused accretion to the west and erosion east of the entrance. 
The erosion east thereof and recommendations for remedial measures have been 
covered by a recent report on Port Hueneme and therefore were omitted from 
the present study. 
The tides in the area are diurnal, the diurnal range being 5.3 feet 
and the mean range 3.7 feet. The principal wave action affecting the area 
is from the west and northwest. The direction of predominant littoral drift 
is downcoast (southeastward). A relatively constant supply of material, 
estimated at 250,000 cubic yards annually, arrives at the problem area by 
littoral movement along the shore from northwest of Ventura River. The 
large quantities of material supplied at irregular intervals during floods 
by the Ventura and Santa Clara Rivers cause variations in the position of 
the shore line in the Ventura problem area. The shore line in this area 
since 1855 has been seaward of its position in that year, but, in general, 
it has receded since 1927. Investigations of shore waters in the Carpinteria 
area since 197 have indicated sewage pollution in this area and resulted 
in closing a portion of the beach. Planning is in progress for a new treat- 
ment plant which may be expected to remedy this condition. Although the 
Ventura sewage treatment plant operates satisfactorily, some contamination 
of the ocean waters occurs after high stages in the Ventura and Santa Clara 
Rivers. 
The district engineer developed a plan for protecting the shore at 
Ventura. He made an economic analysis of the proposed work and found that 
benefits from prevention of loss of beach area, creation of additional land 
48 
