consists generally of sandy beaches backed by tidal lagoons and marshes, 
except at Seal Beach and Huntington Beach where plateaus 10 to 30 feet 
above sea level lie behind the beaches, The principal shore communities 
in the study area are Seal Beach, Huntington Beach and Newport Beach, but 
the population of Orange County and adjacent counties to which Orange 
County beaches are readily accessible is over 6,000,000. Of the shore 
frontage, 13.64 miles or 81.8 percent is publicly owned. The principal 
publicly owned sections are Bolsa Chica Beach and Huntington Beach State 
Parks and the municipal beaches in Huntington Beach and Newport Beach. The 
tides in the study area have a diurnal inequality, the mean and diurnal 
ranges being respectively about 3.7 and 5.3 feet. The maximum tide each 
year is about 7 feet above mean lower low water. Characteristic waves are 
swells generated in distant ocean areas. They have heights up to 10 feet 
and periods up to 20 seconds with the greater heights and shorter periods 
occurring in the winter. Winter waves generally approach the shore from 
upcoast of normal, summer waves frequently approach from downcoast of 
normal. As a result the predominant direction of littoral transport is 
generally toward the southeast. However, Seal Beach is protected from 
westerly waves by offshore breakwaters and the predominant direction of 
drift is now northwestward. Sand has been supplied to the shore by tribu- 
tary streams, especially during storm runoff, but the supply has been 
greatly reduced by construction of dams on those streams. 
The District and Division Engineers concluded that the most suitable 
plan of shore protection for the problem area from Surfside to Newport 
Beach comprises a protective beach in the vicinity of Surfside-Sunset Beach 
generally 500 feet wide and 9,200 feet long to be provided by artificial 
placement of approximately 3,000,000 cubic yards of suitable sand on the 
beach, construction of an offshore breakwater at Newport Beach and pro- 
viding periodic artificial nourishment of the Surfside-Sunset Beach shore 
by transferring sand from the impoundment area of that breakwater. They 
made an economic analysis of the plan of protection for the shore from 
Surfside to Newport Beach and concluded that the plan is justified by 
prospective benefits, and that in equity Federal assistance to the extent 
of 61 percent of the costs of protection of these shores is warranted. The 
District and Division Engineers recommended modification of the existing 
project to authorize Federal participation, subject to certain conditions, 
by contribution of funds in amount of 61 percent of the first costs and 
periodic nourishment and maintenance costs of the project. 
Residents of Newport Beach objected generally to construction of a 
breakwater off Newport Beach on the basis that there is presently no 
erosion problem at Newport Beach and that protective construction should 
preferably be located at Surfside, the site of the present erosion problem. 
Some also indicated that surf action at Newport Beach would be reduced and 
that use of the sheltered area behind the breakwater for navigational pur- 
poses would be objectionable. 
89 
