2.1

2.2

2.3

2.4

Numerous studies by both the City of Oceanside and the LosAngeles District, Corps of Engineers, have been undertaken since the Department of the Navy constructed the Del Mar Boat Basin, along with accompanying breakwater and jetties, as a military installation in 1942, adjacent to the City of Oceanside. These studies were done initially in response to environmental and economic impacts caused by the military installation, but have included the implementation of recommendations for a civilian small craft harbor to help justify cost/benefit criteria.

By 1944 it had become clear that the north to south littoral drift that predominates along the coastline at this point created shoals in the military basin entrance channel, and that the military breakwater and jetties resulted in downcoast erosion of the Oceanside Beach. An initial study by the City in 1949 recommended that a small craft harbor be constructed and that its attendant jetties and groins be employed as a means of stabilizing downcoast beaches.

In 1958, the Los Angeles District, Corps of Engineers, issued an interim report confirming that the construction of a civilian harbor adjacent to the Del Mar Boat Basin at Camp Pendleton would benefit downcoast beaches and would not adversely impact on military uses. In 1963, the Corps of Engineers issued a survey report that the civilian small craft harbor conformed to Corps standards and would have been justified as a federal project. Federal maintenance was recommended.

The City of Oceanside in 1962 and 1963 created an inland
recreational harbor and dredged a harbor entrance channel to
the south of the military harbor and jetty. This allowed
3.8 million cubic yards of material to be dredged and placed
on the downcoast beach in an attempt to restore it to pre-
1942 configuration.
The attempt by the civilian
jurisdiction to assist in rectifying adverse impacts created
by the adjacent military installation, however, was of
limited success. By 1968, the dredged material was again

lost to erosion.

2.5

2.6

harbor.

In 1967 and 1969, the Congress authorized additional studies
by the Corps of Engineers to attempt to solve the downcoast
erosion and accompanying shoaling at the mouth of the joint
military/civilian
Several studies have been
undertaken in response. Studies have focused on beach
stabilization south of the existing harbor and on methods
for transporting sand around the harbor entrance in order to
reduce the shoaling in the harbor, as well as the potential
for expanding the recreational harbor facilities as a result
of certain jetty and breakwater modifications. A "Progress
Report on Navigation Study" was issued by the Los Angeles
District, Corps of Engineers, in June 1983, compiling work
done to that date.

Under Administration policy, placing recreational harbors at a negative priority for federal funding of Corps of Engineers civil works, the last Congressional appropriation for the Oceanside Harbor Navigation Study was made in 1982. About $680,000 had been spent on the study to that date, when it was estimated another $110,000 would be required to complete the study and to prepare the necessary Environmental Impact Statement on recommended modifications

to the existing breakwater and jetties.

2.7 In the meantime, work has begun by the Corps of Engineers, under Congressional authorization of an Operation Maintenance Project entitled, "Oceanside Experimental Sand Bypass System." An appropriation of $1.9 million was made in fiscal 1986 for this purpose, and work is in progress. This project calls for installation of a operating system of jet pumps and fluidizers to intercept sediment entering the harbor and to pump it via submerged pipes for constant nourishment to downcoast accordance with a report and recommendation by the Los Angeles District in 1982.

3.0 HARBOR DESIGN PROBLEM

3.1

continuously

beaches, in

Studies by military and civilian jurisdictions to determine if harbor facilities should be modified have focused on mitigating environmental and economic loss resulting from the original design flaws of the breakwater and jetties for the military Del Mar Boat Basin. Construction of the civilian harbor itself was justified partly by the perceived need for dredged material to correct downcoast beach erosion.

3.2

1969,

Planning studies authorized by Congress in 1967 and however, included potential expansion of the recreational harbor as a means of providing a beneficial cost ratio in support of modification of the breakwater and jetties, as well as to meet a growing public demand for recreational boating facilities. The potential of expanding the civilian harbor within the existing breakwater was made possible when the U.S. Marine Corps, which has jurisdiction over the harbor's turning basin area, declared that this area would not be needed for military operations and could be used for civilian harbor expansion. The studies established that Oceanside Harbor needed to be expanded in order to become self-supporting, and that there was substantial demand for expanded facilities. However, the Oceanside Harbor District is not seeking expansion of its facilities at this time.

harbor

3.3 Shoaling of the entrance channel and related wave surge problems also were well documented in the planning studies. The downshore littoral drift generally carries silt and sand from nor th to south. However, in certain seasons the reverse is true. It is estimated that some 200,000 cubic yards of material per year is trapped in the entrance, with much higher quantities moving north or south, depending on the season. Periodic maintenance dredging is required and its costs are shared by the Department of the Navy and the Corps of Engineers. The FY 87 President's Budget appropriated $480,000 to the Corps for this purpose. Depths in the harbor entrance change radically in response changes in sediment transport, fluctuating as much as 5 feet in a single day, causing navigation problems and creating areas too shallow for sailboats with fixed keels and for the larger commercial boats.

3.4

to

15

Ocean wave action at this location is dominated by northern hemisphere swells from late fall to spring and by southern hemisphere swells during other periods. Waves generally approach the shore from the southwest during both wave seasons. The harbor entrance is sheltered from waves by features of the coastline and by offshore islands which block deepwater waves from the north and northwest, but not sheltered from waves out of the south or southwest. Waves of from 6 to 10 feet are not uncommon in the area, and the harbor has an excessive surge problem during periods of heavy surf. When this problem occurs, the entrance, which is open to the southwest, becomes hazardous and boat slips in the harbor can be damaged. Surge may reach a height of 6 to 8 feet within the harbor entrance during winter storms. Shoaling in the harbor entrance complicates this situation by causing breakers to form as the waves cross areas of shallow water. Even experienced sailors and commercial boatmen have been swamped or overturned within the harbor breakwater under this circumstance, resulting in injury and loss of life as their craft are smashed against the jetty.