The Army Corps of Engineers has concluded that an experimental $12.3-million project is successfully restoring sand to Oceanside's eroded beaches.
Despite some discouragement when the innovative pumping system fired up last June, the corps now says it can distribute 120,000 cubic yards of sand a year and probably much more.
Dana Whitson, the city's project manager, said experts realized by December that the system had reached a milestone: "They were seeing sand build up at the beach."
Equally important, the system has shown that it can prevent sand from blocking the entrance to Oceanside Harbor, a problem that has required expensive dredging.
The results have the city and the corps optimistic that Oceanside's chronic beach erosion and harbor blockage problems can be solved if a $2.7-million second phase of the project is approved by Congress.
Beaches have eroded, sometimes down to bare rock, since Camp Pendleton's boat harbor and jetty were built in 1942, disrupting the natural southerly flow of sand onto Oceanside beaches.
Congress authorized the project in 1982, but pumping didn't begin until last June. Although the system quickly looked promising, it suffered equipment failures and annoying delays.
But the corps, waiting until the system had operated during some of the winter before deciding whether the state-of-the-art technology actually worked, has judged it a success.
The corps' report says that "the gradual increase in beach width at the disposal site . . . gives an indication of how the bypass can nourish the beach by continually supplying sand and simulates a more natural method of beach replenishment."
The system vacuums sand trapped at the entrance to Oceanside Harbor and the Del Mar Boat Basin at Camp Pendleton and pumps it south to the beach through a buried pipeline.
According to the corps, the system has moved up to 250 cubic yards of sand an hour, but the average production is about 80 cubic yards an hour, or 120,000 cubic yards annually.
Whitson and the corps have told Congress that the system is not operating at peak capacity, however, because the jet pumps leave a big hole where they suck up sand. Not as much sand can be sent to the beaches because "time is required for the waves and long-shore currents to refill the crater with sand in order to resume pumping," the corps said.
Whitson said an additional $2.7-million federal appropriation would pay for the installation of perforated pipes called "fluidizers" that would mix water and sand to quickly replenish the crater.
The sand-pumping project is vital to replenish city beaches that, because of their narrowness, have made coastal property vulnerable to storm damage, Whitson said.
"A wide beach is the best possible protection from storm waves," she said.