OCEANSIDE — The city has declared a local emergency after observing a significant buildup of sand (known as shoaling) in the harbor channel, prompting the U.S. Army Corps of Engineers to seek congressional funding for out-of-season dredging.
The City Council adopted a resolution ratifying the emergency proclamation on Nov. 19.
In late October, the city asked the Army Corps to survey the harbor channel after officials observed breaking waves across the entrance — a sign that ocean swells are dragging over increasingly shallow depths, according to Coastal Zone Administrator Jayme Timberlake.
The channel serves as the navigable entrance to Oceanside Harbor and Camp Pendleton’s Del Mar Boat Basin, framed by the harbor breakwater and the city’s north jetty, which the Army Corps refers to as the south jetty.
“North jetty is a fairly known hotspot for sediment accumulation or shoaling, oftentimes seen at depths of 7 or 8 feet prior to the annual dredging of the channel,” Timberlake said.
Currently, the left side of the channel along the breakwater is about 14 feet deep and remains navigable, though Timberlake said that could change quickly. Other sections of the channel are roughly 10 feet deep.
“This is the primary area of concern due to the potential for more sediment that may have accumulated northward and outside of the breakwater, which is likely to get mobilized by northwest swell energy and move into the channel where it could settle out and shoal on that breakwater corner,” she said. “This additional sediment in the channel could then create a more uniform shoaling across the entire channel, which would limit navigation by vessels.”
Annual dredging typically takes place in the spring, and the sand is used to replenish Oceanside beaches. The harbor channel was dredged to 30 feet in May — a “drastic change” compared to current conditions, Timberlake said.
More sediment is expected as winter approaches. Increased rainfall generates runoff, and northwest swells push sand from the Santa Margarita River toward the harbor.
“We can expect to see sediment move from out of the Santa Margarita River, along the harbor breakwater and settle out in the calmer waters of the channel,” Timberlake said.
The U.S. Coast Guard has closed other channels once depths reach 6 feet, a threshold Oceanside Harbor could reach if conditions worsen.
The emergency declaration allows the city to begin immediate dredging with support from Camp Pendleton. The Army Corps plans to return in December to resurvey the channel and use the emergency proclamation to request federal authorization and funding for off-cycle dredging.
Annual dredging is expected to resume in the spring, if needed, or shift to the fall.
Timberlake said Manson Construction is currently dredging the Channel Islands Harbor.
“Once they are complete, they can come to us,” she said.
The Army Corps will cover the cost of emergency dredging. Sand from the project is permitted for placement between Surfrider Way and Tyson Street Beach.
Oceanside resident Steve Maschue supported the emergency action, noting that other boat owners in North Coast Village, where he lives near the harbor, back the decision.
“We’re a hundred percent in support of getting this thing done,” he said.
The harbor has more than 900 boat slips.
Another resident, Dirk Ackema, urged the city to consider stockpiling sand at El Corazon Park for future emergencies.
“Recent nourishment at Tyson Street has shown the benefit of a few thousand cubic yards of sand. Especially if dredging is moved to the fall, it could lead to a situation where, in the spring, there might not be a whole lot of sand on the pier area beaches for our events,” he said.
Tyson Street Beach, south of the Oceanside Pier, received thousands of cubic yards of sand earlier this year following the city’s annual spring dredging of the harbor.
