Half Moon Bay harbor dredging to finish this week 

But the breakwaters have also caused issues, trapping sediment inside the harbor and making it more challenging for boats to get in and out. These environmental issues extend to adjacent beaches — a 2008 to 2015 study by the U.S. Army Corps of Engineers found seven times the rate of erosion at next-door Surfers Beach than nearby beaches further down the coast. 

That’s where the dredging project, which is moving 75,000 cubic yards of clean sand, comes in, Danitz said. 

A sand-water mixture called slurry is pumped up from the harbor and fed into pipes that deliver it to Surfers Beach, where water drains off and bulldozers move the sand toward Highway 1, which is directly at the beach perimeter. The dredging will provide clear benefits to boaters using the harbor, Danitz said. 

“This is by far the largest dredging that has occurred within the harbor since it was built,” he said. “All this sand that has built up over the past 40-50 years — or more actually — [that] is causing problems for navigation has been removed. So that was definitely a big benefit to the operations of the harbor.” 

While the negative impact of erosion at Surfers Beach is clear, the sand relocation was still done cautiously. It’s the first time a project of this nature has been attempted at a National Marine Sanctuary, Danitz said, so its impacts will be closely studied. 

“It’s a pilot project, so we’re trying to study how effective that would be, whether there be any unanticipated impact involved,” he said. “The idea is to look at the small- to medium-sized placement of sand and look at what the benefits are, and potentially, if it’s possible to do a larger project in the future.” 

Once the benefits and negatives have been adequately weighed, there could be potential for a larger dredging project in the future, however, it’s unlikely the San Mateo County Harbor District could finance it, Danitz said. 

“I could probably envision that a larger project, if it happened in the future, would be done by the Army Corps of Engineers,” he said.