Dredging Sought to Combat Erosion: Army Corps Confirms it Won’t Fund Project, Harbor District Takes Charge

As coastal erosion continues to threaten areas of the San Mateo County coastline with many suggesting the outer jetty at Pillar Point Harbor is exacerbating the degradation immediately south, locals have decided to take the reins after a federal agency declined to fund what some believe could be a solution — dredging the harbor.

Last month, the U.S. Army Corps of Engineers released its final report after a yearslong study confirming what many locals have long feared — the federal agency won’t pay to dredge the harbor. However, corps officials are suggesting they may be able to help the San Mateo County Harbor District’s efforts to lead a pilot program.

The Harbor District is closer than ever to embarking on the first project to dredge the harbor and use the sediment to help replenish sand immediately south at Surfers Beach. Over time, sand that would typically serve as a buffer between powerful waves and land gets trapped inside the breakwaters or jetties created to protect boats inside the harbor.

There may be environmental hurdles and the pilot will require extensive monitoring, but there’s an $800,000 line item proposed in the state’s budget to fund the San Mateo County project and district General Manager Steve McGrath said plans are proceeding nicely despite years of setbacks.

“We’re in a pretty good place right now,” McGrath said.

In 2015, the special district opted to become the lead agency for a new pilot program to remove 75,000 cubic yards of sediment that’s built up in the harbor and use it to replenish the beach. Due to it being located in the Fitzgerald Marine Sanctuary, a slew of environmental permits will be required and the wet sand must be strategically placed, likely above the high tide line — regulations prohibit dumping dredged material within sanctuary waters. It will also require extensive monitoring to determine how long the relocated sand remains and what kind of protection it provides, McGrath said.

The coastside has long been plagued by erosion, and many contend the damage immediately down current is due to sand from the beaches getting trapped inside the harbor. Originally, locals had hoped the U.S. Army Corps of Engineers would take charge since it constructed the outer jetty in the 1950s; but like most federal agencies, the corps had to follow strict procedures.

After a yearslong study, the U.S. Army Corps of Engineers officially released its final report last month that determined the cost of dredging the harbor wasn’t worth the benefit.

“We unfortunately determined that while in the big scheme of things it would be great to see that sand on the other side of the harbor, the costs of doing that compared with the benefits that would be realized were insufficient,” said Thomas Kendall, chief of planning for the U.S. Army Corps of Engineers San Francisco District.

Local effort

While the corps undertook the study, locals stepped up to make more immediate improvements, which may have had the unintended consequence of reducing the benefits dredging might have provided.

For example, Caltrans, the city of Half Moon Bay and the Harbor District recently completed a shoreline restoration project at Surfers Beach that involved placing rip rap along the coast to protect Highway 1.

“To the extent there’s been a good local response, yeah, it’s unfortunate in some ways because disincentivizing is probably a fair characterization for the feds to get involved. Because they’re going to prioritize where they can make a difference, and if the difference is already by and large made by local investment, it kind of leaves less on the table,” Kendall said.

Regardless, it does appear putting sand back on the beach is the right thing to do and the corps favors efforts to create a regional sediment management plan, Kendall said.

With that in mind, although the corps won’t fund actual “construction” or dredging costs, there are federal research and development programs that may be able to help with monitoring, he said.

“Going forward, it’s anticipated that the successful activity out there is going to [require] fairly extensive monitoring because it’s in the [marine] sanctuary,” Kendall said. “We have some [research and development] programs that we would propose tapping into to support that.”

McGrath said the proposed $800,000 state allocation would ideally cover planning as well as actual dredging, so any source of federal funding for ongoing requirements would be helpful.

“We look forward to any level of cooperation that we can possibly get from the Army Corps. The monitoring of this project is going to be extensive and long lasting,” McGrath said.

Questions remain

There will be various stages of monitoring, as well as looking at two main issues — is the sediment helping to reduce erosion and what effects might it be having on the marine sanctuary?

The harbor is located near protected waters overseen by the Monterey Bay National Marine Sanctuary, and is part of the Greater Farallones National Marine Sanctuary under the National Oceanic and Atmospheric Administration. McGrath noted a variety of complex environmental permits from local, state and federal agencies will be required. Sanctuary officials have provided positive indication they may support the project, although McGrath noted a monitoring schedule and detailed planning on where the dredged sand would be placed still needs to be outlined.

Exactly how beneficial the sand is to reducing erosion will also be studied, and it’s not yet known how long the one-time dredging of 75,000 cubic yards will remain at Surfers Beach or where it might go.

But getting answers will necessitate the $800,000 state funding, which McGrath hopes will be approved in the upcoming budget process.

The Harbor District’s proposed pilot program is less than the 150,000 cubic yard dredging the Army Corps considered. Although many were disappointed to hear the federal agency wasn’t expected to approve paying for the project having given indications several years ago before confirming it in this year’s finalized report, there could be a silver lining.

Extensive research and scientific studies conducted by corps experts may be useful as the Harbor District endeavors on its own solution.

“The Army Corps info has been useful,” McGrath said. “We were disappointed with the eventual determination that they could not justify federal interest in this project, but clearly it’s very important to the community as a whole and we’ll do our part.”

Source: Daily Journal