Despite vocal opposition, an artificial reef proposed off the coast of the Peninsula traversed its first hurdle — the first of 10 needed — this week.

On Tuesday, the California State Lands Commission approved an offshore lease sought by the Southern California Marine Institute. The institute is partnering with the National Oceanic and Atmospheric Agency in hopes the reef will attract and support the marine flora and fauna which once populated the area before landslides buried the natural rocky reef.

The agencies are proposing to use 72,000 tons of rock from quarries on Catalina Island, dropped at various points along a 69-acre area of coastline between Bunker Point and White Point at a depth of 15 to 21 meters.

The Portuguese Bend Landslide, triggered by road construction on Palos Verdes Drive in 1956, buried the natural reef and released sediment through the 1990s, according to a commission staff report. In 1999, efforts to stabilize the landslide significantly slowed the sediment release, but waves continue to stir sediment and compound the problem.

Another landslide at Trump National Golf Club in 1999 buried additional reef habitat and prompted more sediment release, the staff report said.

Proponents need approval from nine additional agencies, including the California Coastal Commission and the U.S. Army Corps of Engineers. Should they clinch them, construction could start as soon as May, said David Witting, a NOAA biologist and a leader on the project. However, a 2019 start date is more likely because weather, whale migration and lobster season limit the construction time frame to between May and September.

Residents and environmentalists say they are concerned construction could do more harm than good.

One big issue: The reef will be built 2 kilometers from the Palos Verdes Shelf Superfund site, an area where millions of pounds of toxic chemicals were dumped from the late 1940s to the early 1970s. Those chemicals — specifically DDTs, which were used as pesticides, and PCBs, which were used as flame retardants and insulators — have contaminated the coastline and harm fish and wildlife in the area.

Both substances were banned in the 1970s, but high concentrations of the chemicals remain in the Superfund site’s soil. Environmentalists and opponents worry reef construction could stir up the toxic chemicals or encourage growth in a contaminated area.

“Wouldn’t common sense tell you that you wouldn’t want to restore habitat in an area that’s contaminated like that?” said Rancho Palos Verdes Mayor Susan Brooks, who is opposed to the project in its current state.

But according to a staff report presented to the commission, the Superfund site is far away from and in much deeper water than the reef’s proposed location. And, the report said, the amount of contaminants in the proposed project area is measured at only “ambient levels.”

In addition, some fret construction — which will drop thousands of tons of rock into the sea — will somehow trigger another landslide. Witting said those fears are unfounded; the project site has no unstable subtidal landslides.

“The vibrations we’re causing are very minor compared to the day-to-day activities of cars and construction on land,” Witting said.

Yet another concern is that the reef is a temporary solution, that future landslides and sediment settlement will eventually bury it.

“The proposed project will do nothing to stop or redirect this downcoast flow of silt and sediment, which will likely result in any restored reef being quickly covered before any self-sustaining fishing habitat can be re-established,” said a letter written to the commission from Brooks, representing the City Council.

But according to the staff report, the reef’s tall size is intended to deter sediment from burying it. And wide sand channels will move sediment away with the currents. The reef’s design mimics nearby natural reefs that survived the landslides, according to commission staffers.

Although the Rancho Palos Verdes City Council supports the project’s aims, it does like the location of the proposed reef and has written two letters opposing it.

The funding for the project, which is expected to cost $6.49 million, comes from the settlement between NOAA and the Montrose Chemical Corp., which was largely responsible for the toxic chemicals in the water. The Montrose Settlements Restoration Program has about $15 million left in its coffers to spend on projects that restore natural resources to the areas damaged by the pollution.