DEL MAR, Calif. (AP) — Officials are gearing up for an ambitious and expensive plan to stabilize seaside bluffs near San Diego that have been plagued by a series of collapses over the past 18 months.

The stabilization effort kicking off next month is the largest of its kind for the Del Mar bluffs in nearly a decade, the San Diego Union-Tribune reported Monday.

The San Diego Association of Governments and North County Transit District have already dedicated roughly $10 million to repair stormwater drainage structures, replace parts of sea walls and install additional steel and concrete support columns to hold back the earth.

In December, the two agencies asked the state for another $100 million to ensure the safety of bluffs, the newspaper said.

Top state officials have recognized the need for stabilization projects and are now also calling to accelerate a long-envisioned plan to relocate coastal railroad tracks inland — a project that could cost as much as $4 billion.

SANDAG Executive Director Hasan Ikhrata said that his agency could be ready to start building a train tunnel through Del Mar in just three years.

“To keep spending money on temporary solutions isn’t a solution at all," he said.

A section of bluff in Del Mar collapsed on Nov. 29, 2019, just feet from the tracks.