WATSONVILLE, Calif. (KRON) — Highway 1, a major corridor connecting Santa Cruz County to Monterey County along the coast, was shutdown for four days because of flooding south of Watsonville.

The California Highway Patrol said a storm-triggered levee breach on the Pajaro River eroded an embankment around Highway 1’s Pajaro Bridge. Floodwater spilled onto the roadway and destabilized the bridge.

Commuters breathed a sigh of relief on Wednesday afternoon when state officials announced Highway 1 will reopen in all directions by Thursday morning.

CalTrans wrote, “Southbound lanes of Highway 1 are expected to open (Wednesday) evening, and northbound lanes are estimated to reopen by (Thursday) morning. Construction crews are clearing debris and making final checks across the north and southbound bridges in advance of this reopening.”

“Travelers on Highway 1 can expect delays and lane closures over the course of the next months as crews work to reconstruct eroded embankment material around the bridge supports,” CalTrans officials wrote.

An atmospheric river poured rain over the region before water from the Pajaro River breached a levee about five miles upstream Saturday. Thousands of residents were evacuated from Pajaro when floodwaters swamped surrounding farmland and neighborhoods.

Caltrans officials wrote, “Flooding from this breach overflowed the highway on Sunday, March 12 which led to its closure.”

Emergency crews put up barricades diverting drivers off Highway 1 northbound at Salinas Road on the Monterey County side of the border. Barricades also diverted drivers off Highway 1 southbound at Highway 129 (Riverside Drive) on the Santa Cruz County side of the border.

A long, winding detour was in place for several days.

The detour funneled southbound drivers through Watsonville on Highway 129 east, over to Highway 101 south through Prunedale, then Highway 156 west through Castroville, before finally reconnecting with Highway 1. The reverse of this detour was the only option for northbound drivers.

Highway 1 crosses the Pajaro River via two bridges. As they cross the river, the bridges pass over two levee embankments. Caltrans officials said water flowing from the upstream levee breach eroded embankment material around the bridge supports, exposing foundation piles.

Monterey County officials gave the following updates on efforts to repair the Pajaro River levee breach:

• Crews filled a 400-foot-wide gap with rocks. This will stabilize the gap and prevent expansion. Water will continue to flow out of the river into the community of Pajaro, but at a slightly reduced rate.

• Once the width is covered, work will begin to build up the wall to meet the levee height. This work will take 1-2 weeks to complete.

• Work will continue at the site around-the-clock unless storm conditions become too dangerous.