SAN FRANCISCO — California residents piled sandbags outside their homes and anxiously watched stream levels as the season’s 12th atmospheric river arrived on Tuesday morning, threatening to bring another round of flooding and chaos to the beleaguered state.

An unrelenting series of storms this winter have already shattered some weather records in California and prompted Gov. Gavin Newsom to declare an emergency in 43 of 58 counties.

While the storms have largely replenished reservoirs after a historically dry three-year stretch, they also have wreaked havoc. In the central part of the state this month, atmospheric rivers have repeatedly flooded neighborhoods, forced people to evacuate and closed major highways.

On Sunday morning, residents in two communities in Tulare County were ordered to leave their homes after several levee breaches occurred, Sheriff Mike Boudreaux said. They are bracing for more rain this week.

To the west, near the coast in Monterey County, the Pajaro River submerged local farms and forced the closure of Highway 1 after a levee broke. And to the east, in the Sierra Nevada, the relatively warm rain from atmospheric rivers has added weight to piles of snow, which threatened to collapse roofs and cause avalanches.

Here is what photographers across the state have witnessed so far this month:

A helicopter transported large sandbags to be used as barriers along parts of the Tule River to prevent levees from breaking.

Rescue crews marked flooded cars after they were checked for survivors near Tulare.

A large branch broke off a tree and landed on two vehicles as the storm swept over the Bay Area. No one was injured.

Jose and Monique Silva Hernandez, who are siblings, placed sandbags outside their home in Alpaugh, where many of the surrounding roads flooded and prompted evacuations.

Members of the California National Guard filled up sandbags and handed them out to residents in Alpaugh on Sunday.

Fields near Highway 43 have been flooded because nearby lakes and reservoirs are reaching capacity in Tulare County, and water is spilling onto adjacent farmland.

Kristen Vogt and her dog, Roo, waded through water to get to their house after the San Joaquin River caused flooding in Manteca.

A sinkhole caved in near a condominium complex in La Habra.

Heavy rainfall in San Clemente caused a landslide below an apartment building.

Floodwaters from the Pajaro River surrounded a home.

Members of the California National Guard prepared for Governor Newsom’s arrival at a news conference on the flood damage in Monterey County.

A creek flooded a residential road in Malibu.

Steven Kirk, above, and Roberto Martinez installed wooden sheathing outside New Moon Natural Foods to prevent further snow damage in Tahoe City.

Residents braved the rain and fog for a morning trip to the grocery store in Running Springs.

Barbie Gomez organized donations at the Watsonville Church of the Nazarene for displaced Pajaro residents and those living temporarily in nearby evacuation shelters.

Floodwaters continued to rise in Pajaro after a levee broke.

Pajaro residents looked across the river at the flooded town after law enforcement cut off access to the area when it flooded.

A duck swam through floodwaters on Salinas Road in Pajaro.

Pamela Cerruti collected laundry baskets outside of Pajaro Coin Laundry, which she and her husband own with their daughter, as the business flooded.

A breached levee was being repaired on the Pajaro River in Monterey County.

Mammoth Lakes Fire Department firefighters responded to a propane heater leak and small fire at a shuttered restaurant surrounded by snowbanks in Mammoth Lakes.

Snow piled on homes in Mammoth Lakes in the wake of a storm that passed through the Sierra Nevada.

Snowdrifts swallowed businesses in Mammoth Lakes.

Cristian Nunez shoveled a snowbank at a motel in Mammoth Lakes.

Floodwaters in Pajaro engulfed a vehicle when a levee initially broke.

A portion of Interstate 580 was closed because of standing water on the road in Oakland.

Workers made emergency repairs to part of a road that was washed out in Soquel.

Businesses in Mammoth Lakes were buried in snow.

Rafaela Rendon sat on a cot in a library at Rim of the World High School in Lake Arrowhead. The library served as a shelter for those displaced by the snowstorm.

Members of the California National Guard and employees of the California Department of Forestry and Fire Protection removed snow from the roof of the United States Postal Service building in Crestline.

Snow capped the mountains near Lake Arrowhead.