Oroville Dam New Details: How High Is the Water Momma? (Video)

Forecasters with the National Weather Service offered a stark warning Sunday for just about everyone living in the soggy, soaked Central Valley.

“Pretty much anybody needs to be prepared for the possibility that they may have to evacuate quickly,” said Sacramento meteorologist Brooke Bingaman.

Though most of the Valley had avoided further flooding by Sunday evening, the worst may be yet to come Monday and Tuesday, Bingaman said.

On Sunday, the weather service issued a flood warning in urban areas and along small streams through Thursday for the counties that make up the Sacramento and northern San Joaquin valleys, as well as for most of the counties that sit along the valleys’ rim.

“We may see flooding in locations which haven’t been impacted in many years,” the alert reads.

In other words, those living anywhere near a river, a slough, a levee, a creek or a canal need to be ready to flee floodwaters at a moment’s notice.

Case in point: Maxwell, a rice-farming town of 1,100 people an hour north of Sacramento. It flooded early Saturday as storm runoff overwhelmed a creek, filling a neighborhood and small business district with more than a foot of water.

Bingaman said the same scenario in Maxwell could happen in just about any low-lying area.

“We have been hit hard with storm after storm after storm since early January, so our soils are very saturated and it’s getting to the point where there’s no place for the water to go,” she said.

In Maxwell, the water was receding Sunday morning and only one person was still at a Red Cross shelter in nearby Williams, said Jim Saso, assistant sheriff at the Colusa County Sheriff’s Office. But with the next storm approaching, he urged residents to be ready to get out again.

“If they were affected (by the floodwaters) before, they’ll probably be affected again,” Saso said.

In Maxwell on Sunday, residents hurriedly stacked sandbags made from rice sacks around their houses as they prepared for that eventuality.

“It’s going to be worse than the last one,” said Richard Airozo, 77.

Firefighters awoke him about 4 a.m. Saturday with a knock on the door, as water was seeping into his garage.

By noon Sunday, he had returned to his house and removed soaked carpet from his living room. It was piled in a damp stack next to his driveway. Inside the house, a portable heater and fan were drying the room.

Kim Troughton, 52, spent Saturday and Sunday cooking meals for firefighters and police in Maxwell’s fire hall.

She said she wasn’t sure it made sense to start cleaning out her restaurant, Kim’s Country Cafe, before the next storm hit.

“If we get more water, it’s damned if you do, damned if you don’t,” she said. Instead, she planned to spend the afternoon laying sandbags around her house.

Two hours south in the San Joaquin Valley, locals nervously were watching the swollen San Joaquin River. The river at a critical measuring station near Vernalis, southeast of Tracy, had filled to “danger stage” Saturday night. That’s the point that emergency officials say water could overtop levees.

“We’re bracing for flooding,” said Jenny Rich, a spokeswoman for San Joaquin County. “We’re anticipating it happening.”

Low-lying areas near the river, which passes by Manteca, Lathrop, Stockton and Tracy, are all are at risk. But Rich said most of the troubles are likely to occur in southern San Joaquin County.

Along the river, between Manteca and Tracy, teams of volunteers have been patrolling levees every two hours, brushing up on emergency action plans, and filling some 900 sandbags at the San Joaquin River Club, a private community of more than 800 people, said Rick Hall, a 10-year resident who is helping lead the volunteer effort.

The hope was that the community could make through the next few days without hearing a blast from emergency sirens installed at the clubhouse and at a church that would warn of incoming floodwaters, he said.

“Everybody’s worried, of course, but we’re just trying to be proactive,” he said.

Some of the concerns are due to the precariously full Don Pedro Reservoir, which captures water from the Tuolumne River, a key tributary of the San Joaquin. The reservoir, which has more than twice the capacity of Folsom Lake, remained close to cresting Sunday. If it goes over the top of its spillway, it would send a gush of water that could overwhelm the small Tuolumne River channel, flood part of Modesto and cause the San Joaquin to rise.

Based on Sunday’s forecasts, the spillway could start sending out releases as early as Tuesday, said Brandon McMillan, a spokesman for the Turlock Irrigation District, which manages New Don Pedro Dam.

“Of course everything’s based on the weather, and that can change,” McMillan said.

Three and a half hours to the north, engineers at troubled Oroville Dam said Sunday that the lake is ready to handle the influx of water from the approaching storms.

Officials said Sunday that the lake levels continued to dip and are where they should be for this time of year to catch additional rain and melting snow.

The lake had dropped Sunday to nearly 50 feet below the dam’s emergency spillway.

On Feb. 7, during a round of winter storms, state engineers discovered a cavernous hole in the lower section of the dam’s main spillway, a 3,000-foot concrete span that acts as the dam’s primary flood-control outlet during the rainy season. Fearing the spillway would become inoperable, dam operators stopped the flows for a time, then gradually reactivated releases.

With runoff from the stormy Sierra Nevada still rushing in, reservoir levels climbed, and on Feb. 11, water overtopped the dam’s emergency spillway for the first time in its 48-year history. Unlike the main spillway, which is lined with concrete, the adjacent emergency spillway dumps water in uncontrolled sheets over a 1,700-foot concrete lip onto a steep, wooded hillside.

The next afternoon, a day and a half after the emergency system activated, the hillside just below the spillway lip was showing serious erosion, raising fears the structure would collapse. The concerns prompted mandatory evacuation orders in Butte, Yuba and Sutter counties covering nearly 200,000 people.

The orders were lifted Tuesday, after the state Department of Water Resources cranked up releases on the main spillway, despite the damage to its midsection, and managed to lower reservoir levels below the emergency lip.

On Sunday, the flows out the main, damaged spillway had been reduced to nearly half what they were during the heat of the crisis. Officials said the lower flows were allowing crews to use cranes and dredges to clear the debris that formed in the channel below the spillways. The debris has raised water levels in the Feather River below the dam to the point that Oroville’s power plant – the dam’s primary release outlet outside of flood season – can’t operate.

Once debris is cleared and the power plant is restarted, the facility is capable of draining another 14,000 cubic feet per second from the lake.

“We’re shooting to be able to re-operate it a week from Monday if we need to,” said Chris Orrock, a spokesman for the DWR, which manages the dam. But he noted “it’s not a guaranteed date.”

Meanwhile, despite the wet weather, crews continued to haul rock and cement into the eroded areas below the emergency spillway in case it needs to be used again.